Can absolute dating be used in scientific studies?  Yes!

     Modern science depends on the testing of hypotheses and the analysis of data.  Scientists publish their data in refereed scientific journals.  Absolute dating is used by professional scientists who have been trained in their field and publish their data in these respected scientific journals.  Below is a sample list of scientific papers which use relative dating techniques; this is only a tiny fraction of the actual number of papers that have been published.   There have been tens and tens of thousands of scientific papers published which use radiometric dating.

      Although there are those who criticize all absolute dating, in general they are not professional scientists, they are not trained in relevant fields of study, and they do not publish in respected scientific journals

 

 

 

K/Ar

--strata with hominid fossils are dated between 2.6 and 3.1 million years

Aronson, J. L.  New geochronologic and palaeomagnetic data for the hominid-bearing Hadar formation of Ethiopia.  Nature 267: 323-7.  !977.

--strata with hominoid primates are dated at 16-17 million years old

McDougall, Ian.  Age of hominoid-bearing sequence at Buluk, Northern Kenya.  Nature 318: 175-8.  1985.

--various strata are dated; some date hominid fossils

McDougall, Ian.  K-Ar and Ar/Ar dating of the hominid bearing Pliocene-Pleistocen sequence at Koobi For a, Lake Turkana, northern Kenya.  Geol. Soc. Am. Bull.  96: 159-75.  1985.

--strata with relevance to hominid fossils is dated at 1.7 million years old

Hurford, Anthony.  Fission track dating of a vitric tuff from East Rudolf, North Kenya.  Nature 249: 236-7.  1974.

--strata with relevance to hominid fossils is dated at 2.4 million years old

Fitch, F.  Ar/Ar dating of KBS Tuf in Koobi For a Formation, East Rudolf, Kenya.  Nature 263: 740-2.  1976.

--strata with relevance to hominid fossils is dated at 3.8 million years old

Leakey, M.  Fossil hominids from Laetoli beds.  Nature 262: 460-6.  1976.

--calibration of strata formed during recorded history

Renne, P.  Ar/Ar dating into the historical realm: Calibration against Pliny the Younger.  Science 277: 1279-30.  1997.

--dating strata with relevance to hominid fossils

Fitch, F.  Radioisotopic age determination of Lake Rudolf Artefact Site.  Nature 226: 226-8.  1970.

--strata which contained hominid fossils is dated at 1.6 million years

McDougall, Ian.  Age of the Okote Tuff Complex at Koobi For a, Kenya.  Nature 316: 792-7.  1985.

--strata from the Late Cretaceous are dated

Cifelli, Rich.  High-precision Ar/Ar geochronology and the advent of North America’s Late Cretaceous terrestrial fauna.  Proc. Natl. Acad. Sci. USA. 94: 11163-7.  1997.

--strata relevant to dating hominid fossils are dated

Curtis, G.  Age of KBS Tuff in Koobi For a Formation, East Rudolf, Kenya.  Nature 258: 395-8.  1975.

--lunar material is dated at 3.7 billion years old

Turner, Greenville.  Argon-40/Argon 39 dating of lunar rock samples.  Science 167: 466-8.  1970.

--lunar material is dated at 3.3 billion years old

?  Argon 40-Argon 39 Dating of Apollo Sample 15555.  Science 175: 417-9.  1972.

 

 

URANIUM SERIES DATING

--West Australian strata dated at 2.7 billion years old

Sylvester, Paul.  Niobium/Uranium evidence for early formation of the continental crust.  Science 275: 521-3.  1997.

--hominid fossils are dated at 228 thousand years old

Harmon, Russell.  Th/U dating of travertine from the Bilzingsleben archaeological site.  Nature 284: 132-5.  1980.

--Australian strata dated at 3.7 billion years old

Scharer, Urs.  Determination of the age of the Australian continent by single grain zircon analysis of Mt. Narryer metaquartzite.  Nature 315: 52-5.  1985.

--lunar material is dated at 4.7 billion years old

Gopalan, K.  Rubidium-strontium, uranium, and thorium-lead dating of lunar material.  Science 167: 471-3.  1970.

--lunar rocks dated at 4.1 billion years old and lunar dust at 4.6 billion years old

Silver, Leon.  Uranium-thorium-lead isotope relations in lunar materials.  Science 167: 468-71.  1970.

--Mid-Atlantic basalts are dated and the age of the earth is estimated

Ulrych, T.  Oceanic Basalt leads: a new interpretation and an independent age for the earth.  Science :252-6. 1967.

--lunar material dated at 4.7 billion years old

Kohman, Truman.  Lead and thallium isotopes in Mare Tranquillitatis surface material.  Science 167: 481-3.  1970.

--lunar material is dated at 4.6 billion years old

Tatsumoto, M.  Age of the moon: an isotopic study of uranium-thorium-lead systematics of lunar samples.  Science 167: 461-3.  1970.

--meteorites are dated at 4.5 billion years old

Tatsumoto, M.  Time differences in the formation of meteorites as determined from the ratio of laed-207 to lead 206.  Science 180: 1279-83.

--minerals in Western Australian are dated at 4.1-4.2  billion years old

Froude, D.  Ion microprobe identification of 4,100-4,200 Myr-old terrestrial zircons.  Nature 304: 616-8.  1983.

--minerals in Western Australian are dated at 4.2  billion years old

Compston, W.  Jack Hills, evidence of more very old detrital zircons in Western Australia.  Nature 321: 766-9.  1986.

 

 

RUBIDIUM/STRONTIUM

--an iron meteorite is dated at 4.7 billion years old

Wasserburg, G.  Strontium-rubidium age of an iron meteorite.  Science 150: 1814-7.  1965.

--a meteorite is dated at 4.6 billion years old

Allegre, C.  Rubidium-87/Strontium-87 age of Juvinas basaltic achondrite and early igneous activity in the solar system.  Science 187: 436-8.  1975.

--a Western Australia strata is dated at 3.3 billion years old by Rb/Sr and Sm/Nd dating

Early Archaean gneisses from Yilgarn Block, Western Australia.  Nature 292: 322-3.  1981.

-- a South African strata is dated at 3.3 billion years old by Rb/Sr and Sm/Nd dating

Barton, J.  Rb-Sr age and source of the bimodal suite of the ancient gneiss complex, Swaziland.  Nature 283: 756-8.  1980.

--chondrite is dated at 4.5 million years old

Minster, J.  Absolute age of formation of chondrites studied by the Rb-Sr mehtod.  Nature 300: 414-8.  1982.

--lunar sample is dated at 3.3 billion years old

Murthy, V.  Rubidium-strontium and potassium-argon age of lunar sample 15555.  Science 175: 419-21.  1972.

--lunar rocks are dated at 4.4 billion years old

?Rubidium-Strontium age and elemental and isotopic abundances of some trace elements in lunar samples.  Science 167: 476-9.  1970.

--igneous lunar rocks are dated at 3.8 billion years

Compston, W.  Rubidium-Strontium chronology and chemistry of lunar material.  Science 167: 474-5.  1970

--isotopic analysis of lunar material

Hurley, P.  Rubidium-Strontium relations in tranquility base samples.  Science 167: 473-4.  1970.

--lunar rocks dated at 3.6 billion years old

Albee, A.  Ages, Irradiation history, and chemical composition of lunar rocks from the Sea of Tranquility.  Science 167: 463-6.  1970.

CARBON 14

--analysis of 30,000 years of Brazilian sediments

Stute, M.  Cooling of tropical Brazil during the last glacial maximum.  Science 269: 379-82.  1995.

--dating activity in the Bering land bridge

Elias, Scott.  Life and times of the Bering land bridge.  Nature 382: 60-3.  1996.

--dating aquatic fossils at various sites

Burleigh, Richard.  Radiocarbon dating of freshwater shelles from Laeng Burung 2.  Mod. Quaternary Res. SE Asia 6: 51-6.  1981.

--calibration for entire 45,000 years of radiocarbon record

Kitagawa, H.  Atmospheric radiocarbon calibration to 45,000 yr. B.P.: late glacial fluctuations and cosmogenic isotope production.  Science 279: 1187-90.  1998.

--labs which perform radiocarbon testing are compared; they produce similar dates; some small differences exist

International study group.  An interlaboratory comparison of radiocarbon measurements in tree rings.  Nature 298: 619-23.  1982.

Sm-Nd

--Canadian strata dated at 2.5 billion years old

Sm-Nd and Rb-Sr chronolgy of continental crust formation.  Science 200: 1003-11.  1978.

--Indian strata dated at 3.8 billion years old

Basu, A.  Eastern Indian 3800 million year old crust and early mantle differentiation.  Science 212: 1502-5.  1981.

--analysis of isotopes and applications to crustal formation

Carlson, R.  Sm-Nd and isotopic systematics of the bimodal suite, ancient gneiss complex, Swaziland.  Nature 305: 701-3.  1983.

--Western Australian strata are dated at 3.2 million years old

Claoue-Long, J.  Revised Sm-Nd systematics of Kambbalda greenstones, Western Australia. Nature 307:697-701.  1984.

OTHER

--dating strata with hominid fossils

Valladas, H.  Thermoluminsecence dating of Mousterian “Proto-Cro-Magnon” remains from Israel and the origin of modern man.  Nature 334: 614-6.  1988.

--analysis of strata

Griffiths, D.  Trapped methyl radicals in chert.  Nature 300: 435-6.  1982.

--analysis of a meteorite

Patchett, P.  LuHf total-rock isochron for the eucrite meteorites.  Nature 288: 571-3.  1980.

--ice core dating

Fischer, Hubertus.  Ice core records of atmospheric CO2 around the last three glacial terminations.  Science 283: 1712-4.  1999.

--analysis of meteorites

Luck, Jean-Marc.  Re-Os systematics in meteorites: early chronology of the Solar System and age of the galaxy.  Nature 283: 256-9.  1980.

 

 

      Can relative dating be used in scientific studies?  Yes!

     Modern science depends on the testing of hypotheses and the analysis of data.  Scientists publish their data in refereed scientific journals.  Relative dating is used by professional scientists who have been trained in their field and publish their data in these respected scientific journals.  Below is a sample list of scientific papers which use relative dating techniques; this is only a tiny fraction of the actual number of papers that have been published.

      Although there are those who criticize all relative dating, in general they are not professional scientists, they are not trained in relevant fields of study, and they do not publish in respected scientific journals.

 

 

STRATIGRAPHY

--comparison of rock layers in regions where hominid fossils have been found

Cerling, T.E.  Tuffaceous marker horizons in the Koobi For a region and the Lower Omo Valley.  Nature 299: 216-21. 1982.

--comparison of rock layers in regions where hominid fossils have been found

Bowen, Bruce.  Stratigraphical relationships of the Plio-Pleistocene deposits, East Rudolf, Kenya.  Nature 242: 391-3.  1973.

--analysis of rock layers in regions where hominid fossils have been found

Behrensmeyer, A.  Preliminary geological interpretation of a new hominid site in the Lake Rudolf Basin.  Nature 226: 225-6.  1970.

--analysis of rock layers in regions where hominid fossils have been found

Brown, F.  Stratigraphical significance of the Tulu Bor Tuff of the Koobi For a Formation.  Nature 299: 212-5.  1982.

--analysis of the date of the formation of caves in which hominid fossils were found

Partridge, T.  Geomorphological dating of cave openings at Makapansgat, Sterfontein, Swartkrans and Taung.  Nature 246: 75-8.  1973.

--analysis of rock layers in regions which are earlier than those in which hominid fossils have been found

Kalb, Jon.  Geology and stratigraphy of Neogene depostis, Middle Awash Valley, Ethiopia.  Nature 298: 17-24.  1982.

--analysis of rock layers in regions where hominid fossils have been found

Vondra, Carl.  Preliminary stratigraphical studies of the East Rudolf Basin, Kenya.  Nature 231: 245-7.  1971.

--materials in rock strata indicate extraterrestrial impact

Schultz, P.  A 3.3 Ma impact in Argentina and possible consequences.  Science 282:2061-3.  1998.

--North American and African strata which were once joined are compared

Rohr, K.  Mesozoic complementary crust in the North Atlantic.  Nature 283: 758-61.  1980.

--Analysis of early Paleozoic strata

Bond, Gerard.  Thermal subsidence and eustasy in the Lower Palaeozoic miogeocline of western North America.  Nature: 306: 774-9. 1983.

VERTEBRATE FAUNA

--analysis of the different vertebrate faunas in rock strata which include hominid fossils

Maglio, Vincent.  Vertebrate Faunas and chronology of Hominid-bearing sediments east of Lake Rudolf, Kenya.  Nature 239: 379-84.  1972.

--vertebrate fauna are used to date strata containing hominid fossils

Boaz, N. T.  Faunal age of the Usno, Shungura B and Hadar Formations, Ethiopia.  Nature 300: 633-5.  1982.

--analysis of the different vertebrate faunas in rock strata which include hominid fossils

Maglio, Vincent.  Vertebrate faunas from the Kubi Algi, Koobi For a and Ileret areas, East Rudolf, Kenya.  Nature 231: 248-9.  1971.

--analysis of the different vertebrate faunas in rock strata which include hominid and primate fossils

Kalb, Jon.  Fossil mammals and artefacts from te Middle Awash Valley, Ethiopia.  Nature 298: 25-9.  1982.

--analysis of the suid species (pigs and relatives) in rock strata; applications to the dating hominid fossils

White, T.D.  Suid Evolution and correlation of African hominid localities.  Science 198: 13-21.  1977.

--analysis of the bovid species (cows and relatives) in rock strata; applications to the dating hominid fossils

Vrba, E.S. Some evidence of chronology and palaeoecology of Sterkfontein, Swartkrans and Kromdraai from the fossil Bovidae.  Nature 254: 301-4.  1975.

--analysis of the mammal fossils in dated strata

Behrensmeyer, Anna.  Late Pliocene faunal turnover in the Turkana Basin, Kenya and Ethiopia.  Science 278: 1589-93.  1997.

--analysis of the different vertebrate faunas in rock strata which include hominid fossils

Taieb, M.  Geological and palaeontological background of Hadar hominid site, Afar, Ethiopia.  Nature 260: 289-93.  1976.

--analysis of mammalian fossils; applications to dating hominid fossils

Brown, Francis.  Tulu Bor tuff at Koobi For a correlated with the Sidi Hakoma tuff at Hadar.  Nature 300: 631-3.  1982.

--analysis of the different vertebrate faunas in rock strata which include hominid fossils

Sondaar, Paul.  The Geochelone faunas of the Indonesian archipelago and their paleogeographical and biostratigraphical significance.  Mod. Quaternary Res. SE asia 6: 111-120.  1981.

--analysis of mammalian fauna of the Miocene

Barry, John.  Neogene mammalian faunal change in southern Asia: correlations with climatic, tectonic, and eustatic events.  Geology 13: 637-40.  1985.

--analysis of Devonian fish, arthropods, and spores from early plants

Cloutier, Richard.  Biostratigraphy of the Upper Devonian Escuminac Formation eastern Quebec, Canada: a comparative study based on microspores and fishes.  Rev. Palaeobotany and Palynology 93: 191-215.  1996.

--analysis of aquatic and terrestrial fauna of Late Tertiary

Rasanen, Matti.  Late Miocene Tidal deposits in the Amazonian foreland basin.  Science 269: 386-9.  1995.

--analysis of dinosaur faunas just before K/T boundary

Sheehan, Peter.  Sudden extinction of the dinosaurs: Latest Cretaceous, Upper Great Plains, U.S.A.  Science 254: 835-8.  1991.

--analysis of mammalian fauna

Pilbeam, David.  Geology and palaeontology of Neogene strata of Pakistan.  Nature 270: 684-9.  1977.

INVERTEBRATE FAUNA

--analysis of mollusc species present in different rock strata

Williamson, P.G.  Palaeontological documentation of speciation in Cenozoic molluscs from Turkana Basin.  Nature 295: 437-42.  1981.

--analysis of shellfish

Glover, I.  Leang Burung 2: an Upper Paleolithic rock shelter in South Sulawesi, Indonesia.  Mod. Quaternary Res. SE Asia 6: 1-38.  1981.

--analysis of shellfish

Glover, I.  Leang Burung 2: shell analysis.  Mod. Quaternary Res. SE Asia 6: 45-50.  1981.

 

 

MICROFOSSILS

--the dating of a strata containing a hominid fossil is examined in light of planktonic foraminifera microfossils

Siesser, William.  Micropalaeontological re-assessment of the age of Pithecanthropus mandible C from Sangiran, Indonesia.  Mod. Quaternary Res. SE Asia 4: 25-30.  1978.

--description of the algal microfossils found in hominid bearing strata

Johnson, Gary.  Cainozoic lacustrine stromatolites from hominid-bearing sediments East of Lake Rudolf, Kenya.  Nature 247: 520-2.  1974.

--analysis of rock strata and diatom microfossils

Williams, M.A.  Plio-Pleistocene environments at Gadeb prehistoric site, Ethiopia.  Nature 282: 29-32.  1979.

--nannofossil stratigraphy used to date strata where hominid fossils have been found

Sarna-Wojcicki.  Ages of tuff beds at East African early hominid sites and sediments in the Gulf of Aden.  Nature 313: 306-8.  1985.

POLLEN

--pollen analyzed to provide information on climate

Bonnefile, R.  Evidence for a cooler and drier climate in the Ethiopian uplands towards 2.5 Myr ago.  Nature 303:487-91.  1983.

--analysis of the pollen classes present in K/T strata

Leffingwell, Harry.  Palynology of the Lance (Late Cretaceous) and Fort Union (Paleocene) formations of the Type Lance Area, Wyoming.  Geological Society of America Special Paper 127.

--analysis of the pollen classes present in K/T strata

Franczyk, Karen.  Sedimentology, mineralogy, palynology, and depositional history of some uppermost Cretaceous and lowermost Tertiary rocks along the Utah Book and Roan cliffs east of the Green River.  U.S. Government printing office: 1991—573-049/26,020 Region No. 8.

--analysis of pollen from the Permian/Triassic boundary

Poort, Ruud.  Aspects of Permian palaeobotany and palynology.  XVII.  Conifer extinction in Europe at the Permian-Triassic junction: morphology, ultrastructure, and geographic/stratigraphic distribution of Nuskoisporites dulhuntyi (prepollen of Ortiseia, Walchiaceae).  Rev. of Palaeobotany & Palynology 97: 9-39.  1997.

--analysis of Holocene pollen

Maloney, Bernard.  A pollen diagram from Tao Sipinggan, a lake site in the Batak highlands of North Sumatra, Indonesia.  Mod. Quaternary Res. SE Asia 6: 57-76 (1981).

Paleomagnetostratigraphy

--a study of Javan strata

Semah, F.  A paleomagnetic study of Plio-Pleistocene sediments from Sangiran and Simo (Central Java): Initial results.  Mod. Quaternary Res. SE Asia 6: 103-110.  1981.

--a strata is determined to be of Pliocene age using palaeomagnetostratigraphy

Heller, Friedrich.  Magnetostratigraphal dating of loess deposits in China.  Nature 300: 431-3.  1982.

--strata assigned to the K/T boundary are compared

Butler, Robert.  Magnetostratigraphy of the Cretaceous-Tertiary boundary in the San Juan Basin, New Mexico.  Nature 267: 318-23.  1977.

--a hominid bearing strata is dated using stratigraphy, foraminiferan microfossils, and paleomagnetic studies

Sartono, S.  The Age of Homo modjokertensis.  Mod. Quarternary Res. SE Asia 6: 91-102.  1981.

OXYGEN ISOTOPES

--500,000 year record of oxygen isotope fluctuations in marine sediments

McManus, Jerry.  A 0.5 million-year record of millennial-scale climate variability in the North Atlantic.  Science 283: 971-4.  1999.

--870,000 year record of oxygen isotope fluctuations in marine sediments

Shackleton, Nicholas.  Oxygen isotope and Palaeomagnetic Stratigraphy of Equatorial Pacific core V28-238: oxygen isotope temperatures and ice volumes and ice volumes on a 105 and 106 year scale.  Quaternary Research 3: 39-55.  1973.

--750,000 year record of oxygen isotope fluctuations in marine sediments

Nelson, C.  Near-synchroneity of New Zealand alpine glaciations and Northern Hemisphere continental glaciations during the past 750 kyr.  Nature 318: 361-3.  1985.

--analysis of oxygen isotopes in fossil corals

Dunbar, Robert.  Stable isotopes in a branching coral monitor seasonal temperature variation.  Nature 293: 453-5.  1981.

--oxygen isotope record of middle Pliocene

Keigwin, L.  Middle Pliocene climatic change in the western Mediterranean from faunal and oxygen isotopic trends.  Nature 282: 294-6.  1979.

--oxygen isotope record of the Late Pliocene

Shackleton, N.  Oxygen isotope calibration of the onset of ice rafting and history of glaciation in the North Atlantic region. Nature  620-4. 1984.

--oxygen isotope record of lake sediments in East Africa in the Pleistocene

Cerling, T.  Isotopic evidence for dramatic climatic changes in East Africa during the Pleistocene.  Nature 267: 137-8.  1977.

OTHER RADIOISOTOPES

--isotopic content of foraminifera analyzed

Nelson, Bruce.  Rapid change in strontium isotopic composition of sea water before the Cretaceous/Tertiary boundary.  Nature 351: 644-7.  1991.

--continental uplift inferred from strontium levels

Caldeira, Ken.  Enhanced Cenozoic chemical weathering and the subduction of pelagic carbonate.  Nature 357: 578-81.  1992.

--nature of the atmosphere inferred from isotope levels

Collerson, Kenneth.  Evolution of the continents and the atmosphere inferred from Th-U-Nb systematics of the depleted mantle.  Science 283: 1519-21.  1999.

--isotope ratios in fossil teeth and relation to climate

Cerling, Thure.  Global vegetation change through the Miocene/Pliocene boundary.  Nature 389: 153-7.  1997.

--salinity and nature of estuarine environments inferred from isotope levels

Ingram, B.  Strontium isotopic composition of estuarine sediments as paleosalinity-paleoclimate indicator.  Science 255: 68-71.

--analysis of extraterrestrial material accumulating during the Ordovician

Schmitz, Birger.  Accretion rates of meteorites and cosmic dust in the Early Ordovician.  Science 278: 88-90.  1997.

AMINO ACID RACEMIZATION

--chronology established through analysis of planktonic foraminifera

Macko, S. Amino acid epimerization in planktonic foraminifera suggests slow sedimentation rates for Alpha Ridge, Arctic Ocean.  Nature 322: 730-2.  1986.

--subtropical temperatures determined

Miller, Gifford.  Low-latitude glacial cooling in the Southern Hemisphere from amino-acid racemization in emu eggshells.  Nature 385: 241-4.  1997.

 

COMPARISONS OF ABSOLUTE DATES

 

How accurate are the dates which are produced by absolute dating?  Below are some examples of sites analyzed by different researchers and different techniques.  Please compare the dates in each specific colored box (keeping in mind the standard deviation). 

YOU DO NOT HAVE TO UNDERSTAND THE DATING TECHNIQUES LISTED BELOW (this is beyond the scope of this course), SIMPLY EXAMINE WHETHER DIFFERENT SAMPLES, OFTEN ANALYZED BY DIFFERENT RESEARCHERS USING DIFFERENT TECHNIQUES, OBTAIN EQUIVALENT DATES.  Each different color represents a different set of samples and should be considered separately.

 

 

 

Region Dated

 

DATING TECHNIQUE

 

AGE (years)

 

STANDARD DEVIATION

(years)

 

PERFORMED BY

 

Age of Earth

 

Pb-U

 

4,530,000,000

 

40,000,000

 

Ulrych 1967

 

 

 

 

 

4,550,000,000

 

70,000,000

 

Murthy 1962

 

 

 

 

 

4,530,000,000

 

30,000,000

 

Ostic, 1963

 

West Greenland; Godthaab

 

Rb-Sr

 

2,530,000,000

 

30,000,000

 

Moorbath, 1981

 

 

 

Rb-Sr

 

2,520,000,000

 

30,000,000

 

Pankhurst, 1973

 

 

 

Pb-Pb

 

2,580,000,000

 

80,000,000

 

Moorbath, 1981

 

 

 

U-Pb

 

2,530,000,000

 

30,000,000

 

Baadsgaard, 1976

 

South Africa; Komati Formation

 

Rb-Sr

 

3,430,000,000

 

20,000,000

 

Jahn, 1974 (no, not me)

 

 

 

Ar-Ar

 

3,490,000,000

 

10,000,000

 

Lopez Martinez 1984

 

 

 

Ar-Ar

 

3,410,000,000

 

30,000,000

 

Lopez Martinez 1984

 

 

 

Ar-Ar

 

3,420,000,000

 

10,000,000

 

Lopez Martinez 1984

 

 

 

Ar-Ar

 

3,330,000,000

 

20,000,000

 

Lopez Martinez 1984

 

 

 

Ar-Ar

 

3,450,000,000

 

10,000,000

 

Lopez Martinez 1984

 

 

 

Pb-Pb

 

3,460,000,000

 

70,000,000

 

Brevart, 1986

 

Laetoli Koobi Fora (hominid fossils)  tuff unit 131

 

K/Ar

 

1,830,000

 

20,000

 

Kurtis, 1975

 

K/Ar

 

1,840,000

 

70,000

 

Kurtis, 1975

 

 

 

K/Ar

 

1,850,000

 

30,000

 

Kurtis, 1975

 

 

 

K/Ar

 

1,730,000

 

30,000

 

Kurtis, 1975

 

 

 

K/Ar

 

1,830,000

 

30,000

 

Kurtis, 1975

 

 

 

K/Ar

 

1,810,000

 

20,000

 

Kurtis, 1975

 

Laetoli Koobi Fora tuff unit 105

 

K/Ar

 

1,500,000

 

20,000

 

Kurtis, 1975

 

K/Ar

 

1,650,000

 

20,000

 

Kurtis, 1975

 

 

 

K/Ar

 

1,680,000

 

10,000

 

Kurtis, 1975

 

 

 

K/Ar

 

1,560,000

 

20,000

 

Kurtis, 1975

 

 

 

K/Ar

 

1,610,000

 

20,000

 

Kurtis, 1975

 

 

 

K/Ar

 

1,620,000

 

20,000

 

Kurtis, 1975

 

 

 

K/Ar

 

1,650,000

 

20,000

 

Kurtis, 1975

 

 

 

            3 samples contaminated with detritus; yielded ages of 2,010,000 to 2,530,000

 

 

 

Apollo 11 moon sample #10072

 

Ar-Ar

 

3,490,000,000

 

50,000,000

 

Turner, 1970

 

 

 

Ar-Ar

 

3,520,000,000

 

40,000,000

 

Guggisberg, 1979

 

 

 

Ar-Ar

 

3,570,000,000

 

50,000,000

 

Guggisberg, 1979

 

 

 

Ar-Ar

 

3,560,000,000

 

60,000,000

 

Guggisberg, 1979

 

 

 

Ar-Ar

 

3,580,000,000

 

50,000,000

 

Guggisberg, 1979

 

 

 

Ar-Ar

 

3,550,000,000

 

50,000,000

 

Guggisberg, 1979

 

 

 

Rb-Sr

 

3,570,000,000

 

50,000,000

 

Papanastassiou, 1977

 

 

 

Sm-Nd

 

3,570,000,000

 

30,000,000

 

Papanastassiou, 1977

 

Apollo 15 moon sample #15555

 

Ar-Ar

 

3,290,000,000

 

50,000,000

 

Alexander 1972

 

 

 

Ar-Ar

 

3,250,000,000

 

60,000,000

 

York, 1972

 

 

 

Ar-Ar

 

3,280,000,000

 

60,000,000

 

York, 1972

 

 

 

Ar-Ar

 

3,240,000,000

 

60,000,000

 

Husain 1972

 

 

 

Ar-Ar

 

3,190,000,000

 

20,000,000

 

Podosek, 1972

 

 

 

Ar-Ar

 

3,270,000,000

 

20,000,000

 

Podosek, 1972

 

 

 

Ar-Ar

 

3,240,000,000

 

30,000,000

 

Podosek, 1972

 

 

 

Rb-Sr

 

3,230,000,000

 

80,000,000

 

Murthy, 1972

 

 

 

Rb-Sr

 

3,270,000,000

 

90,000,000

 

Bird, 1972

 

 

 

Rb-Sr

 

3,250,000,000

 

40,000,000

 

Papanastassiou, 1973

 

Meteorite Allende

 

Ar-Ar

 

4,520,000,000

 

20,000,000

 

Dominik 1978

 

 

 

Ar-Ar

 

4,530,000,000

 

20,000,000

 

Dominik 1978

 

 

 

Ar-Ar

 

4,480,000,000

 

20,000,000

 

Jessberger 1980

 

 

 

Ar-Ar

 

4,550,000,000

 

30,000,000

 

Jessberger 1980

 

 

 

Ar-Ar

 

4,570,000,000

 

30,000,000

 

Jessberger 1980

 

 

 

Ar-Ar

 

4,500,000,000

 

20,000,000

 

Jessberger 1980

 

 

 

Ar-Ar

 

4,560,000,000

 

50,000,000

 

Jessberger 1980

 

Brasil cave strata with signs of human habitation; Layer DIII

 

C-14

 

7,750

 

80

 

Guidon, 1986

 

C-14

 

7,640

 

140

 

Guidon, 1986

 

Brasil cave strata; Layer BI

 

C-14

 

31,700

 

830

 

Guidon, 1986

 

 

 

C-14

 

32,160

 

1,000

 

Guidon, 1986

 

Cretaceous/Tertiary Boundary

 

K/Ar

 

64,600,000

 

3,000,000

 

Drake, 1983

 

 

 

Ar/Ar

 

64,940,000

 

110,000

 

Swisher

 

 

 

Ar/Ar

 

65,000,000

 

80,000

 

Swisher

 

 

 

Ar/Ar

 

64,980,000

 

50,000

 

Swisher

 

 

 

Ar/Ar

 

64,380,000

 

80,000*

 

Swisher

 

 

 

Ar/Ar

 

64,480,000

 

220,000*

 

Swisher

 

 

 

Ar/Ar

 

65,070,000

 

100,000

 

Swisher

 

 

 

Ar/Ar

 

65,010,000

 

80,000

 

Swisher

 

 

 

Ar/Ar

 

64,600,000

 

400,000

 

Swisher

 

 

 

Ar/Ar

 

65,200,000

 

1,200,000

 

Swisher

 

 

 

Ar/Ar

 

64,750,000

 

280,000

 

Hall, 1991

 

 

 

K/Ar

 

64,000,000

 

700,000

 

Gillot, 1991

 

 

 

Ar/Ar

 

64,910,000

 

120,000

 

WIlliams

 

 

 

Ar/Ar

 

64,480,000

 

80,000

 

Izett, 1991

 

 

 

Ar/Ar

 

64,570,000

 

23,000

 

Izett, 1991

 

 

 

K/Ar

 

64,600,000

 

500,000

 

Izett, 1991

 

 

 

Ar/Ar

 

64,800,000

 

70,000

 

Izett, 1991

 

 

 

Ar/Ar

 

65,800,000

 

600,000

 

Izett, 1991

 

 

 

Ar/Ar

 

64,700,000

 

600,000

 

Izett, 1991

 

 

 

 

Ar/Ar

 

65,700,000

 

1,000,000

 

Izett, 1991

 

 

 

Rb/Sr

 

63,700,000

 

600,000

 

Dairymple, 1993

 

 

 

U/Pb

 

64,400,000

 

400,000

 

Dairymple, 1993

 

 

 

Rb/Sr

 

63,900,000

 

600,000

 

Dairymple, 1993

 

 

 

 

U/Pb

 

64,300,000

 

800,000

 

Dairymple, 1993