Chronological Studies & Dating Methods


    absolute dating

       period - 0 - 13.7 b. bp

       mode - physical properties of item being dated provide a numerical age

       synonyms - chronometric dating, calendar dating, numerical dating


    aeolian geomorphology - see geomorphology

       period - 0 - 2 m. bp

       mode - wind generated change

       materials - sediments, quartz grains, soils, loess, sand dunes

       measures - wind history, erosion, deposition, climate change, environmental dynamics


    aerial archζology

       measures - temperature, flora, elevation differences from flight


    age equivalence dating

       mode - contemporaneity established age association


    age equivalent stratigraphic markers

       period - 0 - 4 b. bp

       mode - widespread physical remains of dated events or horizons provide

           age equivalence to the statigraphic column


    26Al/10Be surface exposure dating

       period - 100 -10 m. bp

       mode - cosmogenic nuclide accumulation

       materials - desert glass, manganese nodule, coral, surface rock, quartz, artifacts

       measures - exposure history, erosion history, manganese nodule growth rate,

          fault slip rates, seawater residence times, coral erosion rates, uplift rates,

          occupation history, glacial motion, volcanic events, rockslide events,

          sedimentation rate

       synonyms - 26Al dating, 10Be/9Be dating

       labs – 1) LDEO Cosmogenic Nuclide Group

          2) Purdue Rare Isotope Measurement Laboratory


    26Al dating – see 26Al/10Be surface exposure dating


    26Al/26Mg dating

       period - 4565 - 4571 m. bp

       mode - extinct radionuclide 26Al produced an excess of 26Mg

       materials - meteorites, feldspar, CAIs (Ca-Al-rich inclusions), chondrules, plagioclase,

          eucrites, chondrites, achondrites, pre-solar nebula fossils, hibonite, ureilite, angrites,

          melilite, anorthite, olivine, mesosiderite, pyroxene

       measures - early solar system, solar nebula dynamics, meteorite ages relative to CAIs

       labs - Isotope Laboratory of the Department of Geosciences and Arkansas Center for Space

                   and Planetary Sciences at the University of Arkansas, Fayetteville


    algal growth layers 

       mode - yearly growth layers

       materials – arctic algae deposits

       measures - climate reconstruction


    alkenone paleothermometry

       mode - biochemical record varies with time

       materials - ocean sediments, phytoplankton, sapropels

       measures - sea surface temperature, CO2 and nutrient availability, paleoclimate,

          Heinrich events



       period - 0 - 4 b. bp

       mode - a mappable stratiform body of sedimentary rock defined and identified on the

          basis of bounding discontinuities (NASC)

       materials - alluvial and lacustrine deposits, glacial deposits

       measures - emplacement of alluvial and lacustrine deposits, physical

          records of glaciations, emplacement of discontinuous terrace deposits


    amino acid geochemistry - see amino acid racemization


    amino acid geochronology - see amino acid racemization


    amino acid paleothermometry - see amino acid racemization, paleothermometry


    amino acid racemization

       period -

           asparagine - 0 - 25000 bp

           isoleucine - 5000 - 2 m. bp

       mode - when the organism dies, control ceases and the ratio of D/L amino acids

          moves slowly toward equilibrium

       materials - desert varnish, proteins, tissues, bones, shells, sediments, organic

          substances, dentine, eggshells, ostracodes, foraminifera

       measures - age, authenticity, age at death, sedimentation rates, date of death,

          climate change, temperature history

       synonyms - ostrich eggshell dating, L-amino/D-amino ratio, eggshell dating,

          amino acid geochemistry, amino acid paleothermometry, amino acid geochronology,

          aminostratigraphy, aminochronology

       labs – 1) Amino Acid Geochronology Laboratory – University of Massachusetts


    aminochronology - see amino acid racemization


    aminostratigraphy - see amino acid racemization


    ammonite biozone dating

       period - 65 m. - 400 m. bp

       mode - genera-specific horizon markers

       materials - marine sediments, ammonites

       measures - paleoecology, sediment emplacement


    annually laminated sediments - see varve chronology


    anthropological age analysis

       period - 0 - 100000 bp

       mode - skeletal age related changes

       materials - bone, teeth

       measures - body age

       synonyms - anthropological method


    anthropological dating

       period - 30000 - 4 m. bp

       mode - hominid geochronological dating associations

       labs – 1) Berkeley Geochronology Center


    anthropological method - see anthropological age analysis



       period - 0 - 5 m. bp

       mode - study of humanity and its ancestors


    apatite fission track dating – see low-temperature thermochronology, fission track dating


    40Ar/39Ar - see argon-40/argon-39 dating


    40Ar/39Ar geochronology - see argon-40/argon-39 dating


    40Ar/39Ar thermochronology - see argon-40/argon-39 dating



       period - 0 - 35000 bp

       mode - species markers

       materials - plants

       measures - plant use and associations

       synonyms - paleobotany, paleoethnobotany


    archaeological pedology - see pedoarchaeology



       period - 0 - 35000 bp

       mode - study of recent human development

       labs – 1) Archaeology & Quaternary Research Laboratory (AQRL), Department of

                  Earth & Environmental Systems at Indiana State University

           2) Missouri State Center for Archaeological Research


    archaeomagnetic dating - see paleomagnetic dating



       period - 0 - 35000 bp

       mode - correlations and sourcings applied to archaeology

       materials - tephras, obsidian, chert, clay, pottery, basalt

       labs – 1) University of Missouri-Columbia, Archaeometry Laboratory

           2) University of Tennessee Center for Archaeometry and Geochronology


    archaeozoology - see zooarchaeology


    argon-39 dating

       period - 40 - 2000 bp

       mode - cosmogenic atmospheric

       materials - ground water, ocean water, ice

       measures - isolation ages of deep and bottom waters, ice coring applications,

          hydrologic studies, ocean water circulation and mixing


    argon-40/argon-39 dating

       period - 2000 - 4600 m. bp

       mode - irradiated potassium-40 changes to argon-39 allowing exact ratio of

          potassium-40 to argon-40 which is related to time passed since formation      

       materials - volcanic rock, lunar meteorite impact melt clasts, tephra, pumice, tuff,

          sanidine, muscovite, K-feldspar, metamorphic rocks, lavas, basalts, tektites,

          andesites, mica, feldspar, hornblende, boninitic pillows, pyroxenes, biotite,

          plagioclase, adularia, gabbro, sericite, celadonite, meteorites, batholiths, dykes,

          schists, tourmaline, amphibole, detrital minerals, sediments, artifacts, rhyolite,

          alunite, natrojarosite

       measures - landscape evolution, uplift history, marine sequences, trap activity,

          orogenic development, exhumation, rock thermal histories, morphotectonics,

          artifact-quarry sourcing, effusive emplacement, age of the Earth, formation

          ages, metamorphism, crustal deformation, sedimentation, volcanic stratigraphy,

          cave formation

       synonyms - Ar thermochronometry, 40Ar/39Ar, 40Ar/39Ar geochronology,

          argon isotopic dating

       labs - 1) USGS 40-Ar/39-Ar laboratory - Menlo Park, CA

           2) Berkeley Geochronology Center


    argon isotopic dating - see argon-40/argon-39 dating


    Ar thermochronometry - see argon-40/argon-39


    artifact change - see seriation 


    artifact time marker

       period - 0 - 1.5 m. bp

       mode - an artifact type that was made by a particular culture during a limited time

          period, an indication of at least the relative time of the occupation

       materials - points, ceramics

       synonyms - index types


    association dating

       mode - relatively dated item associated with an absolutely dated item



       period - 0 - 25 m. bp

       mode - combines biostratigraphic and cyclostratigraphic chronologies

       materials - calcareous nannofossils, foraminiferas, microplankton, dinoflagellates

       measures - sediment emplacement



       period - 0 - 25 m. bp

       mode - cyclostratigraphic chronology

       synonyms - sonic astrochronology, gamma-ray astrochronology


    astronomical dating - see cyclostratigraphy


    astronomical forcing - see cyclostratigraphy


    astronomically tuned timescale - see Astronomical time scale


    Astronomical Polarity Time Scale (APTS)

       period - 0 - 25 m. bp

       mode - combines cyclostratigraphic and magnetostratigraphic dating


    Astronomical time scale (ATS)

       period - 0 - 146 m. bp, plus floating calibrations thru Triassic

       mode - cyclostratigraphic event chronology

       synonyms - astronomically tuned timescale, orbitally tuned time scale,

         orbital time scale, orbitally tuned geological timescale


    astronomy dating

       period - 0 - 4000 bp

       mode - astronomical consistencies change over time, compares current to past

          changes in the angle of the ecliptic, heliacal rising of Sirius, last sighting of the

          Lunar crescent each month, summer solstice

       materials - astronomical artifacts, stone circles, timber circles

       measures - building age


    authenticity dating

       mode - age related changes

       materials - fine art, documents, wood, ceramic, cast metal, artifacts

       measures - age, material availability


    Bayesian Chronological Modelling

       period – 0 – 4.6 b. bp

       mode - computer enhanced high precision dating using numerous low precision dates

          and combining diverse dating methods

       materials - teeth, tephra, sediments, fossils, artifacts, viruses, DNA

       measures - cultural chronologies, hominid timeframes, palaeoenvironmental sequences,

           age-at-death, predictive modelling, tephra deposition, phylogenetic branchings,

           divergence times, population sizes, linguistic phylogenies


    7Be dating

       period - 0 - 1 bp

       mode - atmospheric cosmogenic

       materials - sediments, surface waters, rock varnish

       measures - erosion rates, atmospheric and hydrologic processes


   10Be dating - see 10Be/9Be


   10Be/10B dating

       period - 4565 - 4571 m. bp

       mode – extinct radionuclide 10Be produced excess 10B

       materials - meteorites, CAIs, chondrites, hibonite

       measures - early solar system


   10Be/9Be dating

       period -  0 – 14 m. bp

       mode - atmospheric and surface cosmogenic

       materials - sediments, ice/rainwater, desert glass, manganese nodules, quartz,

          lacustrine diatomites, pelite, corals, alluvial fans, glacial ice, loess, chert,

          boulders, moraines deposits, rock surfaces, ice cores

       measures - histories of exposure, temporal variations in ice, geomorphism,

          deposition rates, growth rate of manganese nodule, faulting slip rates, transport,

          denudation rates, sedimentation rates, erosion rates, glacial histories,

          solar activity, paleoprecipitation, burial rates

       synonyms - beryllium dating, Al26/Be10 surface exposure dating,

          10Be dating

       labs – 1) LDEO Cosmogenic Nuclide Group

               2) Purdue Rare Isotope Measurement Laboratory


    benthic isotope stratigraphies

       mode - 18O and 13C stratigraphies

       materials - marine sediments

       measures - deep-water circulation


    beryllium dating - see 10Be/9Be



       period - 0 - 600 m. bp

       mode - chronologies based on variations in fossil assemblages

       materials - fossils, sediments

       measures - age transitions, extinction events, faunachrons


    biorange markers

       mode - biostratigraphic event markers with geographic range limitations



       period - 0 - 600 m. bp

       mode - index fossil markers

       materials - sediments, tephra, fossils, microfossils

       measures - terrestrial and marine palaeoenvironmental records, crustal dynamics,

          paleoclimate, range changes, evolution, extinctions, sedimentation rates

       synonyms - fossil reconstruction, index fossil dating, microfossil stratigraphy


    biozone dating

       period - 0 - 600 m. bp

       mode - index species first appearance designated with overlap

       materials - fossils, sediments

       measures - range, interval, assemblage, evolution, abundance

       synonyms - Oppel zone

       see also - ammonite-zone dating, conodont-zone dating, diatom-zone dating,

       dinoflagellate-zone dating, foraminifera-zone dating, fossil assemblages,

       fungal spore zone dating, fusulinid-zone dating, graptolite-zone dating,

       nannofossil biostratigraphy, nannofossil zone dating, Oppel zone, ostracode assemblages,

       palynology, palynomorph zone dating, palynostratigraphy, pollen profiles,

       radiolarian zone dating, trilobite-zone dating


    blue-light stimulated luminescence (BLSL) - see optically stimulated luminescence         


    body temperature time of death

       period - 0 - 20 hr

       mode - core temperature drops ~1.5 degree C/hr

       materials - human body

       measures - human time of death


    bomb-radiocarbon dating

       period - 0 - 60 bp

       mode - thermonuclear weapon production of 14C record

       materials - bone, teeth, organics, eye crystallin, lipids, hair, tooth enamel,

          tree rings, soils, corals

       measures - tooth formation age, age at death, date of death, year of birth,

          wine age, fossil fuel CO2 emissions, sediment accumulation rate,

          atmospheric patterns


    Bond events

       period - 0 - 11000 bp

       mode - 1500 year cyclic climatic events

       materials - ice-rafted debris

       measures - climate changes


    bone growth lines  

       mode - skeletal component with countable growth rings

       materials - vertebrae, gastric mills, otoliths, bones, ear bone

       measures - individual age of fish, finfish, dinosaurs, vertebrates, crocodilians,



    14C dating - see radiocarbon dating


    41Ca dating

       period - 50000 - 1 m. bp

       mode – surface cosmogenic

       materials - bone, limestone

       measures - early humans, rock exposure

       synonyms - radiocalcium dating


    41Ca/41K dating

       period - 4565 - 4571 m. bp

       mode – extinct radionuclide 41Ca produced excess 41K

       materials - meteorites, CAIs, hibonite, chondrites

       measures - early solar system, solar nebula


    calendar dating - see absolute dating


    calibrated relative dating

       mode - relative dates calibrated by chronometric dating


    carbon 14 dating - see radiocarbon dating


    carbon-isotope analysis

       period - 0 - 100 m. bp

       mode - stable isotope variations in 13C signal and 13C/12C ratios

       materials - carbonates, foraminiferas, nannofossils, organics, alkenones, peat,

          soils, waters, sediments

       measures - marine reservoir signal, paleodiet, taste, paleoclimate, ocean circulation

          changes, obliquity forcing, Suess effect, vegetation types

       labs – 1) University of Arkansas Stable Isotope Laboratory

            2) Stable isotope facility, University of Kansas


    cathodoluminescence - see optically stimulated luminescence


    cation ratio dating - see varnish stratigraphy


    cesium 137 dating – see 137Cs dating


    chemical isotope dating - see isotopic dating


    chemical transformations

       period -  0 - 6000 bp

       mode - molecular changes over time

       materials - food residues, chemical residues, ink, petroleum products

       measures - production age, cultural change, pollutant analysis, authenticity



       period - 0 - 4 b. bp

       mode - stratigraphic chemical variations

       materials - magma, tephra, sediments, turbidites, ice cores

       measures - tectonics, sediment age, barren sequences


    chlorine 36 dating - see 36Cl dating


    chlorine isotope dating - see 36Cl dating


    chronometric dating - see absolute dating



       period - 0 - 600 m. bp

       mode - provides a means of organizing strata into units based on their age relations.

          A chronostratigraphic unit is a body of rock established to serve as the material

          reference for all rocks formed during the same span of time. (NASC)

       measures - eonothem, erathem, system, series, stage, and chronozone


    36Cl dating

       period - 0 - 2 m. bp

       mode - cosmogenic exposure and nuclear industrial/weapon production

       materials - polar ice, ice, groundwater, soil, recent waters, sediments, lava flows,

          teeth, granite, alluvial fans, basalt, plagioclase

       measures - nuclear industry pollution, hydrogeology, rock slope failures,

          glacial advance, meteor impacts, atomic bomb dosimetry, erosion rates,

          fault dynamics

       synonyms - radiochlorine, chlorine isotope dating, chlorine 36 dating

       labs - LDEO Cosmogenic Nuclide Group


    climatic time series - see cyclostratigraphy



       period - 0 - 4 b. bp

       mode - climate influenced traces left in the geologic column

       materials - sedimentary rock

       measures - glacial events, climatic phases, global climatostratigraphic scale


    36Cl/36S dating

      period - 4565 - 4571 m. bp

      mode – extinct radionuclide 36Cl produced excess 36S

      materials - meteorites, CAIs, chondrites, wadalite, sodalite, chondrules

      measures - early solar system


    conodont zone dating

       period – 250 - 600 m. bp

       mode – type specific chronostratigraphic index markers

       materials - marine sediments, conodont faunas

       measures - paleoecology, deposit age


    content comparison - see image dating


    contextual placement - see image dating


    coral dating - see uranium/thorium dating


    coral reef dating

       period - 0 - 2 m. bp

       mode - reef expansion/repression

       materials - coral reefs

       measures - major meltwater pulses, glacial cycles, sea levels, seafloor tectonics,

          uplift, sinkage


    coral ring dating

       mode - annual rings or bands

       materials - coral, ritual coral sites and structures

       measures - climate change, artifact age


    corrosion age models

       materials - metals, underground storage tanks, artifacts

       measures - age


    cosmic ray dating

       period - 4565 - 4571 m. bp

       mode - direct formation of fission tracks by cosmic rays

       materials - lunar samples, meteorites

       measures - crystallization age, early solar system

       synonyms - fission track dating


    cosmic ray exposure age - see cosmogenic dating



       period - 4500 - 4600 m. bp

       materials - meteorites, lunar samples

       measures - extinct radionuclides, early solar system

       labs – 1) Center for Space and Planetary Sciences, University of Arkansas

             2) Center for Isotope Cosmochemistry and Geochronology



       period - 4500 - 4600 m. bp

       materials - lunar samples, meteorites

       measures - early solar system, early universe, universe growth


    cosmogenic dating

       period - 0 - 10 m. bp

       mode - cosmic rays surface/atmospheric exposure isotope production

       materials - meteorites, corals, terrestrial rocks, plagioclase, olivine, sediments,

          teeth, lava flows and dams, moraines, alluvial-fan surfaces, desert

          pavements, hillslope deposits, debris flows, fault scarps, stone tools,

          petroglyphs, geoglyphs

       measures - erosion rates, landforms, uplift rates, denudation, geomorphism,

          exhumation rates, surface exposure ages, impact crater age, paleoaltimetry,

          climate change, deglaciation chronologies

       synonyms - cosmogenic isotope dating, cosmogenic nuclide dating,

          cosmic ray exposure age, surface-exposure dating

       labs – 1) LDEO Cosmogenic Nuclide Group

             2) Cosmogenic Nuclide Dating Laboratory – Stanford University


    cosmogenic isotope dating - see cosmogenic dating


    cosmogenic nuclide dating - see cosmogenic dating


    cosmological time scale

       period - 0 - 13.7 b. bp

       measures - evolution of universe, galaxies, solar systems



       period - 0 - 5700 m. bp

       mode - known dated artifact may transfer date to related structures

       measures - artifacts, fossils, tree-rings, geologic column


    137Cs dating

       period -  0 - 60 bp

       mode - nuclear fallout markers

       materials - lake sediments, sediments, soils

       measures - sediment accumulation rates and patterns, soil erosion, radioactive fallout

       synonyms - cesium137 dating



    cultural affiliation dating

       period - 0 - 1 m. bp

       mode - cultural artifact comparison and identification

       materials - human artifacts, DNA, language

       measures - cultures, migrations, invasions, early human


    cyclicity - see cyclostratigraphy



       period - 0-500 m. bp

       mode - periodicities of precession, obliquity, and eccentricity of the Earth's orbit

          produce cyclic changes in climate remarked in sediments

       materials - sediments, clays, carbonates, sapropels, CaCO, limestones, foraminifera,

          plankton, dinoflagellates, tephra, nannofossils, biogenic silica, dust, organic carbon

       measures - color reflectance, paleoclimate, paleoceanography, drought frequency,

          seafloor spreading rate, density, insolation, dust content, magnetic susceptibility,

          TOC, grain size change, light reflectance, sedimentation rates, environmental

           reconstruction, clay mineralogy, geochemistry, magnetic-susceptibility,

           photoelectric factor, total gamma-ray

       synonyms - orbital forcing, climatic time series, solar forcing, orbital tuning,

          astronomical dating, orbitally tuned cyclostratigraphy, orbital stratigraphy,

          orbital dating, orbitally tuned stratigraphy, Milankovitch cycles, cyclicity


    Dansgaard-Oeschger Events

       period - 200 - 80000 bp

       mode - cyclic rapid cold climatic events

       materials - ice cores, marine sediments, lake sediments, pollen, foraminifera,


       measures - warming and cooling periods, Heinrich events, sea level changes,

          climate modeling



       period - 0 – 13.7 b. bp

       mode - determination of a time, date, or range of dates relevant to an occurence


    decay age estimation

       materials - bodies, fabrics

       measures - time of death


    deglaciation chronology

       period - 9000 - 14000 bp

       mode - ice-front accumulation markers

       materials - glacial deposits, moraines

       measures - uplift rates, glacial and sea level fluctuations, paleoclimate events,

           exposure age


    dendroarchaeology - see dendrochronology



       period - 0-12000 bp, floating sequences back into the Cretaceous Period

       mode - annual growth rings are produced in the xylem of trees

       materials - logs, trees, woodwork, beams

       measure - rainfall, drought, heat waves, cold spells, climate, ecosystem health,

          pollution of air, soil, or water, volcanic and meteoric impact events, forest

          histories, solar sunspot activity, authenticity, architecture, frost rings, fires,

          environmental history, historic and prehistoric structures, monsoon histories,

          carbon sequestration, insect and disease stressors, radiocarbon calibration,

          local fossil fuel CO2 emissions, felling dates

       synonyms - tree ring analysis, tree ring dating, dendroarchaeology

       labs - 1) Tree-Ring Laboratory Department of Geosciences - University of Arkansas

            2) Missouri Tree-Ring Laboratory Department of Forestry, University of Missouri-

                  Columbia, Columbia, MO

            3) B.E.T.R. Laboratory, Biogeography, Environment, and Tree-Ring Laboratory at

                  Austin Peay State University, Clarksville, TN

            4) Indiana State University Biogeography and Dendrochronology Laboratory

            5) University of Minnesota Center for Dendrochronology

            6) Arizona Geochronology Center – University of Arizona



       period - 0-12000 bp

       mode - annual growth rings show variations in climate

       materials - logs, trees

       measures - rainfall, drought, heat waves, cold spells, frost rings, climate change,

           monsoon histories, climate reconstructions

       labs - 1) Tree-Ring Laboratory – University of Arkansas



       period - 0-12000 bp

       mode - annual growth rings show ecological change

       materials - logs, trees

       measures - ecosystem health, pollution of air, soil, or water, forest histories, fires,

           environmental history, carbon sequestration, insect and disease stressors,

           forest dynamics, landscape change

       labs - 1) University of Minnesota Dendroecology Laboratory



       period - 0-12000 bp

       mode - annual growth rings show land-surface change

       materials - exposed roots, logs, trees

       measures - erosion rates, first year of root exposure, debris flows, avalanches


    dentition age analysis

       period - 0 - 70 yrs

       mode - physical characteristics, normal development and eruption timing

       materials - teeth, jaw, dentin

       measure - tooth wear, mineral density, age at death


    derivative dating

       mode - technique dependant upon local environment thus requiring prior absolute

          fixing of local environment variable before application on its own


    desert varnish - see varnish stratigraphy


    detrital chronometry - see detrital thermochronometry


    detrital thermochronology – see detrital thermochronometry


    detrital thermochronometry

       period - 1 - 40 m. bp

       mode - closure temperature referents

       materials - sediments, zircon, apatite

       measures - basin sediments, erosion, denudation rates, exhumation,

          sediment provenance, landscape evolution, paleorelief, depositional age,

          orogenic exhumation, basin provenance

       synonym - detrital thermochronology, detrital chronometry


    deuterium analysis

       period - 0 - 2000 bp

       materials - bristlecones

       measures - climate change, water cycle


    diatom zone dating

       period - 0 - 65 m. bp

       mode – type specific chronostratigraphic index markers

       materials - manganese nodules, freshwater and marine muds,

          silica enriched sediments

       measures - palaeoenvironmental reconstructions, palaeoecologies,

          paleoclimate reconstructions, lake level changes, paleolimnology


    differential weathering

        mode - relative weathering indicates age or priority

        materials - rock

        measures - rock art


    dinoflagellate zone dating

        period - 0 - 260 m. bp

        mode – type specific chronostratigraphic index markers

        materials - dinoflagellates, marine sediments

        measures - palaeoenvironmental reconstructions, palaeoecologies,

          paleoclimate reconstructions


    direct dating

       mode - dating method which provides a specific date with no other referent necessary


    DNA analysis

       period - 0 - 2.8 b. bp

       mode - DNA sequence comparison

       materials - tissue samples, eggshells, bones, mtDNA, teeth, collagen, hair, bacteria,

          fungi, yeasts, Neanderthal genome, genes, genetic sequences

       measures - kinship, authenticity, universal ancestor, disease, parasitism, gene

          appearance, lineages, genealogical structure, population size, mutation rates

          and processes, effects of diets, origins and spread of agriculture, animal and

          plant domestication, migrations, genetic divergence, leaf-ages,

          evolutionary rate, population bottlenecks, climate change, forensic matches

       synonyms - gene mapping, molecular clock, genetic dating, phylogenetic comparison

       labs – 1)Molecular Anthropology Laboratory – University of Oklahoma


    document dating

       period - 0 - 5000 bp

       materials - clay, paper, papyrus

       measures - forensics, authenticity


    Early Solar System timescale

       period - 4565 - 4571 m. bp


    ear wax age

       mode - number of layers of ear wax in inner ear indicates age

       materials - ear wax

       measures - whales, blue whales, fin whales



       mode - faunal assemblage markers of unusual species or unusual populations of


       materials - fossils

       measures - stratigraphic succession, ecological change, transgressions, regressions


    eggshell dating - see amino acid racemization


    electron paramagnetic resonance - see electron spin resonance


    electron spin resonance

       period - 500 - 500 million bp

       mode - radiogenic accumulation of electrons in crystalline lattice whose magnetic

          resonance strength reflects time since formation, nondestructive

       materials - coral, bones, teeth, shell, calcium carbonate in limestone, quartz, flint,

          sediments, minerals, meteorites, calcite, tooth enamel, volcanic ash, feldspar, pumice,

          volcanic quartz, granitic quartz, tephra, loess

       measures - mineralization, sedimentation, last heating of minerals, meteorite strikes,

          earthquake activity, human settlement history, alluvial deposit history,

          sediment provenance, granite age, age of crystallization

       synonyms - ESR, electron paramagnetic resonance (EPR)

       labs - 1) Archaeometry and Geochronology Laboratory, McMaster University


    entomological time of death

       mode - insect life cycle changes on recently found cadavers

       materials - insects, flies, blowflies

       measures - time of death


    environmental archaeology – see zooarchaeology, archaeobotany, pedoarchaeology


    environmental release dating

       materials - pollutants, soil, groundwater

       measures - degradation, tree ring uptake


    ESR - see electron spin resonance


    event chronology - see event stratigraphy


    event stratigraphy

       period - 0 - 4 b. bp

       mode - dated markers

       materials - lake sediments, loess, tephras, marine sediments, trees,

          coral reefs, fossils

       measures - floods, volcanics, local, regional and global, Heinrich events,

          climate events, droughts, solar fluctuations, nova receptions, glaciations,

          major population upheavals, asteroid collisions, extinctions, habitat changes,

          meltwater pulse, faunal replacements, Dansgaard-Oeschger events,

          Bond events, meteor impacts

       synonyms - natural catastrophe stratigraphy, global climatic events,

          isotopic event stratigraphy

       see also - age equivalent stratigraphic markers, biorange markers, Bond events,

          Dansgaard-Oeschger Events, Heinrich events, isotopic event stratigraphy,

          natural catastrophe stratigraphy, sequence stratigraphy


    excess (226)Ra - see 238U-230Th-226Ra


    extinct radioisotope chronometry

       period - 4565 - 4571 m. bp

       mode - products of nova generated short-lived radionuclides indicate event


       materials - meteorites, Ca-Al-rich inclusions (CAIs), chondrules

       measures - early solar system processes, planetesimal formation,

          planetary melting, planetary mantle and core formation


    Extinct Radionuclide Timescale

       period - 4565 - 4571 m. bp


    60Fe/60Ni dating

       period - 4565 - 4571 m. bp

       mode – extinct 60Fe produced an excess of 60Ni

       materials - meteorites, eucrites, pyroxene, chondrules, troilite, magnetite,

          achondrites, chondrites, sulfides, olivine, enstatite, presolar grains

       measures – early solar system processes, Vesta, presolar processes


    fission track dating

       period - 0 to 6 b. bp

       mode - radiogenic damage trails produced in glassy materials, number reflects the

          time passed since last exposed to high temperatures

       materials - apatite, zircon, sphene, titanite, biotite, mica, barite, epidote, garnet,

          natural glasses, obsidian, pitchstone, tephras, man-made ceramics, meteorites,

          lunar rocks, tektites, barren sequences, red beds

       measure - sea floor spreading rates, volcanic arc motion, denudation history,

          fault studies, thermal history, last firing, rates of uplift and exhumation,

          sediment sourcing, depositional histories

       synonyms - fission track thermochronology, fission track geochronology,

          low-temperature thermochronometry, cosmic ray dating

       labs - Fission Track Thermochronology Laboratory, University of Kansas


    fission track geochronology - see geochronology, fission track dating


    fission track thermochronology - see fission track dating, thermochronometry


    fluorine analysis

       period - 100 bp - 1 m. bp

       mode - buried bone fluorapatite increase

       materials - bones, teeth, antlers, middens

       measures - contemporaneity


    fluorine, uranium and nitrogen test - see U-Fl-N dating


    foraminifera zone dating

       period - 0 - 360 m. bp

       mode – type specific horizon markers

       materials - foraminifera, sediments, tuffaceous sediments

       measures - climate changes, salinity, Heinrich events, palaeobiogeography,

          upper ocean temperatures, oceanic productivity, oceanic circulation patterns,

          carbonate dissolution, palaeoecology, oil exploration, sedimentation rates,

          biostratigraphy, paleoceanography, oxygenation, palaeoenvironment


    forensic dating

       materials - teeth, bones, dentine, artifacts, fibrin, blood cells

       measures - age estimation, time of death, artifact authenticity, skeletal development


    fossil assemblages

       period - 0 - 570 m. bp

       mode - group-specific chronostratigraphic index markers

       materials - fossils, sediments, insects, microfossils

       measures - period, stage, extinction events, water depth, depositional environment,

          sea-level change, biota associations, paleoecologies, palaeoenvironments


    fossil reconstruction - see biostratigraphy


    fungal spore zone dating

       period - 0 - 400 m. bp

       mode – type specific chronostratigraphic index markers

       materials - fungal spores, terrestrial sediments

       measures - dryness indicator, fire indicator

       synonyms  - palynomorph zone dating


    fusulinid zone dating

       period - 250 - 360 m. bp

       mode – type specific horizon markers

       materials - fusulinids, marine sediments

       measures - age


    gamma-ray astrochronology - see astrochronology


    gamma ray attenuation density

       period - 0 - 6 m. bp

       mode - fall of induced or natural high-frequency radiation

       materials - marine sediments, sapropels

       measures - insolation record, paleoclimate, blazar age,

             proxy for orbital precession and obliquity


    gene mapping - see DNA analysis


    genetic dating - see DNA analysis



       mode - geological archaeological artifact analysis

       materials - stone tools, petroglyphs, geoglyphs, chamber tombs

       labs – 1) University of Kansas Biodiversity Institute

             2) AQRL - Indiana State University


    geochemical dating

       period - 0 - 4 b. bp

       mode - geochemical variation and event markers

       materials - tephra, organic carbon, rock, soil, water, meteorites, lunar samples,

           biostratigraphically barren sequences, flow deposits, obsidian, cryptotephras

       measures - early life, orbital forcing, oceanic oxygenation, early solar system,

           isotopic composition, igneous differentiation processes, sourcing,

           volcanism, ore deposition, climate change, lake level change,

           major, trace, and rare-earth elements, plate motion

       synonyms - amino acid geochemistry, aqueous geochemistry, isotope geochemistry,

            isotope geology, isotopic dating, lead-lead isotope geochemistry,


       labs - 1) Aqueous geochemistry laboratory University of Missouri-Columbia

            2) Organic Geochemistry Lab, University of Missouri-Columbia

            3) KU Geology Department, University of Kansas



       period – 0 - 4 b. bp

       mode - A geochronologic unit is a division of time distinguished on the basis of the

          rock record preserved in a chronostratigraphic unit (NASC)

       measures - eon, era, period, epoch, age, and chron

       synonyms - noble gas geochronology, fission track geochronology,

          40Ar/39Ar geochronology, 40K/40Ar geochronology, U–Pb geochronology,

          plutonic geochronology, uranium series geochronology, 210Pb geochronology,

          radiocarbon geochronology, luminescence geochronology,

          U/ Pb zircon geochronology, amino acid geochronology

       labs – 1) Department of Geology, University of Kansas

            2) Arizona Geochronology Center

            3) Berkeley Geochronology Center

            4) Center for Archaeometry and Geochronology, University of Tennessee

      see also - amino acid geochronology, 40Ar/39Ar geochronology, fission track geochronology,

        K–Ar geochronology, luminescence geochronology, noble gas geochronology,

        210Pb geochronology, plutonic geochronology, radiocarbon geochronology,

        radioisotopic geochronology, 87Sr/86Sr geochronology, U–Pb geochronology,

        U/ Pb zircon geochronology, uranium series geochronology, U-Th-Pb geochronology



       period - 0-4.6 b. bp

       mode - A geochronometric (or chronometric) unit is an isochronous direct division of

          geologic time expressed in years, has no material referent. (NASC)


    geologic chronology - see geochronology


    geological time scale

       period - 0 - 4 b. bp

       synonyms - Standard Global Chronostratigraphic Scale, stratigraphic time-scale



       period - 0 - 4.57 b. bp

       mode - study of earth change


    geomagnetic polarity time scale (GPTS)

       period - 0 - 155 m. bp

       synonyms - magnetic polarity time scale, geomagnetic reversal time scale,

          seafloor anomaly timescale


    geomagnetic reversal time scale - see geomagnetic polarity time scale


    geomagnetic time scale

       period - 0 - 3.5 b. bp



       period - 0 - 4 b. bp

       mode - landform change analysis

       materials - soils, sediments

       measures - paleoclimates, glaciations, tectonics, landforms, settlement responses,

          environmental changes, periglacial deposits, volcanism, erosion, wind and water

          effects, mass wasting, weathering, desertification, paleorelief, shorelines,

          human impact, vegetation change

       synonyms - glacial geomorphology, glacial geology, tectonic geomorphology,

          morphostratigraphy, denudation chronology, land-uplift chronology,

          paleotopography, soil geomorphology, aeolian geomorphology

       see also - aeolian geomorphology, dendrogeomorphology, glacial geology, glacial geomorphology,

        land-uplift chronology, soil geomorphology, tectonic geomorphology


    geothermometry - see argon-40/argon-39


    GISP2 ice core - see ice core dating


    GISP2 isotope record - see ice core dating


    glacial geology - see geomorphology


    glacial geomorphology - see geomorphology


    global climatic events

       period - 0 - 4 b. bp

       mode - climatostratigraphic proxies

       materials - sediments

       measures - trap emissions, temperature extremes, solar flux extremes, ice ages,

          meltwater pulses, forest motion, precession, obliquity, eccentricity, supervolcanoes,

          desert boundary motion, Bond events, Heinrich events

       synonyms - event stratigraphy


    global climatostratigraphic scale - see climatostratigraphy


    graptolite zone dating

       period - 420 - 500 m. bp

       mode – type specific horizon markers

       materials - graptolites, marine sediments

       measures - age


    GRIP ice core - see ice core dating


    growth ring age

       mode - skeletal component with countable growth rings and environmental variation

       materials - ear wax, vertebrae, shell, eyestalks, gastric mills, otoliths, scales, bones,

          fin rays, spines, inner ear bone, wood, arctic algae deposits, coral

          sclerosponge skeletons

       measures - individual age of lobsters, crabs, shrimp, fish, scallop, clams, trees, shellfish,

          crustaceans, finfish, invertebrates, whales, dinosaurs, vertebrates, crocodilians,

          molluscs, sharks, paleoenvironment


    GRTS - see geomagnetic reversal time scale, paleomagnetic dating


    3H dating - see tritium analysis


    hafnium-tungsten dating

       period - 4.52 - 4.57 b. bp

       mode - extinct Hf182 produced excess W182

       materials - lunar rocks, Martian meteorites, asteroids, CAIs, meteorites,

          chondrules, angrites, chondrites

       measures - core formation, early planetary evolution, early solar system,

          accretion, moon formation

       synonyms - Hf-W dating, Hf–W chronometry


    He dating - see (U-Th)/He dating, 4He/3He thermochronometry


    3He dating

       period - 0 - 1 m. bp

       mode - surface cosmogenic nuclide

       materials - surface rock, olivine, basalt

       measures - erosion rates, uplift rates, fault motion

       labs - LDEO Cosmogenic Nuclide Group


    4He/3He thermochronometry

       period - 0 - 2 m. bp

       mode - U/Th production of 4He compared to artificial 3He

       materials – olivine, basalt, apatite, goethite, meteorites

       measures - fault motion, erosion, denudation, topographic changes,

          thermal histories

       synonyms - thermochronometry, radiogenic helium, helium dating,

          helium-helium thermochronometry, helium thermochronometry,

          low-temperature thermochronometry


    Heinrich events

       period - 12000 - 60000 bp

       mode – short warming events produce markers of soil and rock from iceberg melts

       materials - marine sediments, ice rafted debris, ice cores

       measures - stadials and cold rebounds, moraine sequences, climatic events,

          oceanic salinity, sea level, glacial climate


    helium dating - see (U-Th)/He dating


    helium-helium thermochronometry - see 4He/3He thermochronometry


    helium-lead dating

       period - 1 m. – 500 m. bp

       mode - combined (U-Th)/Pb and (U-Th)/He methods

       materials - zircon, sediments

       measures – crystallization and cooling ages

       synonyms - Pb/He dating


    helium thermochronometry - see 4He/3He thermochronometry


    Hf–W chronometry - see hafnium-tungsten dating


    Hf-W dating - see hafnium-tungsten dating


    high-temperature thermochronology

       mode - high closure temperature dating methods

       materials - zircon

       measures - exhumation, denudation


    hydration profiles

       mode - exposed surfaces of silicates take up water from the atmosphere forming a

          layer that deepens over time

       materials - obsidian, quartz

       synonyms - hydrogen depth profile, obsidian hydration dating, quartz hydration



    hydrogen depth profile - see hydration profiles


    hydrogen isotope analysis

       mode - isotopic variation

       materials - water

       measures - hydrothermal alteration, ore deposition

       labs - 1) Stable Isotope Laboratory - University of Arkansas


    ice core dating

       period - 0 - 120000 bp

       mode - annually laminated coring and analysis

       materials - tephras, sediments, cryptotephra, ice, glacial ice, air bubbles

       measures - paleoclimate, 18O/16O, isotopic events, stadials, cold events, Dansgaard-

           Oeschger cycles, Heinrich events, solar activity, cosmic-ray flux, CO2 cycle,

           environmental changes, oxygen isotopes, palaeotemperatures, volcanic activity,

           chemical traces of eruptions, volcanism, prevailing wind patterns, climatic forcing,

           meltwater spikes, ice-flow models, local climate record, interstadial correlations,

           warming events, acid rain spikes

       synonyms - GISP2 ice core, GRIP ice core, GISP2 isotope record


    ice flow models

       period - 0- 7500 bp

       materials - tephra layers, ice


    image dating

       mode - comparisons to datable material

       measures - rock art, artifacts

       synonyms - content comparison, contextual placement, style, superimposition


    index fossils

       period - 0- 540 m. bp

       mode - short lived, widespread fossil types representative of a particular strata or

          time period


    index types - see artifact time marker


    indirect dating - see relative dating


    infrared stimulated luminescence

       mode - based on the release of electrons trapped in crystal defects

       materials - quartz, polymineral fine grains, sands, aeolian sand, alluvial fan deposits,

          desert sands, potassium feldspars, alluvial sediments, loess, sediments, dune sands,

          sediment cores, feldspar, waterlain sediments, high arctic marine sediments,

          plagioclase, organic-rich sediments, reworked silty sediments, fault-related

          sediments, detrital feldspars, sodium feldspars, lake-sediments

       measure - palaeolimnological record, earthquake recurrence, fault movements,

          catchment disturbance

       synonyms - luminescence, optically stimulated luminescence


    ink dating

       mode - chemical degradations of volatiles

       materials - ink, paper, papyrus

       measures – authenticity

       synonyms - micro-Raman spectroscopy


    inter-site patterning

       mode - dated artifact comparisons

       materials - rock art, artifacts

       measures - rock art age, cultures


    invertebrate paleontology

       period - 0 - 600 m. bp

       mode - invertebrate analysis

       labs - University of Kansas Biodiversity Institute


    iodine-129 dating

       mode - surface cosmogenic and U238 decay

       materials - granite

       measures - hydrogeology


    iodine-xenon dating

       period – 4.52 – 4.57 b. bp

       mode - extinct 129I produced excess 129Xe

       materials - halite, Shallowater meteorites, enstatites, feldspar, plagioclase, lunar rocks,

          chondrites, magnetite, CAIs, phosphates, meteorites, silicate, troilite, chondrules,

       measures - meteorite formation, early solar system events and processes,

          nebular events, parent–body processes

       synonyms - I-Pu-Xe dating


    I-Pu-Xe dating – see iodine-xenon dating


    isotope geochemistry  

       period - 0 - 5.7 b. bp

       mode - geological studies using stable isotopes and radioisotopes

       materials - rock, sediment, water, minerals, meteorites

       measures - geological processes, agricultural processes, orogenesis,

          early solar system, groundwater, pollution, nuclear fallout, sourcing

       synonyms - isotope geology

       labs - 1) Isotope Laboratory of the Department of Geosciences and Arkansas Center

                    for Space and Planetary Sciences at the University of Arkansas, Fayetteville

            2) Isotope Geochemistry Laboratory, University of Kansas

            3) Purdue Rare Isotope Measurement Laboratory


    isotope geology - see isotope geochemistry


    isotope stage - see isotopic time scale


    isotope stratigraphy - see isotopic dating


    isotopic dating - see stable isotope analysis, isotopic geochemistry

         synonyms - geochemical dating, chemical isotope dating


    isotopic event stratigraphy - see event stratigraphy


    isotopic time scale

         period - 0 - 25 m. bp

         synonyms - isotope stage


    isotopic tracing

       mode - isotopic signatures pass from local rock into local grown plants and animals

          and its manufactures

       materials - clay artifacts, fossils, nitrates, ammunition, pollutants, sediments, tephra,

          magma, water

       measures - forensic sourcing, migration patterns, trade, pollution, sediment sourcing,

          biological sourcing, nuclear forensics, environmental monitoring, hydrology


    K-Ar dating - see potassium-argon dating


    K–Ar geochronology - see geochronology, potassium-argon dating


    K-Ca dating

       mode - radioisotope mother-daughter with stable Ca isotope comparison

       materials - mica, evaporites, pegmatite, sylvite

       measures - age


    40K-40Ca ‘double-plus’ dating

       mode - radioisotope mother-daughter two-positive ion separation

       materials - muscovite, alkali feldspar

       measures - age



       period - 0 - 2 m.bp

       mode – atmospheric cosmogenic

       materials - groundwater, ice cores, air bubbles

       measures - atmospheric abundance, ice age climate

       synonyms - krypton-81


    Kr-Kr exposure age

       mode - cosmic ray surface spallation

       materials - lunar rock

       measures - lunar crater age


    krypton-81 - see 81Kr


    lacustrine sediment cores - see lake sediment successions


    lake level analysis

       period - 0 - 30000 bp

       mode - high and low water stands

       materials - sediments, lacustrine deposits, alluvial gravels, sand wedges

       measures - paleoclimate, drainage effects, paleogeography, climate changes

       synonyms - paleoshoreline analysis


    lake sediment successions

       period - 0 - 40000 bp

       materials - lake sediments, pollen, aquatic fauna and flora

       measures - glacial activity, paleoclimate, salinity, regional vegetational history,


       synonyms – paleolimnology


    Lamendin age

       mode - dental characteristics

       measures - human age at death


    laminated sediments - see varve chronology


    L-amino/D-amino ratio - see amino acid racemization


    land-uplift chronology - see geomorphology


    lead isotopic ages- see U/Pb dating, 207Pb/206Pb, 210Pb


    lead-lead dating - see U/Pb dating


    lead-lead isotope geochemistry

       materials - igneous materials, sediments, pollutants, ammunition, bone, teeth

       measures - sourcing of igneous materials, sediments, pollution, ammunition,




       period - 10 - 3000 bp

       mode - lichen growth depth and extent, thallus grows systematically in proportion to


       materials - lichen

       measures - snow-avalanche activity, time of surface stabilization, moraines,

          glaciation, glacier fluctuations, glacier advances, petroglyphs


    lithodemic unit

       period - 0 - 4.4 b. bp

       mode - defined body of predominantly intrusive, highly deformed, and/or highly

          metamorphosed rock, distinguished and delimited on the basis of rock

          characteristics, generally does not conform to the Law of Superposition, with

          mappability (NASC)

       materials - intrusives, gneiss, schist, plutonics, extrusives, granodiorite, diorite,

          dikes, syenite, gabbro, granite, sills

       measures - terranes in which rocks generally lack primary stratification, lithology, or

          local and regional structure, economic resources, geologic history



       period - 0 - 4.4 b. bp

       mode - unit is a stratum or body of strata, generally but not invariably layered, generally

          but not invariably tabular, which conforms to the Law of Superposition and is

          distinguished and delimited on the basis of lithic characteristics and stratigraphic

          position (NASC)

       materials - sedimentary, extrusive igneous, metasedimentary, or metavolcanic strata,

          clay, gravel, till, and other unconsolidated deposits

       measures - supergroups, groups, formations, members, beds, and flows



       mode - tephra sandwiched between two master tephras is afforded its age by

          interpolating the thicknesses of loess between them

       materials - loess, tephra

       measures - age


    low-temperature thermochronometry - see (U-Th)/He dating, thermochronometry,

            apatite fission track dating, 4He/3He thermochronometry

       mode - isotopic systems with low temperature closure

       materials - apatite, meteorites, sediments

       measures - exhumation, magmatism, landscape evolution, tectonics, geodynamics,

          surface processes, erosion rates



       period - 5 m. - 500 m. bp

       mode - radiochronological parent-daughter relationship

       materials - garnet, eclogites

       measures - high-pressure metamorphism, deformation


    luminescence dating - see infrared stimulated luminescence, optical dating, TL,

       optically stimulated luminescence, OSL, pulsed photostimulated luminescence,

       radioluminescence, thermoluminescence


    luminescence geochronology - see geochronology


    lunar geologic timescale

       period - 0 - 4600 m. bp


    macrofossil stratigraphy - see biostratigraphy


    magnetic anomaly time scale

       period - 0 - 71 m. bp


    magnetic lead dating

       period - 0 - 2500 bp

       mode - lead corrosion effect on superconductivity reflects age

       materials - lead artifacts

       measures - age


    magnetic polarity time scale - see geomagnetic polarity time scale


    magnetic reversal stratigraphy - see magnetostratigraphy


    magnetic stratigraphy - see magnetostratigraphy



       period - 0 - 500 m. bp

       mode - combines magnetostratigraphy and biostratigraphy

       materials - marine and continental sediments, foraminifera

       measures - age



       period - 0 - 500 m. bp

       mode - combines magnetostratigraphy and cyclostratigraphy

       materials - marine and continental sediments

       measures - age

       synonyms - secular variation magnetostratigraphy



       period - 0 - 500 m. bp

       mode - magnetic reversals tied to the stratigraphic column

       materials - sediments, tephra, sapropels, lava flows, fossils

       measures - coastal plain, terrestrial and marine palaeoenvironmental records,

          traps, exhumation, oceanic productivity

       synonyms - magnetic reversal stratigraphy, magnetic stratigraphy


    manganese/chromium dating – see Mn/Cr dating


    marine isotope stage (MIS)

       period - 0 - 3 m. bp

       mode - stable isotope variation

       materials - marine sediments, plankton,

       measures - temperatures, meltwater spikes, Heinrich events, transgressions,

          Dansgaard-Oeschger cycles, climate change, glaciations

       synonyms - marine oxygen isotope stage, marine stable isotope records,

          oxygen isotope stage, isotope stage


    marine oxygen isotope stage - see marine isotope stage


    marine stable isotope records - see marine isotope stage


    Martian geologic timescale

       period - 0 - 4600 m. bp


    meltwater pulse

       mode - occurences of rapid sea level rise

       materials - coral reefs

       measures - paleoclimate, glacial extent, coral reef limiter, thermohaline circulation


    microfossil stratigraphy - see biostratigraphy


    micropalaeontology - see paleontology


    migration analysis

       mode - various

       measures - settlement, resettlement, expansions, arrivals, climate change, extinctions,

          environmental reconstructions, erosion


    Milankovitch cycles - see cyclostratigraphy


    53Mn/53Cr dating

       period - 4565 m. - 4571 m. bp

       mode - extinct radionuclide 53Mn produced excess 53Cr

       materials - meteorites, chondrites, angrites, pyroxenes, olivine,  carbonates, CAIs,

         eucrites, chondrules, fayalite, achondrites, enstatites, sulfides, diogenites, pallasites,


       measures - early solar system events, earth surface processes, nebular processes,

          early planetary evolution, asteroid belt


    molecular anthropology

       materials - DNA

       measures - gene change

       synonyms - anthropological genetics

       labs - 1) University of Oklahoma's Molecular Anthropology Laboratories


    molecular archaeology - see molecular dating


    molecular clock – see DNA analysis


    molecular dating   

       period - 0 - 40000 bp

       mode - residue degradation consistencies

       materials - wood, starch, blood

       measures - food residues, sourcing, forensic timing

       synonyms - molecular archaeology, nano archaeology


    morphostratigraphy - see geomorphology


    nannofossil biostratigraphy - see nannofossil zone dating


    nannofossil zone dating

       period - 0 - 210 m. bp

       mode - genera-specific horizon markers

       materials - tephra, bentonite, marine sediments, calcareous nannoplankton,

          nannofossil placoliths

       measures - traps, carbonate productivity, 41-k.y. cycles, paleoecology

       synonyms - nannofossil biostratigraphy


    nano archaeology - see molecular dating


    natural catastrophe stratigraphy - see event stratigraphy


    Nd-Nd ratios

       mode -  Nd-Nd isotopic ratios of local rock is same as that grown on or made of it

       materials - organics, products

       measures - sourcing, migration patterns, trade, forensics


    Ne-21 dating

       mode - cosmogenic surface nuclide

       materials - quartz, meteorites

       measures - denudation, early solar system


    niobium–zirconium chronometry

       period - 4565 m. - 4571 m. bp

       mode - extinct radionuclide 92Nb produced excess 92Zr

       materials - chondrites, mesosiderites, rutile

       measures - early solar system, early planetary evolution


    nitrogen analysis

       mode - nitrogen decreases through the decay of bone protein

       materials - bone, burials

       measures - later mound intrusive burials


    nitrogen isotope analysis

       mode – stable isotopic variation

       materials - sediments, basalts, meteorites, soils, bone, teeth, amino acids, food remains,

          stomach contents

       measures - paleodiet, paleo-economy, reservoir effect, decomposition

       labs - 1) Stable Isotope Laboratory - University of Arkansas


    noble gas geochronology - see geochronology

       period - 0 - 4.6 b. bp

       materials - iodine, xenon, neon, krypton, argon, helium

       measures - early solar system, geology, atmospherics


    noble-gas thermochronology - see noble-gas thermochronometry


    noble-gas thermochronometry – see thermochronometry

       labs – 1)Berkeley Geochronology Center



       period - 4.5 - 13.7 b. bp

       mode - stellar radioactive decay chronometers

       materials - 232Th/238U, Th/Eu ratios

       measures - galaxy formation, element formation

       synonyms - Th/Eu nucleocosmochronology


    numerical dating - see absolute dating



       mode - coin date associations

       materials – coins


    18O stratigraphy - see oxygen isotope record


    obsidian diffusion dating - see obsidian hydration dating


    obsidian hydration dating

       period - 500 - 100000 bp

       mode - surface water absorption depth reflects time since exposed

       materials - obsidian artifacts, flakes, volcanic glass, glass, basaltic glass,

          glasses used for encasing waste, industrial glasses

       measures - seismic history, temperature, humidity, paleoenvironment,


       synonyms - obsidian diffusion dating, hydration profiles

       labs - 1) Archaeometry Laboratory - University of Missouri-Columbia


    OCR - see oxidizable carbon ratio


    18O/16O ratios - see oxygen isotope record


    Oppel zone - see biozone


    optical dating - see optically stimulated luminescence


    optically stimulated luminescence (OSL)

       period - 100 - 500000 bp

       mode - radiogenic electron accumulation in crystalline defects is released when

          exposed to light or lasers, amount of luminescence reflects time since last exposed

          to sunlight or high heat

       materials - quartz, alkali feldspars, sediments, colluvia, stone surface, rhyolites, sand,

          zircon, feldspars, coversands, aeolian sediments, dune sands, sedimentary quartz,

          shoreline deposits, silty or sandy water deposited sediments, unheated sediments,

          mineral crystals, fired ceramics, soils, pottery, clays, art objects, micas, mixed silicates,

          sherds, quartz and feldspar rich sediments, burnt flints, sediments from archaeological

          sites, calcite, fimic anthrosol, Al2O3:C, potassium feldspars, tephra glass, bricks,

          granite, tsunami-laid sands, glaciofluvial sediments, buried podsols, organic-rich sediments,

          flood deposits, porcelain, flint, diatoms, loess, annealed quartz, fluvial sediments,

          lacustrine deposits, sand wedges, alluvial gravels

       measures - human occupation, colonisation, authenticity, dune migration, lateral migration rate

          of a meander, sand deposition, agricultural activity, fluvial deposits, retrospective dosimetry,

          soil erosion, cultural activities, time of construction and destruction of a building, paleoclimate

          changes, loess deposition, bedload transport processes, lake level chronologies

       synonyms - optical dating, OSL, pulsed photostimulated luminescence, cathodoluminescence,

          luminescence dating, blue-light stimulated luminescence (BLSL), infrared stimulated

          luminescence (IRSL)


    orbital dating - see cyclostratigraphy


    orbital forcing - see cyclostratigraphy


    orbitally tuned cyclostratigraphy - see cyclostratigraphy


    orbitally tuned geological timescale - see Astronomical time scale


    orbitally tuned stratigraphy - see cyclostratigraphy


    orbitally tuned time scale - see Astronomical time scale


    orbital stratigraphy - see cyclostratigraphy


    orbital time scale - see Astronomical time scale


    orbital tuning - see cyclostratigraphy


    OSL - see optically stimulated luminescence


    ostracode assemblages

       materials - ostracodes

       measures - hydrograph, lake level, paleoclimate


    ostrich eggshell dating - see amino acid racemization


    otolith growth lines

       period - 0 - 5000 bp

       mode - yearly growth bands in fish ear bones

       materials - otoliths

       measures - age, climate history, paleoenvironment, growth rates, oxygen isotopes


    oxidizable carbon ratio

       period - 1 - 35000 bp

       mode - site-specific rate of biodegradation of carbonized organic matter, ratio of total

          carbon to readily oxidizable carbon reflects amount of time passed

       materials - soil, carbonized organic matter, soil humic material or charcoal,

          active pedogenic and nonpedogenic sediments, stratified riverbanks, glacial deposits,

          formerly pedogenic buried soils (paleosols), open-air surfaces, vessicular soils,

          stratified fluvial deposits, desert pavements

       measures - cultural features, abandonment, pit features, geoglyphs, middens,

          earthworks, mounds, sub-plowzone sites

       synonyms - OCR


    oxygen isotope chronostratigraphy - see oxygen isotope record


    oxygen isotope ratios - see oxygen isotope record


    oxygen isotope record

       period - 0 - 500 m. bp

       mode - stable isotope variation

       materials - water, foraminifera, travertine, sediments, ice cores, meteorites, shelly material,

          deep sea sediments, skeletal material, tephras, arc magmas, biogenic silica,

          volcanic rocks, adularia, speleothems, calcite, gyttja, arkose, plankton, nannofossils,

          lacustrine calcareous deposits, oxide grains, carbonates, teeth, cellulose,

          wood, tree rings, otoliths, zircon

       measures - hydrothermal alteration, ore deposition, warming effect of volcanic C02,

          paleoceanography, marine terraces and coastal landforms, sea level, salinity,

          ice sheets, temperatures, ice volume, 41-k.y. cycles, obliquity forcing, precession,

          global temperatures, ice ages, climatic variation, cooling effect of aerosols,

          palaeoenvironmental records, meltwater spikes, stadials and cold rebounds,

          Dansgaard-Oeschger cycles, petrogenesis, climatic response to traps emissions,

          cold episodes, volume of the ocean, thermal history of shales, formation depth,

          oceanic productivity, early solar system, solar evolution, sea-surface paleotemperatures,

          monsoon intensities, rainfall amounts, river levels, diet, migrations, tectonic activity

       synonyms - 18O/16O ratios, oxygen isotope chronostratigraphy, oxygen isotope ratios,

          oxygen isotope stratigraphy, 18O stratigraphy

       labs - 1) Stable Isotope Laboratory - University of Arkansas

            2) Stable isotope facility, University of Kansas


    oxygen isotope stage - see marine isotope stage


    oxygen isotope stratigraphy - see oxygen isotope record


    231Pa/230Th ratio

       materials - basalts, marine phosphorites, ocean sediments, corals

       measures - thermohaline circulation


    231Pa/235U ratio

       materials - desert varnish

       measures - age



       period - 0 - 4 b. bp

       mode - process derived change in altitude

       materials - trees, rocks, sediments, biogenic materials

       measures - paleoenvironment, sea levels, paleoclimate, geomorpholgy



       period - 30000 - 4 m. bp

       mode - early human studies

       materials - fossil bones, tooth enamel, tools

       measures - human evolution, modern human origins



       labs - Paleobiogeochemistry Lab at the University of Kansas



       period - 0 - 600 m. bp

       mode - life studies in situ

       materials - fossils, sediments, faunas, flora, foraminifera

       measures - ecologies, evolution, palaeoenvironments, paleoclimate, biozones,

           paleoclimate change, life paleodistribution

       synonyms - biogeography, paleoecology, paleogeography

       labs - University of Kansas Biodiversity Institute



       period - 0 - 500 m. bp

       mode - life studies in vivo

       materials - fauna, flora, fossils, bioresidues

       measures - evolution, environmental adaptation



       period - 0 - 425 m. bp

       mode - botanical variation

       materials - fossil flora, sediments

       measures - surface temperatures, ecologies, evolution, palaeoenvironments,

           paleoclimate, paleodiversity, extinction events

       synonyms - archaeobotany, paleoethnobotany

       labs – 1) University of Kansas Biodiversity Institute

              2) Paleoethnobotany Laboratory, University of Missouri-Columbia



       period - 0 - 4 b. bp

       mode - oceanic change

       materials - foraminifera, calcareous nannoplankton, sediments, diatoms

       measures - basin structural, fluid, and ecological change, insolation, interglacials,

          carbonate dissolution and accumulation, deep-water circulation, salinity,

          sediment supplies, alkenone levels, ocean acidification, paleoclimate

       labs - 1) Paleontology Laboratory - Indiana State University



       period - 0 - 4 b. bp

       mode - climatic imprints

       materials - speleothems, ice cores, diatoms, pollen, peat, nannofossils, sediments,

          foraminifera, shell, carbonates, stalagmites, gastropods, ostracods, rock varnish,

          tree rings, loess, rock hyrax urine deposits, arctic algae

       measures - climate change, ecological and geological effects, monsoons, precipitation,

          meltwater pulses, glacial-interglacial cycles, Heinrich events, Bond events,

          volcanic eruptions, temperature change, insolation, cycles of obliquity, eccentricity

          and precession, sedimentation rates, climate reconstructions, cultural impacts,

          floods, sea and lake levels, droughts, Dansgaard/Oeschger cycles, forcing factors,

          atmospheric and ocean circulation, carbon dioxide levels, solar variability

          forest limits, sea-ice cover

       labs - 1) Tree-Ring Laboratory - University of Arkansas

          2) Indiana State University Biogeography and Dendrochronology Laboratory


    paleodiet reconstruction

       mode - isotopic variation, dental microwear, paleobiogeographics

       materials - bones, teeth, stomach contents, vessel food residue, feces, pollen

       measure - paleoeconomy, subsistence practices, radiocarbon reservoir offsets,

          migrations, diet controlled disease, residential mobility



       period - 0 – 675 m. bp

       mode - local ecological reconstructions

       materials - fungi, algae, pollen, fossils, non-pollen palynomorphs, lake sediments,

          calcareous nannofossils, foraminifera, trilobites, faunas, sediments, phytoliths,

          flora, trees, bone, teeth

       measures - fires, paleoclimate, biotas, palaeoenvironments, climate response,

          water depth, flora and fauna, paleodiet

       synonyms - palaeoenvironmental reconstruction, paleoethnobotany

       labs - 1) Paleoethnobotany Laboratory, University of Missouri-Columbia


    paleoenvironmental reconstruction

       period - 0 - 4 b. bp

       mode - zonal environmental reconstructions

       materials - faunas, sediments, lake sediments, flora, pollen, peat, insect assemblage,

          sagebrush growth rings, tree rings, macrofossils, teeth, biogeochemicals,

          packrat middens, loess, palaeosols, sapropels, algae

       measures - humidity, aridity, rock genesis, paleoclimate, topography, ice sheets,

          vegetation, paleotemperatures, erosion, fire histories, human environmental impact,

          human settlements, migrations, paleodiet

       labs - Paleoenvironmental Laboratory, University of Kansas


    paleoethnobotany - see paleoecology, paleobotany

       labs – 1) University of Kansas Biodiversity Institute

              2) Paleoethnobotany Laboratory, University of Missouri-Columbia


    paleogeographic reconstruction - see paleogeography



       period - 0 - 4 b. bp

       mode - geographic change

       materials - sediments, fossils

       measures - human occupation history, environmental change, water basin dynamics,

          climatic change, population migration, uplift, tectonics, denudation, sea levels,

          continental drift, drainage change, coal distribution, sediment accumulation,

          paleoclimate, paleotopography

       synonyms - paleobiogeography, paleogeographic reconstruction, geomorphology



       period - 300 - 3 m. bp

       mode - lake sediment analysis

       materials - lake sediments, diatoms, pollen, algae

       measures - environmental change, catchment disturbance, lake levels

       synonyms – lake sediment successions

       labs - 1) Paleolimnology Laboratory - University of Arkansas


    paleomagnetic dating

       period -

           polar wander path - 0 - 100000 bp

           geomagnetic pole reversals - 780000 - 500 m. bp

           apparent polar wander paths - back to Precambrian times

       mode - based on comparison between the current magnetic field and rock remanent

          geomagnetic directions and intensity

       materials - lavas, clays, settled volcanic ash, loess, iron sulphides, greigite, pyrrhotite,

          sediments, strongly heated samples found near igneous events, magnetite

       measure - fireplaces, kilns, structural fires, magnetic anomalies, planetary core,

          uplift, plate tectonics, denudation, continental drift, seafloor spread, Mars,

          orogenesis, paleoclimate, solar activity, cosmic ray intensity

       synonyms - archaeomagnetic dating, magnetostratigraphy, paleomagnetic stratigraphy

       labs – 1) Berkeley Geochronology Center


    paleomagnetic stratigraphy - see paleomagnetic dating, magnetostratigraphy


    Paleontological Time Scale

       period - 0 - 650 m. bp



       period - 0 - 650 m. bp

       mode - study of life change

       materials - fossils, sediments

       measure - evolution, sediment age

       synonyms - micropalaeontology, invertebrate paleontology, vertebrate paleontology

       labs - 1) Paleontology Laboratory - Indiana State University

            2) Paleontological Instutute, University of Kansas

            3) Paleontology Laboratories, Sam Noble Oklahoma Museum of Natural History


    paleopalynology - see palynology


    paleoprecipitation records

       period - 0 - 500000

       mode – climate proxy data

       materials - tree-rings, loess

       measure - monsoon precipitation, drought, rainfall variability, erosion


    paleoshoreline analysis - see lake level analysis


    paleosol analysis

       period - 0 - 10000 bp

       materials - sediments, paleosols

       measures - desertification, soil changes

       synonyms - soil geomorphology


    paleotemperature reconstruction – see paleothermometry



       period - 0 - 4 b. bp

       mode - reconstructing regional and local climatic responses to changing

           atmospheric conditions

       materials - fossil assemblages, loess sediments, gastropod shells, foraminifera,

           ocean sediments, ostracodes, alkenones

       measures - paleotemperatures, glacial-interglacial cycles, alkenones, thermal

           history reconstruction, sea-surface temperatures

       synonyms - amino acid paleothermometry, alkenone paleothermometry


    paleotopography - see geomorphology

       period - 0 - 4 b. bp

       materials - sediments, fossil assemblages

       measures - major and minor tectonism, glacial effects, erosion, mineral placement,

           exhumation, orogenesis, geomorphic change, landscape evolution



       period - 0 - 220 m. bp

       mode - changes in types of pollen grains

       materials - sediments, peat, gyttja, pollen, non-marine facies

       measures - lake basins, past environments, people's lifestyles, floral range and diversity,

          sea levels, condition of the forest, prevailing wind direction, pollen traveling distance,

          floral pathogens, lake sedimentation rate, reconstructing climates, dating soil strata,

          human occupation history, carbon accumulation rates, mire ecosystems,

          deforestation, landscape change, peat-bogs ecosystems, paleotemperature,

          mean temperature of the coldest month, paleoprecipitation, lake-level change

       synonyms - pollen profiles, paleobotany, paleopalynology


    palynomorph zone dating

       period - 0 - 400 m. bp

       mode - genera-specific horizon markers

       materials - fungal spores, algae spores, invertebrate remains, protozoa,

          dinoflagellates, acritarchs, tasmanites

       measures – deposit age


    palynostratigraphy - see palynology


    paper dating

       period - 0 - 100 bp

       mode - characteristic analysis

       materials - paper

       measures - authenticity, age



       mode - determine the age of artifacts, relative to others, by comparing the thickness

          of the patina

       materials - bronze, glass, stone artifacts, rock art, flint artifact, petroglyphs

       measures – age


    Pb age - see U/Pb dating, 207Pb/206Pb


    210Pb dating

       period - 0 - 150 bp

       mode - 222Rn decays to 210Pb in the atmosphere which settles immediately

       materials - lake and loess sediments, peat deposits, marine sediment, glacial ice,

          floodplain deposits, soils

       measures - local, regional and global climate conditions, sedimentation rates,

          soil erosion, environmental change, landscape changes

       synonyms  -  210Pb geochronology


    210Pb geochronology - see geochronology, 210Pb dating


    Pb/He dating - see helium-lead dating


    Pb isotopic age  - see Pb-Pb dating, U/Pb dating


    Pb-Pb dating

       period - 100 m. - 4.57 b. bp

       mode - isochron dependant on initial ratios of 206Pb/204Pb and 207Pb/204Pb

       materials - meteorites, CAIs, chondrules, whole rock, pyrrhotite, tourmaline, zircon,

          angrites, galena, chondrites, basaltic achondrite, phosphates, feldspar, sulfides,

          eucrites, troilite, Fe-meteorites, pyroxene, enstatite

       measures - Earth, Mars, Moon, early solar system, metamorphism, mineralization,

          Geochron, nebula events, heating events, asteriod parent bodies, Shallowater closure

       synonyms - Pb isotopic age, U/Pb dating, Pb-Pb isochron age


    207Pb/206Pb - see U/Pb dating


    Pb-Pb isochron age - see Pb-Pb dating


    Pb-Pb system - see Pb-Pb dating


    107Pd-107Ag dating

       period - 4565 m. - 4571 m. bp

       mode - extinct radionuclide 107Pd produced excess 107Ag

       materials - meteorites, iron meteorites, pallasites, sulfides, chondrites

       measures - early solar system, planetary evolution



       mode - archaeological soils analysis

       materials - soils, plant remains, terraced soils

       measures - erosion rates, subsistance, agricultural methods

       synonyms - archaeological pedology



       period - 0 - 500 m. bp

       mode - a body of rock that consists of one or more pedologic horizons developed in

          one or more lithic units now buried by a formally defined lithostratigraphic, or

          allostratigraphic unit or units (NASC)

       materials - buried soils, geosols

       measures - relative age


    Phanerozoic Time Scale

       period - 0 - 675 m. bp


    phylogenetic comparison - see DNA analysis


    pigment dating

       mode - known pigment availability

       materials - hematite, charcoal, paint

       measures - rock paintings, paintings, pictographs, authenticity


    planktonic stratigraphy

       materials - alkenones, foraminifera, phytoplankton

       measures - stable isotopes, ocean circulation, Heinrich events


    plutonic geochronology - see geochronology


    pollen profiles - see palynology


    potassium-argon dating

       period - 20000 - 4.6 b. bp

       mode - potassium-40 decays to argon-40 which is trapped in mineral, accumulation

          reflects time since highly heated

       materials - andesite, basalt, biotite, muscovite, hornblende, volcanic feldspar, micas,

          plagioclase, clays, volcanic glass, igneous rocks, bentonites, lavas, sanidine,

          meteorites, heat treated projectile point, pottery, volcanic ash, sediments, alunite

       measure - sea floor spreading rates, early humans, thermal histories,

          paleontological zones, age of earth, mineral formation, cave formation

       synonyms  -  K-Ar dating, K–Ar geochronology


    244Pu fission track thermometry

       materials - meteorites, chondrites, hibonite, CAIs,

       measures – cooling rates


    pulsed photostimulated luminescence - see optically stimulated luminescence


    Pu-Xe dating

       period - 4565 - 4571 m. bp

       mode - extinct radionuclide

       materials - zircon, eucrites, meteorites

       measures – early solar system


    quartz hydration dating

       period - 1600 - 25000 bp

       mode - water diffusion into quartz forms a hydration layer, thickness of layer

          indicates time elapses since fresh surface

       materials - quartz artifacts

       measures - art authentication

       synonyms  - hydration dating


    226Ra excess dating - see 238U-230Th-226Ra dating


    226Ra/230Th dating - see 238U-230Th-226Ra dating


    radiation exposure dating - see electron spin resonance, optically stimulated

       luminescence, thermoluminescence


    radioactive dating - see radioisotope dating


    radiocalcium dating - see 41Ca dating


    radiocarbon dating

       period - 0 - 50000 bp

       mode - incorporation of modern 14C stops when the lifeform dies, the water goes

          underground, the iron is smelted, or air vesicles in lava close, then through beta

          particle emission reverts to stable 14-nitrogen, carbon-14 content decrease relates

          to age, also cosmogenic in some minerals

       materials - ice cores, water, soils and sediments, micro- and macro-fossils, charcoal,

          wood, humic acids, speleothems, caliche, lime, marl, travertine and tufa, peat,

          pollen, tree rings, plant and animal tissues, iron, carbonate deposits, groundwater,

          quartz, varves, desert varnish, diatoms, silk, petroglyphs, stalagmites, shell, fabrics,

          teeth, bone, ivory, cotton, corals, organic materials, gyttja, detritus mud, loess,

          lake sediments, food residue, alkenones, pottery, mortars, papyri

       measure - event chronologies, rock art, climate change, ecosystem change, diet,

          time of harvest, authenticity, solar activity, Neanderthals, Neolithic events,

          nuclear energy pollution, oceanic circulation, site occupancy, deposition time,

          microfossil deposition rate, sedimentation rates, stable isotope variation,

          modern birth date

       synonyms  - carbon 14 dating, 14C dating, bomb-radiocarbon dating

       labs - 1)  Arizona Geochronology Center, University of Arizona

          2) Beta Analytic, Inc., Miami, Florida

          3) Quaternary Isotope Laboratory, University of Washington

          4) INSTAAR Laboratory, University of Colorado


    radiocarbon geochronology - see geochronology


    radiochlorine - see 36Cl dating


    radiochronology - see radioisotope dating


    radiogenic dating - see radioisotope dating


    radiogenic Helium - see 4He/3He Thermochronometry


    radiogenic nitrogen

       mode - 14C decay product analysis


    radioisotope dating

       period - 0 - 6 b. bp

       mode - chronometric dating based on known half-lives of particular isotopes or the

          rate of other cumulative changes resulting from radioactivity

       materials - igneous, sedimentary, and metamorphic rocks, bio-remains, meteorites,

          lunar rocks, ores, groundwater, environmental contaminants

       measures - evolution, orogeny, early solar system development, paleoclimate,

          paleoecology, geologic processes, source tracing

       synonyms  - radioactive dating, radiochronology, radiogenic dating, radiometric dating,

         radioisotopic geochronology


    radioisotopic geochronology  - see radioisotope dating


    radioisotopic time scale

       period - 0 - 5700 m. bp

       mode - built on radioisotopic dates

       synonyms  - radiometric time scale


    radiolarian zone dating

       period - 0 - 65 m. bp

       mode – type specific chronostratigraphic index markers

       materials - intervolcanic sediments, silica enriched sediments, radiolarians

       measures - age



       period - 0 - 150000 bp

       materials - zircon, feldspar, sediments

       measures - age

       synonyms - luminescence


    radiometric dating - see radioisotope dating


    radiometric time scale - see radioisotopic time scale


    Rb-Sr dating

       period - 60 m. - 4.6 b. bp

       mode - radioisotope parent 87Rb produces daughter 87Sr

       materials - mica, rocks, igneous rock, biotite, muscovite, hornblende, granite, CAIs,

          amphiboles, limestones with abundant strontium, pegmatites, plagioclase, feldspar,

          K-feldspar, orthoclase, gneiss, sulfides, sphalerite, illitic clays, alkaline halides,

          shales, potassium and cesium minerals, lepidolite, amazonite, microcline, syenite,

          magnetite, chondrites, nepheline, meteorites, lunar rocks, dunite

       measures - cooling ages, uplift and cooling history, metal deposits, heating events,

          sediment sourcing, metamorphism

       synonyms  - rubidium/strontium dating

       labs - Department of Geology, University of Kansas


    red shift dating

       mode - spectral shift with distance

       materials - stars, galaxies, supernovae

       measures - early universe, universe expansion rate change


    rehydroxylation dating

       period - 0 - 10000 bp

       mode - precision mass analysis of moisture absorption over time

       materials - ceramics, bricks, tile, pottery

       measures - climate, ceramic forgery


    relative dating

       period - 0 - 13.7 b. bp

       mode - provides a sequence of past events without the numerical age provided by

          absolute dating but may be related to and mapped onto an absolute timescale


    Re-Os dating

       period - 10 m. - 4.6 b. bp

       mode - radioisotope parent-daughter 187Re produces 187Os

       materials - igneous rocks, iron meteorites, molybdenite, pyrite, sulfide ores, pyrrhotite,

          pallasites, sedimentary rock

       measures - Au deposition, Pb-Zn deposits, Cu-Ni deposits, glacial history

       synonyms  - rhenium-osmium dating


    rhenium-osmium dating - see Re-Os dating


    rock varnish dating - see varnish stratigraphy


    rubidium/strontium dating - see Rb-Sr dating


    samarium-neodymium dating - see Sm-Nd dating


    sapropel chonology

       mode - laminated organic-rich layers

       materials - marine sediment, tephra, alkenones

       measures - paleoclimate, paleoenvironment reconstruction

       synonyms  - sapropel markers


    scale growth lines

       mode - growth lines in fish scales

       materials - fish scales

       measures - age in fish, gadids, flounders, bluefish, sea bass, weakfish, scup,

          striped bass


    scientific dating

       mode - relative and absolute dating methods


    seafloor anomaly timescale - see geomagnetic polarity time scale


    seafloor spreading rates

       period - 0 - 180 m. bp

       materials - rift volcanics, ocean sediments

       measures - plate tectonics, continental drift


    sea level variation

       period - 0 - 200 m. bp

       mode - level markers

       materials - coral reefs, sediments

       measures - paleoclimate, meltwater pulse, transgressions, tectonics, uplift,

          paleogeography, regressions, glacial melting, population displacement


    secular variation magnetostratigraphy - see magnetostratigraphy


    sedimentation rate chronology

       period - 0 - 146 m. bp

       mode - rate of sediment buildup allowing for compaction

       materials - lake sediments, sea bed deposits, tephra, marsh deposits

       measures - past environments, paleoclimate, fire frequencies, caves, erosion,

          paleoecology, biostratigraphic events, paleoceanography, lake levels,




       period - 0 - 4 b. bp

       mode - study of sedimentary deposits and sedimentation

       labs - Department of Geology, University of Kansas



       mode - subsurface unit differentiation with seismic waves


    sequence dating

       mode - place assemblages of artifacts into relative order

       materials - pottery, artifacts

       measures - relative age


    sequence stratigraphy

       mode - marker beds

       materials - seismites, tephras, tempestite, turbidites, hardgrounds

       measures - palaeoecology, faunal migrations, event deposits, faunal signatures,




       mode - artifact lenticular change, artifact's popularity rises to a high point and then

          trails off

       materials - pottery, artifacts

       measures - ceramics, points, material cultural remains


    shell growth lines

       mode - growth lines in shellfish

       materials - mollusc valves, chondrophores, shell

       measures - age in molluscs, surfclams, quahogs, scallop, clam


    SHRIMP U-Pb age – see U/Pb dating


    32Si dating

       period - 30-1000 bp

       mode - cosmogenic surface exposure isotope production

       materials - diatoms, marine sediments

       measures – paleoclimate, paleoenvironment, sedimentation rates


    146Sm-142Nd dating

       period - 4.5 – 4.6 b. bp

       mode - extinct natural radionuclide produced 142Nd

       materials - meteorites

       measures - early solar system


    Sm-Nd dating

       period - 100 m. - 4.6 b. bp

       mode - radioactive decay of 147Sm to 143Nd

       materials - volcanic deposits, komatiites, scheelite, tourmaline, igneous and metamorphic

          rocks, garnet, meteorites, chondrites, mesosiderites , biostratigraphically barren strata

       measures - time of eruption, gold deposits, ore deposits, mantle, crust, early solar system,

          source tracing

       synonyms  - samarium-neodymium dating

       labs - Department of Geology, University of Kansas


    soil geomorphology - see paleosol analysis, geomorphology


    solar cyclicity

       measures - solar variations, paleoclimate, atmospheric 14C


    solar forcing - see cyclostratigraphy


    sonic astrochronology - see astrochronology


    spectroscopic dating

       mode - age related surface chemical change

       materials - wood

       measures - authenticity


    speleothem deposition

       mode - rough growth rate

       materials - speleothem

       measures - cave age


    spore dating

       period - 0 - 400 m. bp

       mode - fungi spore variation

       materials - peat, terrestrial sediments


    87Sr/86Sr geochronology

       period - 0 - 200 m. bp

       mode - seawater variations over time

       materials - shell, carbonate sediments

       measures - age

       synonyms  - 87Sr/86Sr stratigraphy, strontium isotope stratigraphy


    87Sr/86Sr ratios

       mode - 87Sr/86Sr isotopic ratios of local rock is same as that grown on or made of it

       materials - organics, products

       measures - sourcing, migration patterns, trade, forensics


    87Sr/86Sr stratigraphy - see 87Sr/86Sr geochronology


    stable isotope analysis

       period - 0 - 500 m. bp

       mode - consistent variation of non-radioactive isotopes

       materials - carbonates, shell, tephra, marine sediments, groundwater, foraminifera,

          ice cores, geologic materials, organic compounds, sapropels, alunite, marl, bone,

          lake sediments, stomach contents, food residue, wood , coral, otoliths, sclerosponge

       measures - fresh water flow, water salinity, hydrograph, vegetation change, climate change,

          uplift, hotspot, terrace deposits, precession, obliquity, eccentricity, mass extinctions,

          hydrothermal alteration, ore deposition, paleoclimate, orogenesis, period transitions,

          paleoceanography, agricultural activities, pollutant release, ocean temperatures

          subsistence, social class, reservoir effect, paleoenvironments, paleotemperatures,

          paleodiet, colonization, population movement

       synonyms - chemical isotope dating, isotopic dating

       labs - 1) Stable Isotope Laboratory - University of Arkansas

            2) Stable Isotope Laboratory - University of Missouri-Columbia

            3) University of Kansas Stable Isotope Laboratory


    standard global chronostratigraphic scale - see geologic time scale


    stratigraphic time-scale - see geological time scale



       period - 0 - 4.5 b. bp

       mode - based on the principle of superposition - if there are layers of deposits, those

          laid down first will be older than those laid on top of them

       materials - artifacts, fossils, rock, sediments, tephra

       measure - geological strata, evolution, geomorphism, paleoclimate, formations,

          paleoecology, early human, archaeology, biodiversity, paleogeography, taxon range

       see - age equivalent stratigraphic markers, allostratigraphy, aminostratigraphy,

          benthic isotope stratigraphies, biostratigraphy, chemostratigraphy, chronostratigraphy,

          climatostratigraphy, cyclostratigraphy, ecostratigraphy, event stratigraphy,

          global climatostratigraphic scale, isotope stratigraphy, isotopic event stratigraphy,

          lithostratigraphy, macrofossil stratigraphy, magnetic reversal stratigraphy,

          magnetic stratigraphy, magnetobiostratigraphy, magneto(cyclo)stratigraphy,

          magnetostratigraphy, microfossil stratigraphy, morphostratigraphy,

          nannofossil biostratigraphy, natural catastrophe stratigraphy, 18O stratigraphy,

          orbitally tuned cyclostratigraphy, orbitally tuned stratigraphy, orbital stratigraphy,

          oxygen isotope chronostratigraphy, oxygen isotope stratigraphy, paleomagnetic stratigraphy,

          palynostratigraphy, pedostratigraphy, planktonic stratigraphy, secular variation

          magnetostratigraphy, seismostratigraphy, sequence stratigraphy, 87Sr/86Sr stratigraphy,

          standard global chronostratigraphic scale, stratigraphic time-scale,

          strontium isotope stratigraphy, tectonostratigraphy, varnish stratigraphy

       labs - Department of Geology, University of Kansas


    strontium isotope stratigraphy - see 87Sr/86Sr geochronology



       materials – artifacts, petroglyphs, carvings, pottery, projectile points

       measures - art, architecture, writing authentication, culture


    subjects depicted

       mode - objects of art limited to certain time periods

       measures - rock art, carvings


    sulfur isotope analysis

       measures - environmental change, orogenesis, formation temperature



       mode - later image cut into or painted over earlier image

       measures - rock art


    surface-exposure dating - see cosmogenic dating


    T-cell DNA age

       mode - number of molecular agents decline with age

       materials - blood

       measure - human age


    tectonic geomorphology - see geomorphology



       measures - island arcs, peninsulas, highlands



       period - 0 - 5 m. bp

       mode - tephra layers' physical, chemical, spatial, and temporal characteristics

       materials - tephra, interspersed sediments, cryptotephras, ice cores

       measure - paleoclimate reconstruction, paleoenvironmental reconstruction, landscape

          reconstruction, vulcanology, geological and archaeological events, early man


    Te-Xe dating

       mode - radioisotope parent-daughter 130Te produces 130Xe

       measures - mineralisation


    230Th coral dating - see uranium/thorium dating


    230Th dating - see uranium/thorium dating


    thermochronology - see thermochronometry

       labs - Department of Geology, University of Kansas

       see also - 40Ar/39Ar thermochronology, detrital thermochronology, fission track thermochronology,

        high-temperature thermochronology, noble-gas thermochronology, Time-temperature models,

        (U-Th)/He thermochronology



       period - 0 - 6 b. bp

       mode - temperature-dependent systems that record the time that they passed through

          their specific closure temperature

       materials - apatite, monazite, K-feldspar, zircon, meteorites, titanite, pegmatites, mylonitic rocks,

          alkali feldspars, hornblende, biotite, granite, muscovite, quartz

       measures - metamorphism, arc-continent collision  zone, maturation of hydrocarbons,

          denudational history, cooling history, mountain-building, exhumation, subduction,

          faults, tectonic hazards, landscape development, tectonic geomorphology,

          hydrocarbon exploration, sedimentary burial history, timing and rates of

          development of topographic relief, architecture and dynamics of orogenic

          wedges, feedbacks between erosion, uplift, and climate, weathering episodes,

          wildfires, time-temperature histories, crustal thermal processes, mineralization,

          sedimentary basins, erosion, paleotopographic histories, detrital provenance,

          landscape evolution of mountain belts, tectonics, continental margins, glacial effects,

          cooling and uplift of blocks, episodic rapid uplift, geodynamics of orogenic belts,

          thermotectonic evolution of cratons, plate tectonics, convergent settings, economic

          hydrothermal ore deposits, depositional ages

       synonyms - low-temperature thermochronometry, noble-gas thermochronology,

          fission track thermochronology, zircon (U-Th)/He dating, 4He/3He

          thermochronometry, time-temperature models, detrital thermochronometry, U-Pb,

          noble-gas thermochronometry, argon-40/argon-39, detrital chronometry

          Ar thermochronometry, helium-helium thermochronometry, helium thermochronometry,

          (U-Th)/He thermochronometry



       period - 30 - 1 m. bp

       mode - radiogenic electron accumulation in crystalline defects is released when

          exposed to high temperatures, amount of luminescence reflects time since last

          exposed to high heat

       materials - rocks, minerals, pottery, quartz, feldspar, diamond, calcite, sands, silt,

          fire-cracked and fire treated rocks, sediment, fired clay, terracotta, bricks,

          tiles, obsidian, slag, granite, rhyolite, stoneware, porcelain, calcrete, shell,

          stalagmite, zircon, Iceland spar, apatite, meteorites, tephra, loess

       measure - authenticity, hearths, paleoclimate, impact craters, sediment provenance

       synonyms - TL, luminescence

       labs - Thermoluminescence Laboratory, University of Arkansas


    thermo-microbiological time of death

       mode - thermographic imaging of microorganism growth rate on cadavers

       measures - time of death


    Th/Eu nucleocosmochronology - see nucleocosmochronology


    thorium-230 dating - see uranium/thorium dating


    thorium-uranium disequilibrium - see uranium/thorium dating


    229Th-233U - see (U-Th)/He  dating


    230Th/234U dating - see uranium/thorium dating


    230Th/238U dating - see uranium/thorium dating


    230Th-234U-238U dating - see uranium/thorium dating


    time scale

      Astronomical Polarity Time Scale

      Astronomical time scale (ATS)

      cosmological time scale

      Early Solar System timescale

      Extinct Radionuclide Timescale

      geologic time scale

      Geomagnetic Polarity time scale

      geomagnetic reversal time scale

      Geomagnetic time scale

      isotopic time scale

      lunar geologic timescale

      magnetic anomaly time scale

      Martian geologic timescale

      orbital time scale

      Orbitally Tuned Geological timescale

      Paleontological Time Scale

      Phanerozoic Time Scale

      Prehistoric Time Scale

      radiometric time scale

      radioisotopic time scale

      Standard Global Chronostratigraphic Scale


    Time-temperature models - see thermochronometry


    TL - see thermoluminescence


    tree ring dating - see dendrochronology


    trilobite zone dating

       period - 440 - 570 m. bp

       mode – type specific chronostratigraphic index markers

       materials - trilobite, sediments

       measures - palaeoecology


    tritium analysis

       period - 0 - 100 bp

       mode - atmospheric cosmogenic

       materials - tree rings, groundwater, river water, marine water

       measures - hydrologics, groundwater flow and recharge rates, aquifers,

          surface water, bomb-tritium front, nuclear power plant impact,

          ocean current throughflow

       synonyms  - 3H dating


    tritium/helium-3 dating

       mode – compares ratio of tritium to helium-3

       materials - ground water

       measures - age


    tusk ring analysis

       mode - yearly growth layers

       materials - elephant tusks

       measures - famine records, birth events, age, health history


    type-series - see typology


    typological studies - see typology



       mode - cultural or evolutionary changes that allow artifacts to be placed

           into time sequences

       materials - artifacts, pottery, projectile points, axes, tools, language

       measures - relative age, archaeological periods, migration

       synonyms - type-series, typological studies


    U disequilibrium series dating - see uranium/thorium dating


    234U excess dating

       period - 10000 - 2 m. bp

       mode – 238U compared to its daughter 234U

       materials - groundwater

       measures - aquifers

       synonyms - 234U/238U dating, uranium-uranium dating


    U-Fl-N dating

       period - 0 - 100 m. bp

       mode - percolating ground water adds fluorine and uranium and removes nitrogen

       materials - buried bone, teeth, antlers

       measure - recent intrusions, pits and midden features

       synonyms - fluorine, uranium and nitrogen tests, fluorine analysis


    U/He dating - see (U-Th)/He  dating


    U-Pb Chronology - see U/Pb dating


    U-Pb chronometry - see U/Pb dating


    U/Pb dating

       period - 1 m. - 4.57 b. bp

       mode - coupled chronometer, 238U to 206Pb and 235U to 207Pb, lead atoms created by

          uranium decay are trapped in the crystal and build up in concentration with time

       materials - rocks, monazite, fossil bones, igneous and metamorphic rocks, powdered

          whole rocks, mineral concentrates, single grains, zircon, baddeleyite, sphene, rutile,

          apatite, titanite, moon rocks, meteorites, zirconolite, intrusives, sedimentary rocks,

          volcanic ash, rhyolite, tuff, hornblende, pyrrhotite, tourmaline, granites, feldspar,

          monazite, angrites, chondrites, CAIs, galena, phosphates, eucrites, intrusions,

          chondrules, lunar basalts, phosphates, detrital sediments, flysch, bentonite,


       measures - orogenic development, batholiths, sedimentary source, dykes, mineralization,

          volcanic eruptions, continental movements, mass extinctions, metamorphism,

          early solar system, Shallowater, nebular and parent-body processes,

          age of the Earth

       synonyms - U-Pb chronometry, zircon dating, U-Th-Pb method, Th/Pb dating,

          235U-207Pb dating, 238U-206Pb dating, U-Pb chronology, U–Pb geochronology,

          zircon SHRIMP age, SHRIMP U-Pb

       labs - Department of Geology, University of Kansas


    235U-207Pb dating - see U/Pb dating


    238U-206Pb dating - see U/Pb dating


    U–Pb geochronology - see geochronology, U/Pb dating


    U/ Pb zircon geochronology - see geochronology


    uranium disequilibrium series - see uranium/thorium dating


    uranium-series - see uranium/thorium dating


    uranium series disequilibrium dating - see uranium/thorium dating


    uranium series geochronology - see geochronology


    uranium/thorium dating

       period - 20 - .5 m. bp

       mode – solubility mechanics produce absorption rate differential

       materials - marine sediments, bone, wood, coral, stone, speleothem, carbonates,

          pumice, desert varnish, pottery, clays, soils, peat deposits, weathered alluvium,

          fluvial sediments, ferruginous concretions and rinds, lignite, calcrete, stalagmites,

          caliches, molluscs, teeth, carbonate coatings, calcite cement, lacustrine sediments,

          evaporites, phosphorites, marine shells, egg shells, carbonate sediments, travertines,

          annually-laminated sediments, impure carbonates, calcite laminations and veins,

          invertebrate fossils, lake cores, tephra, sulfides

       measures - interstadials, fault motion, sea levels, coastal dunefield, early human activity

           in caves, coastal plain, rock art, climate reconstruction, marine 14C reservoir correction,

           ore formation

       synonyms - 230Th/234U dating, 238U-234U-230Th-232Th dating, 230Th/238U dating,

          thorium-uranium disequilibrium, uranium-series, uranium series disequilibrium dating,

          thorium-230 dating, 230Th-234U-238U dating, 238U/230Th dating, 230Th/232Th,

          U-Th dating, 238U-series dating, U234/Th230 dating, 230Th coral dating,

          230Th dating, coral dating, uranium disequilibrium series


    uranium-uranium dating - see 234U excess dating


    238U-series dating - see uranium/thorium dating


    U234/Th230 - see uranium/thorium dating


    U-Th dating – see uranium/thorium dating


    238U/230Th dating - see uranium/thorium dating


    U-Th-He Chronometry - see (U-Th)/He dating


    (U-Th)/He dating

       period - 1 m. – 500 m. bp

       mode - alpha particles (4He nuclei) emitted throughout 238U, 235U, and 232Th

          decay series, trapped within the lattice of the host material, and build up in

          concentration with time

       materials - zircon, chondrites, titanite, apatite, goethite, tuff, detrital sediments

       measures - uplift and exhumation, denudation, structural and topographic evolution,

          low-temperature thermal history of the upper crust

       synonyms - (U-Th)/He thermochronometry, (U-Th)/He thermochonology, low-

          temperature thermochronometry, U/He dating, He dating, 4He/3He thermochronometry,

       U-Th-He Chronometry

       labs - U-Th)/He lab, University of Kansas


    (U-Th)/(He-Pb) age - see (U-Th)/He dating, U/Pb dating


    (U-Th)/He thermochronology - see (U-Th)/He dating


    (U-Th)/He thermochronometry - see (U-Th)/He dating


    U-Th-Pb geochronology

       labs - Department of Geology, University of Kansas


    U-Th-Pb method - see U/Pb dating


    238U-230Th-226Ra dating

       materials - andesites, dacites, pumice, fluvial sands

       measures – age

       synonyms - 226Ra/230Th dating, 226Ra excess dating


    234U/238U dating - see 234U excess dating


    238U-234U-230Th-232Th dating - see uranium/thorium dating


    varnish microlaminations - see varnish stratigraphy


    varnish microstratigraphy - see varnish stratigraphy


    varnish stratigraphy

       period - 1000 - 2 m. bp

       mode - rock surface biochemical deposit growth rate

       materials - rock, rock cobbles, lava flows, meteorites

       measures - rock carvings, petroglyphs, stone artifacts, debris-flow fans,

          lava flows, faulting events, meteoric events, sediment deposition, environmental

          changes, climate record, geomorphism

       synonyms - rock varnish dating, cation-ratio dating, desert varnish,

          varnish microstratigraphy, VML dating, varnish microlaminations


    varve chronology

       period - 0 - 40000 bp

       mode - layered annual silt deposits

       materials - lake sediments, terrestrial macrofossils, marine sediments, clays, silt,

          fine sand, tephra

       measure - palaeoclimate, organic carbon, deglaciation, precipitation, flooding, drought,

          rates of change in climate and various ecosystems, forest pathogen, paleoecology,

          sedimentation rate

       synonyms - annually laminated sediments, varved clays, lake sediment successions,

          laminated sediments


    varved clays - see varve chronology


    vertebrate paleontology

       labs - University of Kansas Biodiversity Institute


    VML dating - see varnish stratigraphy



       mode - degree of weathering

       measures - rock art


    written records

       period - to about 5000 BP


    Xe-Xe Dating

       materials - telluride minerals, meteorites


    zircon dating - see U/Pb dating


    zircon FT system - see fission-track dating


    zircon SHRIMP age - see U/Pb dating



       mode – comparative identification

       materials – animal remains, faunal assemblage

       measures - diet, ecology, paleoclimate, evolution

       synonyms - archaeozoology

       labs - 1) Zooarchaeology Laboratory - University of Missouri-Columbia

             2) Zooarchaeology Laboratory of the Peabody Museum – Harvard

             3) Zooarchaeology Lab UCLA

             4) Zooarchaeology Lab – University of Oregon



The North American Commission on Stratigraphic Nomenclature

The American Association of Petroleum Geologists Bulletin

Volume 67, Number 5 (May, 1983), p. 841-875


Dating Methods/Pattern Recognition – Proposed Syllabus


Chronological Studies & Dating Methods - Time Periods


Chronological Studies & Dating Methods - Materials


Chronological Studies & Dating Methods - Databases




Contact for comments, suggestions, or references



Revised 6/26/15


Pub 9/11