The Cenomanian-Turonian Oceanic Anoxic Event, I. Stratigraphy and distribution of organic carbon-rich beds and the marine δ 13 C excursion
Tóm tắt
Marine strata deposited during late Cenomanian and early Turonian time display lithological, faunal, and geochemical characteristics which indicate that significant parts of the world ocean were periodically oxygen deficient. At, or very close to, the Cenomanian-Turonian boundary, between 90.5 and 91.5 million years ago, oxygen deficiencies were particularly marked over a period of less than 1 my. This short-lived episode of oceanic oxygen deficiency has been termed the Cenomanian-Turonian ‘Oceanic Anoxic Event’ (OAE). Marine sediments deposited during this event are, when compared with most of the Phanerozoic record, uncommonly rich in dark-grey to black, pyritic, laminated shales with total organic carbon contents that range from between 1 and 2% to greater than 20% which is largely of marine planktonic origin. The general lack of bioturbation in these beds is taken to indicate an absence of a burrowing fauna due to anoxic conditions. In coeval pelagic and shelf limestone sections the dark shales may be lacking; in such sections the Cenomanian-Turonian boundary is marked by δ 13 C values of up to +4.0‰ or + 5.0‰ in contrast to δ 13 C values of +2.0‰ to +3.0‰ in limestones directly above and below the boundary. The high δ 13 C values are taken to indicate an enrichment of the global ocean in 13 C values as a result of the preferential extraction of 12 C by marine plankton, the organic components of which were not recycled back to the oceanic reservoir during this period of enhanced organic-carbon burial. In many basins benthonic foraminiferal faunas are lacking in strata at or near the Cenomanian-Turonian boundary or consist of depauperate agglutinate faunas whereas diverse planktonic foraminiferal faunas and radiolarian remains are locally abundant. These zones free of benthonic foraminifera have been previously interpreted as the result of bottom-water oxygen deficiencies.
A correlation between high positive δ 13 C values and manganese enrichment in shelf chalks has been pointed out by other workers; data presented here substantiates this correlation.
Sediments that display one or more of the above characteristics have been studied and identified from diverse basinal settings such as Pacific Basin mid-ocean plateaus, North American cratonic interior seaways, European shelf and interior seaways, circum-African embayments and seaways, Tethyan margins and the Caribbean region. The oxygen-deficient water masses are proposed to have taken the form of an expanded and intensified oxygenminimum zone. Palaeobathymetric interpretation of strata from European and African shelf sequences and sections in the US Western Interior Basin show that shallow embayments, flooded by the rapid Cenomanian-Turonian transgression, were particularly favourable to deposition of anoxic sediments as were the neighbouring shelves and cratonic shallow seaways. The distribution of carbonaceous black shales and coeval light-coloured to red shallow-water limestones marked by a δ
13
C ‘spike’ indicates that the upper surface of the widespread, intensified Cenomanian-Turonian oceanic oxygen-minimum zone was 100 to 200 metres below the surface of the sea in most areas; the lower surface was probably between 1.5 and 2.5 km below sea level. The main phase of the Cenomanian-Turonian OAE as exemplified by the Bonarelli Horizon in the Italian Apennines and the Black Band of Yorkshire and Humberside in England lasted less than 1 my. In some basins where coastal geometry and wind direction were effective in inducing strong upwelling conditions, the propensity for the deposition of carbon-rich facies increased and such facies were deposited in some predicted upwelling zones prior to and following the Cenomanian-Turonian OAE. However, the widespread distribution of anoxic sediments deposited synchronously during such a short-lived event indicates that such sediments are not simply the product of coincidental local climatic or basinal water mass characteristics but are the result of a global expansion and intensification of the Cenomanian-Turonian oxygen-minimum zone related to feedback between sea level rise and regional palaeoceanography. The palaeoceanography of the Cenomanian-Turonian OAE is discussed in detail in a companion paper by Arthur
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Tài liệu tham khảo
Arthur M. A., Natland J. H. , Talwani M., Hay W. W., Ryan W. B. F. Carbonaceous sediments in North and South Atlantic: the role of salinity in stable stratification of early Cretaceous basins Deep Drilling Results in the Atlantic Ocean: Continental Margins and Paleoenvironment 1979 3 297 344 Washington, American Geophysical Union, M. Ewing Series
Arthur M. A., Premoli-Silva I. , Schlanger S. O., Cita M. B. Development of wide-spread organic carbon-rich strata in the Mediterranean Tethys Nature and Origin of Cretaceous Carbon-Rich Facies 1982 London Academic Press 7 54
Arthur M. A., Schlanger S. O. Cretaceous ‘oceanic anoxic events’ as causal factors in development of reef-reservoired giant oil fields Bull. Am. Ass. Petrol. Geol. 1979 63 870 885
Arthur M. A. Schlanger S. O. Jenkyns H. C. The Cenomanian-Turonian oceanic anoxic event II. Paleoceanographic controls on organic matter production and preservation 1986 this volume
Axelrod D. I. Role of volcanism in climate and evolution Spec. Pap. Geol. Soc. Am. 1981 185 1 59
Barron E. J., Washington W. M. Numerical climate modeling: An exploration frontier in petroleum source rock prediction Bull. Am. Ass. Petrol. Geol. 1983 67 419
Berger W., von Rad V. , Hays D. E., Pimm A. C. , et al. Cretaceous and Cenozoic sediments from the Atlantic Ocean Initial Reports Deep Sea Drilling Project 1972 14 Washington D.C. U.S. Government Printing Office 784 954
Birkenmayer K. Jurassic and Cretaceous lithostratigraphic units of the Pieniny Klippen Belt, Carpathians, Poland Studia Geol. Pol. 1977 45 1 58
Birkenmayer K., Jednorowska A. Upper Cretaceous stratigraphy in the Pieniny Nappe at Sromowce Nizne, Pieniny Klippen Belt (Carpathians, Poland) Studia Geol. Pol. 1984 83 25 50
Bolli H. Zur stratigraphie der oberen Kreide in den höheren helvetischen decken Eclog. Geol. Helv. 1944 37 217 329
Bosellini A., Loriga C., Busetto C. I bacini cretacei del Trentino Riv. Ital. Paleont. 1978 84 897 946
Burnhill T. J., Ramsay W. V. , Illing L. V., Hobson G. D. Mid-Cretaceous paleontology and stratigraphy, Central North Sea Petroleum Geology of the Continental Shelf of North-West Europe 1981 London Institute of Petroleum 245 254
Burollet P. F. Contribution à l’étude stratigraphique de la Tunisie centrale Ann. Mines Geol., Tunis 1956 18 1 350
Burollet P. F. Géologie et sédimentologie de la Tunisie Exc. 1975 15 Nice, France IX Cong. Int. Sed. 172 pp
Cahen L. Géologie du Congo Belge 1954 S. A., Liege H. Vaillant-Carmanne 547 pp
Cannon W. F., Force E. R. , Shanks W. P. Potential for high-grade shallow marine manganese deposits in North America Cameron Volume on Unconventional Mineral Deposits 1983 New York American Inst. of Mining Metallurgical and Petroleum Engineers Inc. 175 189
Clifford H. J., Rogers G., Musrati H. , Halbouty M. Geology of a stratigraphic giant: Messla field, Libya Giant Oil Fields of the Decade 1968–1978 1980 30 507 524 Mem. Am. Ass. Petrol. Geol.
Cunningham R., Kroopnick P. M. , Poag W., de Graciansky P. C. , et al. Inorganic and isotopic geochemistry of sediments from DSDP Sites 549–551, northern North Atlantic Initial Reports Deep Sea Drilling Project 1985 80 Washington, D.C. U.S. Government Printing Office 1073 1079
Davies T. A., Luyendyk B. P. , et al. Initial Reports of the Deep Sea Drilling Project 1974 26 Washington, D.C. U.S. Government Printing Office 1129 pp
Davis A. E. The Pepper shale Guide to the mid-Cretaceous geology of Central Texas. Baylor Geol. Soc. 1958 67 69
Deegan C. E., Scull B. J. A proposed standard lithostratigraphic nomenclature for the Central and Northern North Sea Rep. Inst. Geol. Sci., No. 77/25 1977 36 pp
Demaison G. J., Moore G. T. Anoxic environments and oil source bed genesis Bull. Am. Ass. Petrol. Geol. 1980 64 1179 1209
DSDP scientific staff Goban Spur Transect is drilled Geotimes 1982 27/5 23 24
DSDP scientific staff Leg 89 drills Cretaceous volcanics Geotimes 1983 28/4 17 20
Dürr St. H. Geologie de Serrañia de Ronda und ihrer sudwestlicher Auslaüfer (Andaulsien) Geol. Romana 1967 6 1 73
Einsele G., Wiedmann J. , Von Rad U., Hinz K., Sarnthein M., Seibold E. Turonian black shales in the Moroccan coastal basins: first upwelling in the Atlantic Ocean? Geology of the Northwest African Margin 1982 New York Springer-Verlag 396 414
Ernst G., Schmid F., Klischies G. , Wiedmann J. Multistratigraphische Untersuchungen in der Oberkreide des Raums Braunschweig-Hannover Aspeckte der Kreide Europas 1979 6 11 46 Int. Union Geol. Sciences, Series A
Finch R. C. Mesozoic stratigraphy of central Honduras Bull. Am. Ass. Petrol. Geol. 1981 65 1320 1333
Fischer A. G., Arthur M. A. Secular variations in the pelagic realm Spec. Publ. Soc. econ. Paleont. Miner. 1977 25 19 50
Flores G. , Blant G. The Cretaceous and Tertiary sedimentary basins on Mozambique and Zululand Basins Sedimentaires du Littoral Africain 1973 Paris Assoc. Serv. Geol. Africains 81 111
Force E. R., Cannon W. F., Koski R. A., Passmore K. T., Doe B. R. Influences of ocean anoxic events on manganese deposition and ophiolitehosted sulphide preservation Paleoclimate and Mineral Deposits 1983 822 26 29 U.S. Geological Survey Circular
Frush M. P., Eicher D. L. Cenomanian and Turonian foraminifera and paleoenvironments in the Big Bend region of Texas and Mexico Spec. Pap. geol. Ass. Canada 1975 13 277 301
Groupe de travail européen des foraminifères planctoniques Atlas de foraminifères planctoniques du Crétacé Moyen (Mer Boréale et Téthys) Cahiers de Micropaleont. 1979 1 30 pp
Harland W. B., Cox A. U., Llewellyn P. G., Pickton C. A. G., Smith A. G., Walters R. A Geologic Time Scale 1982 Cambridge Cambridge University Press 131 pp
Hart M. B. Oceanic anoxic event 2 on-shore and off-shore S.W. England 1985 6 Proc. Ussher Soc. 183 190
Hart M. B., Bigg P. J. , Neale J. W., Brasier M. D. Anoxic events in the chalk seas of north-west Europe Microfossils from Recent and Fossil Seas 1981 The British Micropalaeont. Soc. 177 185
Hernandez-Pacheco F. Los materiales bituminosos de la Serrañia de Ronda (Málaga) Bolet. Soc. Española Nat. Hist. 1936 36 245 275
Hinte J. E. van A Cretaceous time scale Bull. Am. Ass. Petrol. Geol. 1976 60 498 516
Kauffman E. G. Geological and biological overview: western interior Cretaceous basin Mountain Geologist 1977 14 75 99
Kennedy W. J., Wright C. W., Hancock J. M. Groupe Français de Crétacé Ammonite zonation and correlation of the upper-most Cenomanian and Turonian of southern England, Sarthe, and Touraine Colloque sur le Turonien 1981 Paris Mem. Mus. Nat. His. Naturelle 175 183
Larson R. L., Moberly R. , et al. Initial Reports of the Deep Sea Drilling Project 1975 32 Washington, D.C. U.S. Government Printing Office 973 pp
Lawrence S., Coster P. Petroleum potential of offshore Guyana Oil & Gas Jl. 1985 83 Dec. 9th 67 74
Leplat J., Robaszynski F. Une couche á rotalipores dans les “Dièves” (Crétacé supérieur) dans un sondage à Trith (Nord) Ann. Soc. géol. Nord 1971 91 199 202
Letolle R., Pomerol B. Mise en évidence dans les craies du Bassin de Paris d’un accident dans le répartition du δ13C d’âge Cénomanian terminal C.R. Acad. Sc. Paris 1980 291 133 136 Serie D
McNeil D. H., Caldwell W. G. E. Cretaceous rocks and their foraminifera in the Manitoba escarpment Spec. Pap. Geol. Ass. Canada 1981 21 1 439
Michelsen O. Geology of the Danish Central Graben. 1982 8 132 pp Geol. Survey Denmark, Series B
Naidin D. P. , Reyment R. A., Bengtson P. The Russian platform and the Crimea Aspects of Mid-Cretaceous Geology 1981 New York Academic Press 29 68
Nairn A. E. M. , Moullade M., Nairn A. E. M. Northern and eastern Africa The Phanerozoic Geology of the World II: The Mesozoic, A. 1978 New York Elsevier Sci. Pub. Co. 329 370
Nygaard E., Lieberkind K., Fryeman P. , Kaasschieter J. P. H., Reijers T. J. A. Sedimentology and reservoir parameters of the Chalk Group in the Danish Central Graben Petroleum Geology of the Southeastern North Sea and the Adjacent Onshore Areas. Geol. N Mijnbouw 1983 62 177 190
Parrish J. T. Upwelling and petroleum source beds, with reference to Paleozoic Bull. Am. Ass. Petrol. Geol. 1982 66 750 774
Petters S. W., Ekweozor C. M. Petroleum geology of Benue Trough and southeastern Chad Basin, Nigeria Bull. Am. Ass. Petrol. Geol. 1982b 66 1141 1149
Pratt L. Influence of paleoenvironmental factors on preservation of organic matter in Middle Cretaceous Greenhorn Formation, Pueblo, Colorado Bull. Am. Assoc. Petrol. Geol. 1984 68 1146 1159
Pratt L., Threkeld C. N. , Stott D. F., Glass D. J. Stratigraphic significance of 13C/12C ratios in mid-Cretaceous rocks of the Western Interior, USA The Mesozoic of middle North America 1984 9 305 312 Mem. Can. Petrol. Geol.
Renz O. , Reyment R. A., Bengtson P. Venezuela Aspects of Mid-Cretaceous Regional Geology 1981 New York Academic Press 197 220
Reyment R. A. , Reyment R. A., Bengtson P. Colombia Aspects of Mid-Cretaceous Regional Geology 1981 New York Academic Press 175 196
Robaszynski F. Les foraminifères pélagiques des “Dièves” crétacées aux abords du golfe de Mons (Belgique) Ann. Soc. géol. Nord 1971a 91 31 38
Robaszynski F. Les “Dièves” de Mauberge (Nord) et leurs deux Tourtias (Crétacé supérieur) Ann. Soc. géol. Nord 1971b 91 193 197
Salaj J. Contribution a la microstratigraphie du Mesozoique et du Tertiare de Tunisie septentrionale Notes du Service Geol. de Tunisie 1976 42 29 69
Schäfer W. Ecology and Paleoecology of Marine Environments 1972 Edinburgh Oliver and Boyd 538 pp
Schlanger S. O., Cita M. B. Nature and Origin of Cretaceous Carbon-rich Facies 1982 New York Academic Press 229 pp
Schlanger S. O., Jenkyns H. C. Cretaceous oceanic anoxic events: causes and consequences Geol. Mijnbouw 1976 55 179 184
Schmid F. von, Spaeth C. Erster Nachweis von Schwarzschiefern im Unter-Turon Helgolands (Nordsee, NW-Deutschland) N. Jb. Geol. Pälaont. Mh., H. 1980 11 703 706
Scholle P. A., Arthur M. A. Carbon isotope fluctuations in Cretaceous pelagic limestones: potential stratigraphic and petroleum exploration tool Bull. Am. Ass. Petrol. Geol. 1980 64 67 87
Simpson T. , Saskatchewan Marine lithofacies and biofacies of the Colorado Group (middle Albian to Santonian) Spec. Pap. Geol. Ass. Canada 1975 13 553 587
Stamm R., Thein J. , Von Rad U., Hinz K., Sarnthein M., Seibold E. Sedimentation in the Atlas Gulf, III: Turonian carbonates Geology of the Northwest African Margin 1982 New York Springer-Verlag 459 474
Summerhayes C. P. Organic facies of middle Cretaceous black shales in deep North Atlantic Bull. Am. Ass. Petrol. Geol. 1981 65 2364 2380
Thiede J., Dean W. E., Claypool G. E. , Schlanger S. O., Cita M. B. Oxygen deficient paleoenvironments in the mid-Cretaceous tropical and subtropical Pacific Ocean Nature and Origin of Cretaceous Carbon-rich Facies 1982 London Academic Press 79 100
Thurow J., Kuhnt W., Wiedmann J. Zeitlicher and paläogeographisher Rahmen der Pthanit-und Black Shale Sedimentation in Marokko N. Jb. Geol. Paläont. Abh. 1982 165 147 176
Tissot B., Demaison G., Masson P., Delteil J. R., Combaz A. Paleoenvironment and petroleum potential of middle Cretaceous black shales in Atlantic basins Bull. Am. Ass. Petrol. Geol. 1980 64 2051 2063
Valentine P. C. Upper Cretaceous subsurface stratigraphy and structure of coastal Georgia and South Carolina Prof. Pap. U.S. Geol. Surv. 1982 1222 1 33
Wall J. H. Jurassic and Cretaceous foraminiferal biostratigraphy in the eastern Sverdrup Basin, Canadian Arctic Archipelago Bull. Can. Petroleum Geology 1983 31 246 281
Waples D. W., Cunningham R. , Poag W., de Graciansky P. C. , et al. Shipboard organic geochemistry, Leg 80, Deep Sea Drilling Project Initial Reports Deep Sea Drilling Project 1985 80 Washington, D.C. US Government Printing Office 949 968
Wiedmann J., Butt A., Einsele G. , von Rad U., Hinz K., Sarntheim M., Seibold E. Cretaceous stratigraphy, environment and subsidence history at the Moroccan continental margin Geology of the Northwest African Margin 1982 New York Springer-Verlag 366 395
Winterer E. L., Ewing J. I. , et al. Initial Reports of the Deep Sea Drilling Project 1973 17 Washington, D.C. US Government Printing Office 927 pp