The snowball Earth hypothesis: testing the limits of global change

Terra Nova - Tập 14 Số 3 - Trang 129-155 - 2002
Paul F. Hoffman1, Daniel P. Schrag1
1Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138 USA

Tóm tắt

The gradual discovery that late Neoproterozoic ice sheets extended to sea level near the equator poses a palaeoenvironmental conundrum. Was the Earth's orbital obliquity > 60° (making the tropics colder than the poles) for 4.0 billion years following the lunar‐forming impact, or did climate cool globally for some reason to the point at which runaway ice‐albedo feedback created a `snowball' Earth? The high‐obliquity hypothesis does not account for major features of the Neoproterozoic glacial record such as the abrupt onsets and terminations of discrete glacial events, their close association with large (> 10‰) negative δ13C shifts in seawater proxies, the deposition of strange carbonate layers (`cap carbonates') globally during post‐glacial sea‐level rise, and the return of large sedimentary iron formations, after a 1.1 billion year hiatus, exclusively during glacial events. A snowball event, on the other hand, should begin and end abruptly, particularly at lower latitudes. It should last for millions of years, because outgassing must amass an intense greenhouse in order to overcome the ice albedo. A largely ice‐covered ocean should become anoxic and reduced iron should be widely transported in solution and precipitated as iron formation wherever oxygenic photosynthesis occurred, or upon deglaciation. The intense greenhouse ensures a transient post‐glacial regime of enhanced carbonate and silicate weathering, which should drive a flux of alkalinity that could quantitatively account for the world‐wide occurrence of cap carbonates. The resulting high rates of carbonate sedimentation, coupled with the kinetic isotope effect of transferring the CO2 burden to the ocean, should drive down the δ13C of seawater, as is observed. If cap carbonates are the `smoke' of a snowball Earth, what was the `gun'? In proposing the original Neoproterozoic snowball Earth hypothesis, Joe Kirschvink postulated that an unusual preponderance of land masses in the middle and low latitudes, consistent with palaeomagnetic evidence, set the stage for snowball events by raising the planetary albedo. Others had pointed out that silicate weathering would most likely be enhanced if many continents were in the tropics, resulting in lower atmospheric CO2 and a colder climate. Negative δ13C shifts of 10–20‰ precede glaciation in many regions, giving rise to speculation that the climate was destabilized by a growing dependency on greenhouse methane, stemming ultimately from the same unusual continental distribution. Given the existing palaeomagnetic, geochemical and geological evidence for late Neoproterozoic climatic shocks without parallel in the Phanerozoic, it seems inevitable that the history of life was impacted, perhaps profoundly so.

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Tài liệu tham khảo

Aitken J.D., 1991, The Ice Brook Formation and Post‐Rapitan, Late Proterozoic glaciation, Mackenzie Mountains, Northwest Territories, Geol. Surv. Can. Bull., 404

10.2475/ajs.295.4.428

10.1126/science.213.4504.214

10.1029/2000GL011557

10.2475/ajs.301.3.261

10.1029/JB092iB09p08843

10.1007/BF00441228

Bertrand‐Sarfati J., 1997, Lower Cambrian apatitic stromatolites and phospharenites related to the glacio‐eustatic cratonic rebound (Sahara, Algeria), J. Sed. Res., 67, 957

10.1038/189633a0

10.1038/35011045

10.1038/35036572

10.1130/0091-7613(1998)026<0555:ABYOES>2.3.CO;2

10.1130/0091-7613(2000)28<175:NUZDFT>2.0.CO;2

10.1144/jgs.157.5.909

10.1016/0301-9268(94)90023-X

Budyko M.I. 1966.Polar ice and climate. In:Proceedings of the Symposium on the Arctic Heat Budget and Atmospheric Circulation(J.O.Fletcher ed.) pp. 3–21. The Rand Corp. Santa Monica CA.

10.1111/j.2153-3490.1969.tb00466.x

10.1666/0094-8373(2000)026<0386:BPNGNS>2.0.CO;2

10.1126/science.11538072

Butterfield N.J., 1994, Paleobiology of the Neoproterozoic Svanbergfjellet Formation, Spitsbergen, Fossils Strata, 34, 1, 10.18261/8200376494-1994-01

10.1130/0091-7613(1998)026<0963:DOWFIP>2.3.CO;2

Cahen L., 1963, Glaciations anciennes et dérive des continents, Ann. Soc. Geol. Belg., 86, 19

10.1038/359226a0

10.1038/24839

10.1126/science.288.5466.658

10.2475/ajs.299.7-9.697

10.1038/382127a0

Chumakov N.M., 1989, The paradox of Late Proterozoic glaciations at low latitudes, Episodes, 12, 115, 10.18814/epiiugs/1989/v12i2/015

10.1016/0301-9268(94)00096-A

10.1126/science.284.5417.1087a

10.1016/0301-9268(87)90072-6

10.1130/0016-7606(1974)85<1869:GSAAVT>2.0.CO;2

Colman A.S.andHolland H.D. 2000.The global diagenetic flux of phosphorus from marine sediments to the oceans: redox sensitivity and the control of atmospheric oxygen levels. In:Marine Authigenesis: from Global to Microbial(C. R. Glenn L. Prévôt‐Lucas and J. Lucas eds).Soc. Econ. Paleont. Mineral. Spec. Publ. 66 53–75.

10.1130/0091-7613(2000)28<951:TFDNGE>2.0.CO;2

10.1130/0091-7613(2002)030<0035:NGRIOA>2.0.CO;2

10.1130/0016-7606(2001)113<1121:GIOANC>2.0.CO;2

Corsetti F.A.andKaufman A.J. in press.Stratigraphic investigations of carbon isotope anomalies and Neoproterozoic ice ages in Death Valley California.Geol. Soc. Am. Bull. in press.

10.1038/230111a0

Croll J., 1867, On the excentricity of the earth's orbit, and its physical relations to the glacial epoch, Phil. Mag., 33, 119, 10.1080/14786446708639757

Crowell J.C., 1983, Ice ages recorded on Gondwanan continents, Du Toit Memorial Lecture, 18, Geol. Soc. S. Afr. Trans., 86, 237

Crowell J.C., 1999, Pre‐Mesozoic ice ages: their bearing on understanding the climate system, Mem. Geol. Soc. Am., 192

10.1029/2000GL011836

Crowley T.J.andNorth G.R. 1991.Paleoclimatology. Oxford University Press New York.

10.1139/e96-064

10.1144/0016-764901061

10.1016/0016-7037(92)90064-P

10.1016/0012-821X(84)90073-6

10.1038/359605a0

Deynoux M. 1980.Les Formations Glaciaires Du Précambriens Terminal et de la Fin de l'Ordovicien En Afrique de l'Ouest.Travaux Des Laboratoires Des Sciences de la Terre St. Jérôme Marseille.

10.1016/0031-0182(82)90072-4

10.1016/0031-0182(85)90082-3

10.1111/j.1365-3091.1989.tb02084.x

10.2475/ajs.276.10.1302

10.1130/0016-7606(1974)85<1099:GMFTOO>2.0.CO;2

10.1038/231498a0

Edwards M.B., 1984, Sedimentology of the Upper Proterozoic glacial record, Verstertana Group, Finnmark, North Norway, Nor. Geol. Unders. Bull., 394

Eisbacher G.H., 1981, Sedimentary tectonics and glacial record in the Windermere Supergroup, Mackenzie Mountains, northwestern Canada, Geol. Surv. Can. Pap., 80

10.1016/0012-821X(86)90197-4

Eriksson E., 1968, Air–ocean–icecap interactions in relation to climatic fluctuations and glaciation cycles, Meteor. Monogr., 8, 68

10.2475/ajs.300.5.347

10.1038/386262a0

10.1016/0012-8252(93)90002-O

Fairchild I.J. 1993.Balmy shores and icy wastes: the paradox of carbonates associated with glacial deposits in Neoproterozoic times. In:Sedimentology Review 1(V. P. Wright ed.) pp. 1–16. Blackwell Scientific Publications Oxford.

10.1016/0301-9268(84)90042-1

10.1126/science.289.5480.756

Fedonkin M.A. 1992.Vendian faunas and the early evolution of metazoa. In:Origin and Early Evolution of the Metazoa(J. H. Lipps and P. W. Signor eds) pp. 87–129. Plenum Press New York.

Fedonkin M.A. 1996.The oldest fossil animals in ecological perspective. In:New Perspectives on the History of Life(M. T. Ghiselin and G. Pinna eds).Mem. Calif. Acad. Sci. 20 31–45.

10.1038/42242

10.1046/j.1365-2117.2002.00166.x

10.1126/science.284.5420.1631

German T.N. 1990.Organicheskii mir milliard let nazad (Organic World a Billion Years Ago). Nauka St. Petersburg.

10.1017/S001675680100574X

10.1016/0895-9811(94)90003-5

Grey K. 1998.Ediacarian acritarchs of Australia. PhD Thesis Macquarie University.

10.1016/S0301-9268(98)00068-0

Grotzinger J.P.andJames N.P. 2000.Precambrian carbonates: evolution of understanding. In:Carbonate Sedimentation and Diagenesis in the Evolving Precambrian World(J. P. Grotzinger and N. P. James eds).SEPM Spec. Publ. 67 3–20.

10.2307/3515096

Halverson G.P. Hoffman P.F. Schrag D.P.andKaufman A.J. 2002.A major perturbation of the carbon cycle before the Ghaub glaciation (Neoproterozoic) in Namibia: prelude to snowball Earth?Geochem. Geophys. Geosystems in press.

Halverson G.P.andMaloof A.C. 2001.Getting into global glaciation. J. Conference Abstract. 6 104. Eur. Un. Geosci. Strasbourg.

Hambrey M.J.andHarland W.B. 1981 .Earth's Pre‐Pleistocene Glacial Record. Cambridge University Press Cambridge.

Harland W.B. 1964.Evidence of Late Precambrian glaciation and its significance. In:Problems in Palaeoclimatology(A. E. M. Nairn ed.) pp. 119–149 180–184. Interscience. John Wiley & Sons London.

Harland W.B., 1997, The Geology of Svalbard, Geol. Soc. (London) Mem., 17

10.1038/1841860b0

Harland W.B., 1993, Vendian geology of Svalbard, Norsk Polarinstitut Skrifter, 193

10.1038/scientificamerican0864-28

10.1017/S0016756800066693

Hegenberger W., 1987, Gas escape structures in Precambrian peritidal carbonate rocks, Communs. Geol. Surv. S.W. Africa/Namibia, 3, 49

Hegenberger W., 1993, Stratigraphy and sedimentology of the Late Precambrian Witvlei and Nama Groups, east of Windhoek, Geol. Surv. Namibia Mem., 17

Hoffmann K.‐H., 1996, A preliminary note on a revised subdivision and regional correlation of the Otavi Group based on glaciogenic diamictites and associated cap dolostones, Communs. Geol. Surv. Namibia, 11, 81

10.1130/0091-7613(2002)030<0286:APCCAI>2.0.CO;2

Hoffman P.F., 2001, Theme and variations on Neoproterozoic cap‐carbonate sequences: signatures of snowball Earth events, J. Conf Abstract., Eur. Un. Geosci., 6, 99

Hoffman P.F., 1998, Comings and goings of global glaciations on a Neoproterozoic tropical platform in Namibia, GSA Today, 8, 1

10.1126/science.281.5381.1342

10.1038/17006

Hoffman P.F., 1999, Response: Considering a Neoproterozoic snowball Earth, Science, 284

10.1016/S0899-5362(99)00018-4

10.1038/scientificamerican0100-68

Hoffman P.F. Van Dusen A. Maloof A.C. Ferguson C.andSchrag D.P. 2002b.Glimpse of a terrestrial snowball ocean: sea‐floor dolomite‐barite‐aragonite sequence in a Neoproterozoic cap carbonate northern Canadian Cordillera. Astrobiology Science Conference 2002. Abstract. NASA Ames California in press.

10.1130/0091-7613(1990)018<1199:erfibi>2.3.co;2

Holland H.D. 1984.The Chemical Evolution of the Atmosphere and Oceans. Princeton University Press Princeton NJ.

10.1130/0091-7613(2001)029<0007:OSAEPA>2.0.CO;2

10.1144/GSL.JGS.1908.064.01-04.13

10.2151/jmsj1965.60.1_309

10.1038/35013005

10.1029/1998GL900298

10.1029/1999JB900066

10.1029/95JB01061

10.1016/S0009-2541(99)00080-7

10.1139/e01-046

Jenkins R.J.F. 1992.Functional and ecological aspects of Ediacaran assemblages. In:Origin and Early Evolution of the Metazoa(J. H. Lipps and P. W. Signor eds) pp. 131–176. Plenum Press New York.

10.1029/1999jd901125

10.1029/1999GL900538

10.1016/S0301-9268(01)00161-9

10.1130/0091-7613(1996)024<0867:CIATRO>2.3.CO;2

10.1130/0091-7613(1996)024<0799:WVOMRF>2.3.CO;2

10.1016/0301-9268(91)90039-D

10.1016/0301-9268(94)00070-8

10.1073/pnas.94.13.6600

10.1111/j.1365-3091.1987.tb00590.x

10.2110/jsr.66.1050

10.1130/0091-7613(2001)029<1135:CICONG>2.0.CO;2

10.1130/0091-7613(2001)029<0443:APCCAI>2.0.CO;2

10.1130/0091-7613(1998)026<1059:TOFNG>2.3.CO;2

10.1016/S0012-821X(98)00099-5

Kirschvink J.L. 1992.Late Proterozoic low‐latitude global glaciation: the snowball earth. In:The Proterozoic Biosphere(J. W. Schopf and C. Klein eds) pp. 51–52. Cambridge University Press Cambridge.

10.1073/pnas.97.4.1400

10.2113/gsecongeo.84.7.1733

10.1073/pnas.91.15.6743

10.1016/S0301-9268(99)00067-4

10.1126/science.273.5274.452

10.1126/science.284.5423.2129

10.1038/321832a0

10.1038/356673a0

Köppen W.andWegener A. 1924 .Die Klimate der Geologischen Vorzeit. Gebrüder Borntraeger Berlin.

10.1086/628300

10.1016/0198-0149(85)90017-2

10.1130/0091-7613(1991)019<0299:ICIESO>2.3.CO;2

10.1016/S0009-2541(99)00086-8

Kump L.R.andSeyfried W.E. 2001.Depressurization of hydrothermal vents during snowball Earth: effects on ocean chemistry.Earth System Processes Edinburgh Scotland Progr. Abstracts pp. 110 Geological Society London.

Lachenbruch A.H. 1962.Mechanics of thermal contraction cracks and ice‐wedge polygons in permafrost. Geol. Soc. Am. Spec. Pap. 70.

Lasaga A.C. 1998.Kinetic Theory in the Earth Sciences. Princeton University Press Princeton.

10.1038/361615a0

10.1126/science.1061186

Lemon N.M.andGostin V.A. 1990.Glacigenic sediments of the late Proterozoic Elatina Formation and equivalents Adelaide Geosyncline South Australia. In:The Evolution of a Late Precambrian—Early Paleozoic Rift Complex: the Adelaide Geosyncline(J. B. Jago and P. S. Moore eds).Geol. Soc. Aust. Spec. Publ. 16 149–163.

10.1038/35084192

10.1016/S0301-9268(99)00081-9

10.1038/376053a0

10.1016/S0301-9268(99)00098-4

10.1029/93PA02201

Maloof A.C. Kellogg J.B.andAnders A.M. 2002.On the origin of Neoproterozoic sand wedge polygons.Astrobiology Science ConferenceAbstract NASA Ames CA in press.

10.1029/JD090iD01p02167

10.1029/JD093iD01p00791

Martin H. 1965.The Precambrian geologyof South West Africa and Namaqualand. Precambrian Research Unit. University of Cape Town South Africa.

10.1126/science.288.5467.841

Maugh T.H.1989.Super ice age gave life on Earth growing pains.Los Angeles Times September 7 pp. 1 3 28.

Mawson D., 1949, The late Precambrian ice‐age and glacial record of the Bibliando dome, J. Proc. Roy. Soc. New South Wales, 82, 150, 10.5962/p.360506

Mawson D., 1949, The Elatina glaciation, Trans. R. Soc. S. Aust., 73, 117

10.1029/RG027i004p00471

10.1038/248557a0

McElhinny M.W.andMcFadden P.L. 2000 Paleomagnetism. Academic Press San Diego.

10.1029/2000GL008525

10.1016/S0301-9268(00)00130-3

10.2113/48.3.246

McMillan M.D. 1968.The geology of the Witputs‐Sendelingsdrif area.Bull. Precambr. Res. Unit 4. University of Cape Town.

10.1130/0016-7606(1985)96<1537:GASSTU>2.0.CO;2

10.1016/S0899-5362(97)00073-0

10.1016/S0012-821X(00)00344-7

10.2110/jsr.69.784

10.1017/S0022336000025816

Narbonne G.M., 1990, Ediacaran fossils from the Sekwi Brook area, Mackenzie Mountains, northwestern Canada, Palaeontology, 33, 945

10.1016/0301-9268(94)00073-Z

Néron de Surgy O., 1997, On the long term evolution of the spin of the Earth, Astron. Astrophys., 318, 975

Norin E. 1937.Geology of the western Quruq Tagh eastern Tien Shan. Reports of the Sino‐Swedish Expedition III. Geology. Bokförlags Aktiebolaget Thule Stockholm.

10.1029/RG019i001p00091

Oglesby R.J., 1999, The effect of large fluctuations in obliquity on climates of the late Proterozoic, Paleoclimates, 2, 293

Ojakangas R.W. 1988.Glaciation: an uncommon `mega‐event' as a key to intracontinental and intercontinental correlation of Early Proterozoic basin fill North American and Baltic cratons. In:New Perspectives in Basin Analysis(K. L. Kleinspehn and C. Paola eds) pp. 431–444. Springer New York.

10.1016/S0012-821X(99)00249-6

10.1139/e17-003

10.1029/1999JE001134

10.1080/00167616808728679

10.1111/j.1365-3091.1990.tb00959.x

Peterson K.J., 2001, Fossils, molecular clocks and the Cambrian explosion, Geol. Soc. Am., Abstract. Progr., 33, 430

Plumb K.A. 1981.Late Proterozoic (Adelaidean) tillites of the Kimberley–Victoria River region Western Australia and Northern Territory. In:Earth's Pre‐Pleistocene Glacial Record(M. J. Hambrey and W. B. Harland eds) pp. 504–514. Cambridge University Press Cambridge.

Pollard D., 2001, Coupled GCM‐ice sheet simulations of Sturtian (750–720 Ma) glaciation: When in the snowball‐Earth cycle can tropical glaciation occur?, Eos, 82, S8

10.1666/0094-8373(2000)026<0360:TAITNE>2.0.CO;2

10.1029/2000GL012058

Powell C.McA., 2001, An animated history of Rodinia, Geol. Soc. Aus., Abstract., 65, 85

10.1016/0341-8162(96)00003-3

10.1130/0091-7613(1999)027<0339:TDTCCT>2.3.CO;2

10.1017/S0016756899003155

Preiss W.V., 1987, The Adelaide Geosyncline, S. Aust. Department Mines Energ. Bull., 53

10.1126/science.280.5372.2095

Reusch H., 1891, Skuringsmærker og morængrus eftervist i Finnmarken fra en periode meget ældre end `istiden', Norges Geol. Unders., 1, 78

10.1017/S0016756800004222

10.1086/628173

10.1080/00167618208729222

10.1038/35013168

10.2475/ajs.298.8.621

10.1016/S0031-0182(00)00128-0

10.2110/jsr.68.1223

10.2475/ajs.274.7.673

10.1144/gsjgs.119.1.0201

10.1016/0012-821X(95)00106-M

10.1016/S0012-821X(99)00201-0

10.1016/0012-821X(91)90177-J

Schopf J.W., 1991, Collapse of the Late Proterozoic ecosystem., S. Afr. J. Geol., 94, 33

Schrag D.P. Berner R.A.andHoffman P.F. 2002.On the initiation of a snowball Earth.Geochem. Geophys. Geosystems in press.

10.1038/35053170

10.1144/gsjgs.149.4.0607

10.1175/1520-0450(1969)008<0392:AGCMBO>2.0.CO;2

Sheldon R.P., 1984, Ice‐ring origin of the Earth's atmosphere and hydrosphere and Late Proterozoic–Cambrian phosphogenesis, Geol. Surv. India. Spec. Publ., 17, 17

10.1111/j.1365-3121.1997.tb00016.x

Soffer G. 1998.Evolution of a Neoproterozoic continental margin subject to tropical glaciation.B.A. Thesis Harvard College Cambridge MA.

10.1130/0016-7606(1999)111<1120:PPRIMC>2.3.CO;2

Spencer A.M., 1971, Late Pre‐Cambrian glaciation in Scotland, Mem. Geol. Soc. Lond., 6

10.1144/sjg08030269

Sprigg R.C., 1947, Early Cambrian (?) jellyfishes from the Flinders Ranges, South Australia, Trans. R. Soc. S. Aust., 71, 212

Sprigg R.C. 1952.Sedimentation in the Adelaide geosyncline and the formation of the continental terrace. In:Sir Douglas Mawson Anniversary Volume(M. F. Glaessner and E. A. Rudd eds) pp. 153–159. University of Adelaide Adelaide.

Sprigg R.C. 1990.The Adelaide Geosyncline: a century of controversy. In:The Evolution of a Late Precambrian—Early Paleozoic Rift Complex: the Adelaide Geosyncline(J. B. Jago and P. S. Moore eds).Geol. Soc. Aust. Spec. Publ. 16 66–83.

Summons R.E.andHayes J.M. 1992.Principles of molecular and isotopic biogeochemistry. In:The Proterozoic Biosphere a Multidisciplinary Study(J. W. Schopf and C. Klein eds) pp. 83–93. Cambridge University Press Cambridge.

Sumner D.Y. in press.Rapid calcite and aragonite precipitation in late Archean carbonates and Neoproterozoic cap carbonates. In:Precambrian Sedimentary Environments(W. Altermann ed.).Spec. Publ. Int. Ass. Sed.

10.1130/0091-7613(1996)024<0119:WKOACC>2.3.CO;2

Sumner D.Y., 1987, Soft‐sediment paleomagnetic fold tests of late Precambrian glaciogenic sediments, Eos, 68, 1251

10.1126/science.1063391

10.2475/ajs.300.8.630

10.1016/0012-8252(96)00008-6

10.1016/S0895-9811(98)00036-4

Tsikos H., 1998, The Kalahari manganese field: an enigmatic association of iron and manganese, S. Afr. J. Geol., 101, 287

10.2113/gsecongeo.87.5.1375

10.1029/94PA01455

Van Wagoner J.C. Posamentier H.W. Mitchum R.M. Vail P.R. Sarg J.F. Loutit T.S.andHardenbol J. 1988.An overview of the fundamentals of sequence stratigraphy and key definitions. In:Sea‐Levels Changes—an Integrated Approach(C. K. Wilgus H. Posamenier C. A. Ross and C. G. St. C. Kendall eds).Soc. Econ. Paleont. Mineral. Spec. Publ. 42 39–45.

10.1016/S0009-2541(99)00081-9

10.1016/0016-7037(92)90033-F

10.1038/297057a0

10.1017/S0094837300016808

10.1126/science.287.5462.2421b

10.1080/08120098808729439

Walker J.C.G. 2001.Strange weather on snowball Earth.Earth System Processes Edinburgh Scotland Progr. Abstracts pp. 110–111 Geological Society London.

10.1016/0301-9268(85)90031-2

10.1029/JC086iC10p09776

Walker J.C.G. 2001.Strange weather on snowball Earth.Earth System Processes Edinburgh Scotland Progr. Abstracts pp. 110–111 Geological Society London.

10.1016/0301-9268(83)90008-6

10.1016/S0301-9268(99)00082-0

Wang Y. Lu S. Gao Z. Lin W.andMa G. 1981.Sinian tillites of China. In:Earth's Pre‐Pleistocene Glacial Record(M. J. Hambrey and W. B. Harland eds) pp. 386–401. Cambridge University Press Cambridge.

Warren S.G. Brandt R.E. Grenfell T.C.andMcKay C.P. 2002.Snowball Earth: ice thickness on the tropical ocean.J. Geophys. Res. (Oceans) in press.

Wegener A. 1922.The Origin of Continents and Oceans 3rd edn (J.G.A. Skerl transl.). Methuen London.

10.1175/1520-0469(1975)032<2044:TEOCTS>2.0.CO;2

10.1017/S0016756800046185

10.1080/00167617908729104

10.1016/0012-8252(93)90004-Q

10.1016/S0037-0738(96)00062-0

10.1080/08120099808728429

10.1029/1999rg900016

10.1038/24845

10.1016/S0012-821X(97)00181-7

Williams G.E., 2000, Proterozoic equatorial glaciation: Has `snowball Earth' a snowball's chance?, The Aust. Geologist, 117, 21

10.1080/08120098508729331

10.1130/0091-7613(1991)019<1161:focopa>2.3.co;2

10.1130/0016-7606(1978)89<321:AACSAP>2.0.CO;2

Xiao S., 2001, Neoproterozoic diamictites and stable carbon isotope chemostratigraphy of the Quruqtagh series, NW China, Geol. Soc. Am. Abstract. Progr., 33, A‐144

Yeo G.M. 1981.The late Proterozoic Rapitan glaciation in the northern Cordillera. In:Proterozoic Basins of Canada(F.H.A. Campbell ed.).Geol. Surv. Can. Pap. 81–10.

Yeo G.M. 1986.Iron‐formation in the late Proterozoic Rapitan Group Yukon and Northwest Territories. In:Mineral Deposits of Northern Cordillera(J.A. Morin ed.) Can. Inst. Mining Metallurgy Spec. Vol. 37 142–153.

Young G.M. 1973.Tillites and aluminous quartzites as possible time markers for middle Precambrian (Aphebian) rocks of North America. In:Huronian Stratigraphy and Sedimentation(G. M. Young ed.).Geol. Assoc. Can. Spec. Pap. 12 97–125.

10.1016/0301-9268(76)90030-9

10.1016/0037-0738(88)90066-8

10.1130/0091-7613(1995)023<0153:ANGDPO>2.3.CO;2

Young G.M.andGostin V.A. 1991.Late Proterozoic (Sturtian) succession of the North Flinders basin South Australia: and example of temperate glaciation in an active rift setting. In:Glacial Marine Sedimentation: Paleoclimatic Significance(J. B. Anderson and G. M. Ashley eds).Geol. Soc. Am. Spec. Pap. 261 207–222.

Zhang Y., 1988, Permineralized fossils from the terminal Proterozoic Doushantuo Formation, South China, Paleont. Soc. Mem., 50, 1

10.1029/2000PA000522