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in review

Guy, B., Gutzmer, J., Kaufman, A.J., Lin, Y., Fogel, M., and Beukes, N.J. (in review) A multiple-sulfur and organic carbon isotope record from non-conglomeratic sedimentary rocks of the Mesoarchean Witswatersrand Supergroup, South Africa.  Precambrian Research.

Zelanko, P., Yu, Z., Bebout, G. and Kaufman, A.J. (in review) Early Holocene outburst floods and climate oscillations at Silver Lake, New Jersey.  Palaeogeography, Palaeoclimatology, Palaeoecology.

Loyd, Sean J., Marenco, Pedro J., Hagadorn, James W., Lyons, Timothy W., Kaufman, Alan J., Sour-Tovar, F. and Corsetti, Frank A. (in review) Local δ34S variability in ~580Ma carbonates of northwestern Mexico and the Neoproterozoic marine sulfate reservoir.  Precambrian Research.

Loyd, S.J., Marenco, P.J., Hagadorn, J.W., Lyons, T.W., Kaufman, A.J., Sour-Tovar, F. and Corsetti, F.J. (in review) Sustained low sulfate concentration in the Neoproterozoic to Cambrian ocean: insights from carbonates of northwestern Mexico and eastern California.  Earth and Planetary Science Letters.

Thompson, C.K.*, Kah, L.C., and Kaufman, A.J. (in review) Did ventilation of euxinic oceans herald the end of Ordovician greenhouse climate?  Nature Geoscience.



Martin, A.J., Burgy, K.D., Kaufman, A.J., Gehrels, G.E. (2011) Stratigraphic and tectonic implications of field and isotopic constraints on depositional ages of Proterozoic Lesser Himalayan rocks in central Nepal.  Precambrian Research 185: 1-17. download pdf

Xiao, S., McFadden, K.A., Peek, S.*, Kaufman, A.J., Zhou, C., Jiang, G., and Hu, J. (in press) Implications of integrated chemostratigraphy and basin architecture of the Doushantuo Formation for Ediacaran stratigraphic correlation and ocean redox models.  Precambrian Research 192-195: 125-141.  download pdf

Oduro, H.*, Harms, B.*, Sintim, H.O., Kaufman, A.J., Cody, G., and Farquhar, J. (2011) Evidence of magnetic isotope effects during thermochemical sulfate reduction.  Proceedings of the National Academy of Sciences 108: 17635-17638.  download pdf

 Shen, B., Xiao, S., Bao, H., Kaufman, A.J., Zhou, C., Yuan, X. (2011) Carbon, sulfur, and oxygen isotope evidence for a strong depth gradient and oceanic oxidation after the Ediacaran Hankalchough glaciation.  Geochimica et Cosmochimica Acta 75: 1357-1373.  download pdf



Hebert, C.L., Kaufman, A.J., Renniston-Dorland, Martin, A.J. (in press) Radiometric and stratigraphic constraints on terminal Ediacaran (post-Gaskiers) glaciation and metazoan evolution.  Precambrian Research 182: 402-412. download pdf

Kendall, B., Reinhard, C.T., Lyons, T.W., Kaufman, A.J., Poulton, S.W., Anbar, A. (2010) Pervasive oxygenation along Late Archean ocean margins.  Nature Geosciences 3: 647-652.  download pdf

Shen, B., Xiao, S., Zhou, C., Kaufman, A.J., Yuan, X. (2010) Carbon and sulfur isotope chemostratigraphy of the Neoproterozoic Quanji Group of the Chaidam Basin, NW China: Basin stratification in the aftermath of an Ediacaran glaciation postdating the Shuram event?  Precambrian Research 177: 241-252.  download pdf

Guo, Z., Li, Z., Farquhar, J., Kaufman, A.J., Wu, N., Li, C., Dickerson, R.R., Wen, T.,Wang, P. (2010) Identification of sources of atmospheric sulfate by sulfur isotope and SEM measurements.   Journal of Geophysical Research 115.  download pdf



Kaufman, A.J., Sial, A.N., Frimmel, H.E., Misi, A. (2009) Neoproterozoic to Cambrian paleoclimatic events in southwestern Gondwana.  In Neoproterozoic-Cambrian Tectonics, Global Change, and Evolution: A Focus on Southwestern Gondwana (Eds. Gaucher, C., Sial, A.N., Frimmel, H.E. and Halverson, G.P.).  Developments in Precambrian Geology 16: 369-388.  download pdf

Garvin, J.*, Buick, R., Anbar, A.D., Arnold, G.L., Kaufman, A.J., Response to Analysis of Archean nitrogen isotopic data.  Science E-letter.  download pdf

Klochko, K., Cody, G., Tossell, J.A., Dera, P., Kaufman, A.J. (2009) Re-evaluating boron speciation in biogenic calcite and aragonite using 11B MAS NMR. Geochimica et Cosmochimica Acta 73: 1890-1900.  download pdf

Ono, S., Kaufman, A.J., Farquhar, J., Sumner, D.Y., Beukes, N.J. (2009) Lithofacies control on multiple-sulfur isotope records and Neoarchean sulfur cycles. Precambrian Research 169: 58-67.  download pdf

Guo, Q., Strauss, H., Kaufman, A.J., Schroder, S., Gutzmer, J., Wing, B., Baker, M.A., Bekker, A., Kim, S.-T., Farquhar, J. (2009) Reconstructing Earth’s surface oxidation across the Archean-Proterozoic transition. Geology 37: 399-402.  download pdf

Shen, Y., Farquhar, J., Masterson, A., Kaufman, A.J., Buick, R. (2009) Evaluating the role of microbial sulfate reduction in the early Archean using quadruple isotope systematics. Earth and Planetary Science Letters 279: 383-391.  download pdf

Garvin, J., Buick, R., Anbar, A.D., Arnold, G.L., Kaufman, A.J. (2009) Isotopic evidence for an aerobic nitrogen cycle in the latest Archean. Science 323: 1045-1048.  download pdf

Johnston, D.T., Farquhar, J., Summons, R.E., Shen, Y., Kaufman, A.J., Masterson, A.L., Canfield, D.E. (2009) Mid-Proterozoic sulfur and carbon isotope biogeochemistry: insights from the McArthur Basin. Geochimica et Cosmochimica Acta 72: 4278-4290. download pdf 

Rooker, J.R., Secor, D.H., DeMetrio, G., Kaufman, A.J., Rios, A.B., Rodriquez-Marin, E., Ti?ina, V. (2009) Evidence of trans-Atlantic movement and natal homing of bluefin tuna from stable isotopes in otoliths. Marine Ecology Progress Series 368: 231-239.  download pdf



Marenco, P.J., Corsetti, F.A., Hammond, D.E, Kaufman, A.J., and Bottjer, D.J. (2008) Oxidation of pyrite during extraction of carbonate associated sulfate. Chemical Geology 247: 124-132. download pdf

Shen, B., Xiao, S., Kaufman, A.J., Bao, H., Zhou, C., and Wang, H. (2008) Stratification and mixing of a Neoproterozoic post-glacial ocean: Evidence from carbon and sulfur isotopes in a cap dolostone from northwest China.  EPSL 265: 209-228. download pdf



Kaufman, A.J. (2007) Slush find.  Nature 450: 807-808.  download pdf

Kaufman, A.J., Johnston, D.J., Farquhar, J., Masterson, A.L, Lyons, T.W., Bates, S., Anbar, A.D., Arnold, G.L., Garvin, J., and Buick, R. (2007) Late Archean biospheric oxygenation and atmospheric evolution.  Science 317: 1900-1903.  
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Anbar, A.D., Duan, Y., Lyons, T.W., Arnold, G.L., Kendall, B., Creaser, R.A., Kaufman, A.J., Gordon, G.W., Garvin, J., and Buick, R. (2007) A whiff of oxygen before the Great Oxidation Event?  Science 317: 1903-1906. download pdf

Schiffbauer, J.D., Leiming Yin, Bodnar, R.J., Kaufman, A.J., Meng, F., Hu, J., Shen, B., Yuan, X., and Xiao, S. (2007) Ultrastructural and geochemical characterization of Archean-Paleoproterozoic graphite particles: Implications for recognizing traces of life in highly metamorphosed rocks.  Astrobiology 7(4): 684-704.  download pdf

Jiang, G., Kaufman, A.J., Christie-Blick, N., Zhang, S. and Wu, H. (2007) Carbon isotope variability across the Ediacaran Yangtze platform in South China: Implications for a large surface-to-deep ocean d13C gradient.  Earth & Planetary Science Letters 261: 303-320.  
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Bekker, A. and Kaufman, A.J. (2007) Oxidative forcing of global climate change: A biogeochemical record across the oldest Proterozoic ice age in North America.  Earth & Planetary Science Letters 258: 486-499.  download pdf

Farquhar, J., Peters, M., Johnston, D.J., Strauss, H., Masterson, A., Weichert, U. and Kaufman, A.J. (2007) Isotopic evidence for Mesoarchean anoxia and changing atmospheric sulfur chemistry.  Nature 499: 706-711.  download pdf

France, C.A.M., Zelanko, P. M., Kaufman, A.J., and Holtz, T.R. (2007) Carbon and nitrogen isotopic analysis of Pleistocene mammals from the Saltville Quarry (Virginia, USA): Implications for trophic relationships. Palaeogeography, Palaeoclimatology, Palaeoecology 249:271-282.  download pdf

Kaufman, A.J., Sial, A.N., and Ferreira, V.P. (2007) Preface to Special Issue of Chemical Geology on Precambrian Chemostratigraphy in honor of the late William T. Holser.  Chemical Geology 237: 1-4. download pdf

Misi, A., Kaufman, A.J., Azmy, K, Gaucher, C., Powis, K., Veizer, J., Boggiani, P.C., Teixeira, J.B.G., Sanches, A.L., and Iyer, S.S. (2007) Chemostratigraphic correlation of Neoproterozoic successions in South America.  Chemical Geology 237: 143-167. download pdf

Kaufman, A.J., Corsetti, F.A., and Varni, M.A. (2007) The effect of rising atmospheric oxygen on carbon and sulfur isotope anomalies in the Neoproterozoic Johnnie Formation, Death Valley, USA.  Chemical Geology 237: 47-63. download pdf


Azmy, K., Kaufman, A.J., Misi, A., and de Oliviera, T.F. (2006) Isotope stratigraphy of the Lapa Formation, Sao Francisco Basin, Brazil: Implications for Late Neoproterozoic glacial events in South America.  Precambrian Research 149: 231-248.
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Klochko, K., Kaufman, A.J., Yao, Wengsheng, Byrne, R.H. and Tossell, J.A. (2006) Experimental measurment of boron isotope fractionation in seawater.  Earth and Planetary Science Letters 248: 276-285. download pdf

Bekker, A., Karhu, J.A. and Kaufman, A.J. (2006) Carbon isotope record of the onset of the Lomagundi carbon isotope excursion in the Great Lakes area, North American. Precambrian Research 148:145-180. download pdf

Kaufman, A.J., Jiang, G., Christie-Blick, N., Banerjee, D. and Rai, V. (2006) Stable isotope record of the terminal Neoproterozoic Krol platform in the Lesser Himalayas of northern India. Precambrian Research 147, 156–185. download pdf

Byrne, R.H., Yao, W., Klochko, K., Tossell, J.A. and Kaufman, A.J. (2006) Experimental evaluation of the isotope exchange equilibrium 10B(OH)3 + 11B(OH)4- = 11B(OH)3 + 10B(OH)4- in aqueous solutions. Deep Sea Research Part I 53, 684-688. download pdf 



Johnston, D.T., Farquhar, J., Wing, B.A., Kaufman, A.J., Canfield, D.E. and Habicht, K. (2005) Multiple sulfur isotope fractionations in biological systems. American Journal of Science 305: 645-660.
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Johnston, D.T., Wing, B.A., Farquhar, J., Kaufman, A.J., Strauss, H., Lyons, T.W., Kah, L.C. and Canfield, D.E. (2005) Active microbial sulfur disproportionation in the Mesoproterozoic. Science 310: 1477-1479. download pdf

Kaufman, A.J. (2005) The calibration of Ediacaran time. Science 308 (5718): 59-60. download pdf

Corsetti, F.A. and Kaufman, A.J. (2005) The relationship between the Neoproterozoic Noonday Dolomite and the Ibex Formation: New observations and their bearing on ‘snowball Earth’. Earth-Science Reviews 73: 63-78. download pdf

Bekker, A., Kaufman, A.J., Karhu, J.A. and Eriksson, K.A. (2005) Evidence for Paleoproterozoic cap carbonates in North America. Precambrian Research 137: 167-206. download pdf

Olcott, A.N., Sessions, A.L., Corsetti, F.A., Kaufman, A.J. and de Oliviera, T.F. (2005) Biomarker evidence for photosynthesis during Neoproterozoic glaciation. Science 310: 471-474. download pdf



Xiao, S., Bao, H., Wang, H., Kaufman, A.J., Zhou, C., Li, G., Yuan, X. and Ling, H. (2004) The Neoproterozoic Quruqtagh Group in eastern Chinese Tianshan: evidence for a post-Marinoan glaciation. Precambrian Research 130: 1-26.
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Bekker, A., Sial, A.N., Karhu, J.A., Ferreira, V.P., Noce, C.M., Romano, A.W., Kaufman, A.J., and Pimentel, M.M. (2003) Chemostratigraphy of carbonates from the Minas Supergroup, Quadrilatero Ferrifero, Brazil: implications for biogeochemical cycling of carbon in the early Paleoproterozoic. American Journal of Science 303: 865-904.
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Kaufman, A.J. and Xiao, Shuhai (2003) High CO2 levels in the Proterozoic atmosphere estimated from analyses of individual microfossils. Nature 424: 279-282. download pdf

Corsetti, F.A. and Kaufman, A.J. (2003) Stratigraphic investigations of carbon isotope anomalies and Neoproterozoic ice ages in Death Valley, California. Geological Society of America Bulletin 115: 916-932. download pdf

Jiang G., Christie-Blick N., Kaufman A.J., Banerjee, D.M. and Rai. V. (2003) Carbonate platform growth and cyclicity at a terminal Proterozoic passive margin, Infra Krol Formation and Krol Group, Lesser Himalaya, India. Sedimentology 50: 921-952.
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Alexander, B., Thiemens, M.H.. Farquhar, J., Kaufman, A.J., Savarino, J. and Delmas, R.J., 2003. East Antarctic ice core sulfur isotope measurements over a complete glacial-interglacial cycle. Journal of Geophysical Research 108(D24): xxx-xxx. download pdf

Bekker, A., Karhu, J.A., Eriksson, K.A. and Kaufman, A.J. (2003) Chemostratigraphy of Paleoproterozoic carbonate successions of the Wyoming Craton: tectonic forcing of biogeochemical change? Precambrian Research 120: 279-326. download pdf



Hurtgen, M.T., Arthur, M.A., Suits, N.S. and Kaufman, A.J. (2002) The sulfur isotopic composition of Neoproterozoic seawater sulfate: implications for a snowball Earth? Earth and Planetary Science Letters 203: 413-429.
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Ganqing Jiang, Christie-Blick, N., Kaufman, A.J., Banerjee, D.M. and Rai, V. (2002) Sequence stratigraphy of the Neoproterozoic Infra Krol Formation and Krol Group, Lesser Himalaya, India. Journal of Sedimentary Geology 72: 524-542. download pdf

Halverson, G.P., Hoffman, P.F., Schrag, D.P. and Kaufman, A.J. (2002) A major perturbation of the carbon cycle before the Ghaub glaciation (Neoproterozoic) in Namibia: a trigger mechanism for snowball Earth? Geochemistry, Geophysics, Geosystems 3(6): 10.1029/2001GC000244. dowload pdf



Bekker, A., Kaufman, A.J., Karhu, J.A., Beukes, N.J. Swart, Q. D., Coetzee, L.L. and Eriksson, K.A. (2001) Chemostratigraphy of the Paleoproterozoic Duitschland Formation, South Africa: implications for coupled climate change and carbon cycling. American Journal of Science 301: 261-285.
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Bartley, J.K., Semikhatov, M.A., Kaufman, A.J., Pope, M.C., Knoll, A.H. and Jacobsen, S.B. (2001) Global events across the Mesoproterozoic-Neoproterozoic boundary: C and Sr isotopic evidence from Siberia. Precambrian Research 111: 165-202. download pdf



Corsetti, F.A., Awramik, S.M., Pierce, D. and Kaufman, A.J. (2000) Using chemostratigraphy to correlate and calibrate unconformities in Neoproterozoic strata from the southern Great Basin of the United States. International Geology Review 42: 516-533.
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Hayes, J.M., Strauss, H. and Kaufman, A.J. (1999) The abundance of 13C in marine organic matter and isotopic fractionation in the global biogeochemical cycle of carbon during the past 800 Ma. Chemical Geology 161: 103-125.
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Jacobsen, S.B. and Kaufman, A.J. (1999) The Sr, C and O isotopic evolution of Neoproterozoic seawater. Chemical Geology 161: 37-57. download pdf

Kah, L.C., Sherman, A.G., Narbonne, G.M., Knoll, A.H. and Kaufman, A.J. (1999) d13C stratigraphy of the Proterozoic Bylot Supergroup, Baffin Island, Canada: implications for regional lithostratigraphic correlations. Canadian Journal of Earth Sciences 36: 313-332. download pdf

Myrow, P. and Kaufman, A.J. (1999) A newly-discovered cap carbonate above Varanger-aged glacial deposits in Newfoundland. Journal of Sedimentary Research 69: 784-793.



Hoffman, P.F., Schrag, D.P., Halverson, G.P. and Kaufman, A.J. (1998) An early snowball earth? Response. Science 282: 1645-1646. 

Saylor, B.Z., Kaufman, A.J., Grotzinger, J.P. and Urban, F. (1998) A composite reference section for terminal Proterozoic strata of southern Namibia. Journal of Sedimentary Research 68: 1223-1235.

Hoffman, P.F., Kaufman, A.J., Halverson, G.P. and Schrag, D.P. (1998) A Neoproterozoic snowball Earth. Science 281: 1342-1346.
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Hoffman, P.F., Kaufman, A.J. and Halverson, G.P. (1998) Comings and goings of global glaciations on a Neoproterozoic tropical platform in Namibia. GSA Today 8: 1-9. download pdf



Kaufman, A.J., Knoll, A.H. and Narbonne, G.M. (1997) Isotopes, ice ages, and terminal Proterozoic earth history. Proceedings of the National Academy of Sciences 94: 6600-6605.
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Xiao Shuhai, Knoll. A.H., Kaufman, A.J., Yin Leming and Yun Zhang (1997) Neoproterozoic fossils in Mesoproterozoic rocks? Chemostratigraphic resolution of a biostratigraphic conundrum from the North China Platform. Precambrian Research 84: 197-220. download pdf

Kaufman, A.J. (1997) An ice age in the tropics. Nature 386: 227-228.

Knoll, A.H., Kaufman, A.J., Semikhatov, M., Grotzinger, J.P. and Adams, W.R. (1997) Reply: Sizing up the sub-Tommotian unconformity in Siberia. Geology 25: 287.



Kaufman, A.J., Knoll, A.H., Semikhatov, M., Grotzinger, J.P., Jacobsen, S.B. and Adams, W.R. (1996) Isotopic chemostratigraphy of Precambrian-Cambrian boundary beds in the Western Anabar Region, Northern Siberia. Geological Magazine 133: 509-533.

Knoll, A.H., Kaufman, A.J., Semikhatov, M.A., Grotzinger, J.P. and Adams, W. (1996) Reply: Sizing up the sub-Tommotian unconformity in Siberia. Geology 24: 861-862.

Kaufman, A.J. (1996) Effects of contact metamorphism on banded iron-formation: Mineralogic and isotopic evidence. Precambrian Research (Special Issue on the Geology and Geochemistry of the Transvaal Supergroup) 79: 171-193.

Kaufman, A.J. and Danielson, A. (1996) Preface. Precambrian Research (Special Issue on the Geology and Geochemistry of the Transvaal Supergroup) 79: 1-2.

Pelechaty, S., Kaufman, A.J. and Grotzinger, J.P. (1996) Evaluation of d13C isotope stratigraphy for intrabasinal correlation: Data from Vendian strata of the Olenek uplift and Kharaulakh Mountains, Siberian platform, Russia. The Bulletin of the Geological Society of America 108: 992-1003.

Kaufman, A.J. and Corsetti, F.A. (1996) Reply: Chemostratigraphy of Neoproterozoic-Cambrian Units, White-Inyo Region, Eastern California: Implications for Global Correlation and Faunal Distribution. Palios 11: 86-89.

Smith, L.H., Kaufman, A.J., Knoll, A.H. and Link, P.K. (1996) Reply: Chemostratigraphy of the terminal Proterozoic Pocatello Formation and Lower Brigham Group, Southeastern Idaho and Northern Utah. Geological Magazine 133: 347-349.



Grotzinger, J.P., Bowring, S.A., Saylor, B.Z., and Kaufman, A.J. (1995) Biostratigraphic and geochronologic constraints on early animal evolution. Science 270: 598-604.
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Knoll, A.H., Kaufman, A.J., Semikhatov, M.A., Grotzinger, J.P. and Adams, W.R. (1995) Sizing up the sub-Tommotian unconformity in Siberia. Geology 23: 1139-1143.

Kaufman, A.J. and Knoll, A.H. (1995) Neoproterozoic variations in the carbon isotopic composition of seawater: Stratigraphic and biogeochemical implications. Precambrian Research 73: 27-49.
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Knoll, A.H., Grotzinger, J.P., Kaufman, A.J. and Kolosov, P. (1995) Integrated chronostratigraphy of the terminal Proterozoic successions of the Olenek Uplift, northern Siberia. Precambrian Research 73: 251-270.

Knoll, A.H., Kaufman, A.J. and Semikhatov, M.A. (1995) The carbon-isotopic composition of Proterozic carbonates: Riphean successions from the Anabar Massif and Turukhansk Uplift, Siberia. American Journal of Science 295: 823-850.



Narbonne, G.M., Kaufman, A.J. and Knoll, A.H. (1994) Integrated carbon isotope and biostratigraphy of the upper Windemere Group, MacKenzie Mountains, N.W. Territories, Canada. The Bulletin of the Geological Society of America 106: 1281-1292.

Smith, L.H., Kaufman, A.J., Knoll, A.H. and Link, P.K. (1994) Chemostratigraphy of the terminal Proterozoic Pocatello Formation and Lower Brigham Group, Southeastern Idaho and Northern Utah. Geological Magazine 131: 301-314.

Corsetti, F.A. and Kaufman, A.J. (1994) Chemostratigraphy of Neoproterozoic-Cambrian Units, White-Inyo Region, Eastern California: Implications for Global Correlation and Faunal Distribution. Palios 9: 211-219.



Kaufman, A.J., Jacobsen, S.B. and Knoll, A.H. (1993) The Vendian record of C- and Sr-isotopic variations: Implications for tectonics and paleoclimate. Earth and Planetary Science Letters 120: 409-430.


Kaufman, A.J., Knoll, A.H. and Awramik, S.M. (1992) Biostratigraphic and chemostratigraphic correlation of Neoproterozoic sedimentary successions: Upper Tindir Group, northwestern Canada, as a test case. Geology 20: 181-185.

Derry, L.A., Kaufman, A.J. and Jacobsen, S.B. (1992) Sedimentary cycling and environmental change in the Late Proterozoic: evidence from stable and radiogenic isotopes. Geochimica et Cosmochimica Acta 56: 1317-1329.



Kaufman, A.J., Hayes, J. M., Knoll, A.H. and Germs, G.J.B. (1991) Isotopic compositions of carbonates and organic carbon from Upper Proterozoic successions in Namibia: Stratigraphic variation and the effects of diagenesis and metamorphism. Precambrian Research 49: 301-327.

Kaufman, A.J., Hayes, J.M. and Klein, C. (1991) Primary and diagenetic controls of isotopic compositions of iron-formation carbonates. Geochimica et Cosmochimica Acta 54: 3461-3473.



Beukes, N.J., Klein, C., Kaufman, A.J. and Hayes, J.M. (1990) Carbonate petrography, kerogen distribution, and carbon and oxygen isotope variations in an Early Proterozoic transition from limestone to iron-formation deposition, Transvaal Supergroup, South Africa. Economic Geology 85: 663-690.



Knoll, A.H., Hayes, J.M., Kaufman, A.J., Swett, K. and Lambert, I.B. (1986) Secular variations in carbon isotope ratios from Upper Proterozoic successions of Svalbard and East Greenland. Nature 321: 832-838.

Professor Alan Jay Kaufman 
Department of Geology, University of Maryland
College Park, MD 20742-4211
Office: (301) 405-0395, Fax: (301) 405-3597,