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Black Shale—Its Deposition and Diagenesis

Published online by Cambridge University Press:  01 July 2024

Harry A. Tourtelot
Harry A. Tourtelot*
Affiliation:
U.S. Geological Survey, Federal Center, Denver, Colorado 80225
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Abstract

Black shale is a dark-colored mudrock containing organic matter that may have generated hydrocarbons in the subsurface or that may yield hydrocarbons by pyrolysis. Many black shale units are enriched in metals severalfold above expected amounts in ordinary shale. Some black shale units have served as host rocks for syngenetic metal deposits.

Black shales have formed throughout the Earth's history and in all parts of the world. This suggests that geologic processes and not geologic settings are the controlling factors in the accumulation of black shale. Geologic processes are those of deposition by which the raw materials of black shale are accumulated and those of diagenesis in response to increasing depth of burial.

Depositional processes involve a range of relationships among such factors as organic productivity, clastic sedimentation rate, and the intensity of oxidation by which organic matter is destroyed. If enough organic material is present to exhaust the oxygen in the environment, black shale results.

Diagenetic processes involve chemical reactions controlled by the nature of the components and by the pressure and temperature regimens that continuing burial imposes. For a thickness of a few meters beneath the surface, sulfate is reduced and sulfide minerals may be deposited. Fermentation reactions in the next several hundred meters result in biogenic methane, followed successively at greater depths by decarboxylation reactions and thermal maturation that form additional hydrocarbons. Suites of newly formed minerals are characteristic for each of the zones of diagenesis.

Резюме

Резюме

Чёрные сланец является темно окрашенной глинистой породой, содержащей органический материал, который мог явиться источником углеводородов в недрах или из которого можно получить углеводороды пиролизом. Во многих видах чёрного сланца содержание металлов в несколько раз превышает их содержание в обыкновенных сланцах. Некоторые виды чёрного сланца служат вмещающими породами для сингенетических отложений металлов.

Чёрные сланцы формировались в течение всей истории земли и во всех частях мира. Это указывает на то, что геологические процессы и не геологические условия являются определяющими факторами при формировании чёрных сланцев. Геологические процессы включают отложение, в результате которого накапливаются первичные осадки чёрного сланца, и диагенез, присходящий в результате увеличивающейся глубины захоронения осадков.

Процессы отложения включают целый диапазон отношений между такими факторами как органическая продуктивность, скорость седиментации, интенсивность окисления, разрушающего органическое вещество. Если присутствует достаточное количество органического вещества, чтобы истощить кислород в среде, образуется чёрный сланец.

Диагнетические процессы включают химические реакции, определяемые природой составных частей и режимами давлений и температур, вызванных продолжающимся захоронением. На глубине в несколько метров под поверхностю земли восстанавливается сульфат и могут отложиться сульфидные минералы. На глубине в несколько сотен метров в результате реакций брожения образуется биогенетический метан, а на больших глубинах в результате реакций декарбоксилирования и температурного метаморфизма образуются дополнительные углеводороды. Комплексы вновь образованных минералов характеризуют каждую зону диагенеза.

Resümee

Resümee

Schwarzschiefer ist ein dunkler Schieferton, der organische Substanz enthält, die durch Überlagerung oder durch Pyrolyse Kohlenwasserstoffe bilden kann. Viele Schwarzschieferschichten zeigen eine Anreicherung an Metallen, sodaß ihre Metallgehalte um einiges höher liegen als die der üblichen Schiefer. Einige Schwarzschieferschichten dienten als Muttergestein für syngenetische Metallablagerungen.

Schwarzschiefer wurden während der ganzen Erdgeschichte und überall auf der Erde gebildet. Daraus folgt, daß geologische Prozesse, nicht geologische Gegebenheiten die ausschlaggebenden Faktoren für die Ablagerung von Schwarzschiefer sind. Diese geologischen Prozesse sind die Ablagerung, durch die das Ausgangsmaterial für den Schwarzschiefer sedimentiert wurde und die Diagenese infolge der zunehmenden Überlagerung.

Ablagerungsprozesse werden durch die Einwirkung mehrerer Faktoren beeinflußt, wie z.B. organische tätigkeit, Absatzgeschwindigkeit klastischer Sedimente, und Intensität der Oxidation, durch die organisches Material zerstört wird. Schwarzschiefer entsteht, wenn genügend organisches Material vorhanden ist, um den Sauerstoff der Umgebung zu verbrauchen.

Diagenetische Prozesse beinhalten chemische Reaktionen, die durch die Art der Komponenten sowie durch die herrschenden Druck- und Temperaturverhältnisse kontrolliert werden, die durch zunehmende Überlagerung entstehen. Denn unter einer Überlagerung von einigen Metern wird Sulfat reduziert, und Sulfidminerale können abgelagert werden. Fermentationsreaktionen in den nächsten hundert Metern führen zur Bildung von biogenem Methan. Ihnen folgen mit zunehmender Tiefe nach und nach Decarboxyli-erungsreaktionen und thermische Alterung, die weitere Kohlenwasserstoffe bilden. Abfolgen von neu gebildeten Mineralen sind charakteristisch für jede der Diagenesezonen.

Résumé

Résumé

L'argile shisteuse noire est une roche argileuse foncée contenant de la matière organique qui peut avoir généré des hydrocarbones dans le sous-sol ou qui peut donner des hydrocarbones par pyrolyse. Beaucoup d'unités d'argile shisteuse noire sont enrichies de quantités de métaux plusieurs fois plus importantes que celles aux quelles on s'attendrait dans l'argile shisteuse ordinaire. Certaines unités d'argile shisteuse noire ont servi de roches hôtes pour des dépôts de métal syngénétique.

Les argiles shisteuses noires ont été formées tout au long de l'histoire terrestre et dans toutes les parties du monde. Ceci suggère que ce sont des procèdes géologiques et non des lieux géologiques qui sont les facteurs controllants dans l'accumulation de l'argile shisteuse noire. Les procédés géologiques sont: la déposition par laquelle les matières premières d'argile shisteuse sont accumulées et la diagénèse répondant à une profondeur d'enterrement croissante.

Les procédés de déposition comprennent une étendue de relations entre des facteurs tels la productivité organique, la vitesse de sédimentation élastique et l'intensité d'oxidation par laquelle la matière organique est détruite. S'il ya assez de matière organique pour épuiser l'oxygène de l'environnement, il en résulte une argile shisteuse noire.

Les procédés diagénétiques comprennent des réactions chimiques contrôlés par la nature des composants et par les régimes de pression et de température imposés par l'enterrement continuel. A une épaisseur de quelques mètres sous la surface, la sulphate est réduite et des minéraux sulphides peuvent être déposés. Les réactions de fermentation dans les prochaines centaines de mètres résultent en de la méthane biogènique, suivie successivement à de plus grandes profondeurs de réactions -de decarboxylation et de maturation thermale qui forment d'avantage d'hydrocarbones. Des suites de minéraux nouvellement formés sont caractéristiques de chacune des zones de diagénèse.

Keywords

Black shaleDepositionDiagenesisOrganic matterSyngenetic ores
Type
Research Article
Information
Clays and Clay Minerals , Volume 27 , Issue 5 , October 1979 , pp. 313 - 321
Copyright
Copyright © 1979, The Clay Minerals Society

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Footnotes

1

Invited paper at 1978 Clay Minerals Conference, Bloomington, Indiana.

References

Anger, G., Nielsen, H., Puchelt, H., and Ricke, W. (1966) Sulfur isotopes in the Rammelsberg ore deposit (Germany): Econ. Geol. 61, 511–536.CrossRefGoogle Scholar
Armands, Gösta (1972) Geochemical studies of uranium, molybdenum and vanadium in a Swedish alum shale: Stockholm Contrib. Geol. 27, 148 pp.Google Scholar
Arnold, C. A. (1969) The fossil-plant record: in Aspects of palynology, Tschudy, R. H. and Scott, R. A., eds., Wiley-Interscience, New York, 127–143.Google Scholar
Berner, R. A. (1964) Stability fields of iron minerals in anaerobic marine sediments: J. Geol. 72, 826–834.CrossRefGoogle Scholar
Boyle, R. W. (1968) Fahlbands, sulfide schists, and ore deposition: Econ. Geol. 63, 835–840.Google Scholar
Breger, I. A. and Brown, Andrew (1962) Kerogen in the Chattanooga Shale: Science 137, 221–224.CrossRefGoogle ScholarPubMed
Brookins, D. G. (1976) Shale as a repository for radioactive waste: the evidence from Oklo: Environ. Geol. 1, 255–259.CrossRefGoogle Scholar
Brown, J. P. (1976) Energy from shale—a little used natural resource: in Natural Gas from Unconventional Sources: Natl. Acad. Sci., Board on Mineral Resources, Comm. on Natural Resources, mtg., Jan. 15, 1976, 86–89.Google Scholar
Claypool, G. E. and Kaplan, I. R. (1974) The origin and distribution of methane in marine sediments: in Natural Gases in Marine Sediments, Kaplan, I. R., ed., Plenum, New York, 99–139.CrossRefGoogle Scholar
Clemens, S. L. [Mark Twain] (1874) [1896] Life on the Mississippi: Harper and Bros., New York, 465 pp.Google Scholar
Conant, L. C. and Swanson, V. E. (1961) Chattanooga Shale and related rocks of central Tennessee and nearby areas: U.S. Geol. Surv. Prof. Pap. 357, 91 pp.Google Scholar
Cox, R. and Curtis, R. (1977) Discovery of the Lady Loretta zinc-lead-silver deposit, northwest Queensland, Australia—a geochemical case history: J. Geochem. Explor. 8, 189–202.CrossRefGoogle Scholar
Curtis, C. D. (1977) Sedimentary geochemistry: environments and processes dominated by involvement of an aqueous phase: Philos. Trans. Roy. Soc. London A 286, 353–372.Google Scholar
Davidson, D. F. and Lakin, H. W. (1961) Metal content of some black shales of the western United States: in Geological Survey Research 1961, Short papers in the geologic and hydrologie sciences: U.S. Geol. Surv. Prof. Pap. 424–C, C329–C331.Google Scholar
Davidson, D. F. and Lakin, H. W. (1962) Metal content of some black shales—Pt. 2: in Geological Survey Research 1962, Short papers in the geologic and hydrologic sciences: U.S. Geol. Surv. Prof. Pap. 450–C, C740.Google Scholar
Dean, W. E., Gardner, J. V., Jansa, L. F., Cepek, Pavel, and Seibold, Eugen (1977) Cyclic sedimentation along the continental margin of northwest Africa: in Initial Reports of Deep Sea Drilling Project 41, Yves Lancelot and Eugen Seibold, eds., U.S. Gov. Printing Office, Washington, 965–989.Google Scholar
Didyk, B. M., Simoneit, B. R. T., Brassell, S. C., and Eglinton, Geoffrey (1978) Organic geochemical indicators of paleoenvironmental conditions of sedimentation: Nature 272, 216–222.CrossRefGoogle Scholar
Ensign, C. O. Jr., White, W. S., Wright, J. C., Patrick, J. L., Leone, R. J., Hathaway, D. J., Tramell, J. W., Fritts, J. J., and Wright, T. L. (1968) Copper deposits in the Nonesuch Shale, White Pine, Michigan: in Ore Deposits of the United States, 1933–1967, Graton-Sales Volume 1, Amer. Inst. Min. Metall. Pet. Eng., New York, 460–488.Google Scholar
Fulton, L. J. P. (1977) Stratigraphy and sedimentology of radioactive Devonian-Mississippian shales of the central Appalachian Basin: Ph.D. thesis, University of Cincinnati, 128 pp.Google Scholar
Gammon, J. B. (1966) Fahlbands in the Proterozoic of southern Norway: Econ. Geol. 61, 174–188.CrossRefGoogle Scholar
Gardner, J. V., Dean, W. E., and Jansa, L. F. (1977) Sediments recovered from the northwest African continental margin, Leg 41, Deep sea drilling project: in Initial Reports of Deep Sea Drilling Project 41, Yves Lancelot and Eugen Seibold, eds., U.S. Gov. Printing Office, Washington, 1121–1134.Google Scholar
Goldhaber, M. B. (1978) Euxinic facies: in The Encyclopedia of Sedimentology: Rhodes Fairbridge and Joanne Burgeois, eds., Dowden, Hutchinson, and Ross, Inc., Stroudsburg, Pennsylvania, 296–300.Google Scholar
Goldhaber, M. B. and Kaplan, I. R. (1974) The sulfur cycle: in The Sea 5—Marine Chemistry, the Sedimentary Cycle, Goldberg, E. D., ed., John Wiley, New York, 569–655.Google Scholar
Gulson, B. L. (1977) Application of lead isotopes and trace elements to mapping black shales around a base metal sulfide deposit: J. Geochem. Explor. 8, 85–103.CrossRefGoogle Scholar
Hallam, Anthony (1977) Anoxic events in the Cretaceous ocean: Nature 268, 15–16.CrossRefGoogle Scholar
Harris, A. G., Harris, L. G., and Epstein, J. B. (1978) Oil and gas data from Paleozoic rocks in the Appalachian Basin: maps for assessing hydrocarbon potential and thermal maturity (conodont color alteration isograds and overburden isopachs): U.S. Geol. Surv. Map I–917–E.Google Scholar
Irwin, Hilary Curtis, C. D., and Coleman, Max (1977) Isotopic evidence for sources of diagenetic carbonates formed during burial of organic-rich sediments: Nature 269, 209–213.CrossRefGoogle Scholar
Jewett, J. M., Emery, P. A., and Hatcher, D. A. (1965) The Pleasanton Group (Upper Pennsylvanian) in Kansas: Kansas Geol. Surv. Bull. 175, pt. 4, 1–11.Google Scholar
Kerr, R. A. (1978) Glomar Explorer: New era in deep-sea drilling: Science 200, 1254–1255.CrossRefGoogle ScholarPubMed
Krauskopf, K. B. (1955) Sedimentary deposits of rare metals: in Economic Geology (50th Anniversary Volume, 1905–1955), Bateman, A. M., ed. Econ. Geol. 411–463.Google Scholar
Krumbein, W. C. (1942) Physical and chemical changes in sediments after deposition: J. Sediment. Petrology 12, 111–117.CrossRefGoogle Scholar
Krumbein, W. C. and Garrels, R. M. (1952) Origin and classification of chemical sediments in terms of pH and oxidation-reduction potentials: J. Geol. 60, 1–33.CrossRefGoogle Scholar
Peltola, Esko (1968) On some geochemical features in the black schists of the Outokumpu area, Finland: Geol. Soc. Finland Bull. 40, 39–50.CrossRefGoogle Scholar
Rice, D. D. (1975) Origin of and conditions for shallow accumulations of natural gas: Wyoming Geol. Assoc., 27th Ann. Field Conf. 1975, Guidebook, 267–271.Google Scholar
Schott, G. L., Overbey, W. K. Jr., Hunt, A. E., and Komar, C. A., eds. (1978) First eastern gas shales symposium, October 17–19, 1977, Morgantown, West Virginia: U.S. Dep. Energy, Morgantown Energy Res. Center, MERC/SP–77/5, 783 pp.Google Scholar
Swanson, V. E. (1961) Geology and geochemistry of uranium in marine black shales—a review: U.S. Geol. Surv. Prof. Pap. 356–C, 67–112.Google Scholar
Tourtelot, E. B. (1970) Selected annotated bibliography of minor-element content of marine black shales and related sedimentary rocks, 1930–65: U.S. Geol. Surv. Bull. 1293, 118 pp.Google Scholar
Tourtelot, E. B. and Vine, J. D. (1976) Copper deposits in sedimentary and volcanogenic rocks: U.S. Geol. Surv. Prof. Pap. 907–C, 34 pp.Google Scholar
Tourtelot, H. A. (1964) Minor-element composition and organic carbon content of marine and nonmarine shales of Late Cretaceous age in the western interior of the United States: Geochim. Cosmochim. Acta 28, 1579–1604.CrossRefGoogle Scholar
U.S. Dept. Energy (1977) National gas survey: Supply-technical Advisory Task Force on Non-conventional Natural Gas Resources, J. W. Harbaugh, Chairman, Federal Energy Regulatory Commission (DOE/FERC-0010, UC-13), 108 pp.Google Scholar
Vine, J. D. (1966) Element distribution in some shelf and geosynclinal black shales: U.S. Geol. Surv. Bull. 1214E, 31 pp.Google Scholar
Vine, J. D. and Tourtelot, E. B. (1970) Geochemistry of black shale deposits—a summary report: Econ. Geol. 65, 253–272.CrossRefGoogle Scholar
Wedepohl, K. H., Delevaux, M. H., and Doe, B. R. (1978) The potential source of lead in the Permian Kupferschiefer bed of Europe and some selected Paleozoic mineral deposits in the Federal Republic of Germany: Contrib. Mineral. Petrol. 65, 273–281.CrossRefGoogle Scholar
White, S. M. (1979) Deep-sea drilling: Geotimes 24, 21–23.Google Scholar
Woodring, W. P. (1954) Conference on biochemistry, paleoecology, and evolution: Natl. Acad. Sci. 40, 219–224.CrossRefGoogle ScholarPubMed
Zangerl, Rainer and Richardson, E. S. (1963) The paleoecological history of two Pennsylvanian black shales: Fieldiana, Geol. Mem. 4, 352 pp.Google Scholar