Black shale Devonian

Devonian black shale Mid-Proterozoic black shales ... 

As seen in Figure 6, mean 8 Mo in these ancient sediments is significantly offset from that of modem seawater and from mean 8 Mo of recent euxinic sediments. The offset is in the direction of less fractionation of Mo isotopes in the oceans (closer to the likely 5 MOjj ), as would be expected if removal of Mo to euxinic sediments expanded at the expense of removal to oxic (and suboxic) sediments. The result is consistent with the hypothesis of expanded ocean anoxia, and consequent increase in the areal extent of euxinic depositional settings, during this time. A similar, albeit smaller, offset is seen in repeated measurements of a Devonian black shale sample (USGS SDO-1 Fig. 6). This shift could he interpreted as consistent with somewhat expanded euxinic deposition during this time—an interpretation consistent with other evidence of expanded Paleozoic ocean anoxia in inland hasins. While further work is needed, these initial results are promising. 

Ridgeley Sandstone Lower Devonian Newton Hamilton Fm., Af. Devonian MaroeUus Black Shale, M. Devonian Mahan-tango Fm., M. Devonian Burket Black Shale, U. Devonian... 

Amino Acids. Traces of amino acids were found in the Devonian Newton Hamilton and Marcellus Formations in a previous study (7). In the present work (Table V) small quantities of amino acids were isolated from the Marcellus shale. In both the earlier work and the present study an amino acid that chromatographed as arginine was found. Other amino acids in the Marcellus black shale are histidine( ), methionine, alanine, tyrosine, valine, leucine or isoleucine, and two unknowns, possibly including aminobutyric acid of nonprotein origin in the Newton Hamilton Formation histidine( ). Ammonia was also present in both the Marcellus and the Newton Hamilton. 

Offshore neritic formations in the Paleozoic rock sequence probably include, on faunal and lithologic grounds, the Lower Ordovician Beekmantown dolomites, Middle Ordovician limestones, and Devonian Marcellus and Burket black shales (Table III). The first two are characterized by 0.1-0.4% organic carbons, very low organic nitrogen, and about 20 p.p.m. hydrocarbons but no carbohydrate residues. The Devonian offshore neritic black shales by contrast... 

Werne J. P., Sageman B. B., Lyons T. W., and Hollander D. J. (2002) An intergrated assessment of a type euxinic deposit evidence for multiple controls on black shale deposition in the Middle Devonian Oatka Creek formation. Am. J. Set 302, 110-143. 

Roen J. B. (1984) Geologic framework and hydrocarbon evaluation of Devonian and Mississippian black shales in the Appalachian Basin. AAPG Eastern Seetion meeting. Am. Assoc. Petrol. Geol. Bull. 68, 1927. 

Roen J. B. and Kepferle R. C. (1993) Petroleum geology of the Devonian and Mississippian black shale of eastern North America. US Geol. Surv. Bull. B1909, A1-A8. 

In 1981, the Ontario Geological Survey began a program to assess the resource potential of the Whitby Formation and the other black shales of Ontario. Prior to this study, information on Ontario s black shales has been very sparse due to poor or non-existent exposure and limited subsurface information. Existing data suggested three units were sufficiently organic-rich to warrant further study—the Ordovician Whitby and the Devonian Kettle Point and Marcellus Formation (JL). ... 

The depositional history of Devonian black shales in the Appalachian, Illinois, and Michigan Basins is still a subject of academic argument it is complicated by the fact that organic matter in marine sediments can be preserved in a number of depositional environments which share a common and necessary requirement of little or no oxygen (11). 

The 50 million years of the Devonian Period provided sufficient time for over 11,000 feet of sedimentary rocks to accumulate in the Appalachian Basin this accumulation was controlled by pulses of tectonic uplift to the east. A similar control of a northwestern source area by intermittent tectonic movement is suggested as a source for the upper wedges (B/C) in the Michigan and Illinois Basins. The lower black shales (A) of regional type represent quiescent periods of slow deposition followed by relatively more rapid sedimentation occurring in response to uplift and erosion of source areas and to depositional restrictions caused by rising arches. The total thickness of Devonian shales in either the Michigan or Illinois Basin is less than 1000 feet, so that the sediment volume involved in these two basins is far less than in the Appalachian Basin. Thus there was ample time for... 

Lineback, J. A., "Coordinated Study of the Devonian Black Shale in the Illinois Basin Illinois, Indiana, and Western Kentucky," Final Report for U.S. Dept. Energy, 111. State Geol. Survey, Urbana, 1981. 

Ettensohn, F. R. and Barron, L. S., Depositional Model for the Devonian-Mississippian Black Shale Sequence of North America A Tectonic-Climatic Approach, in Blackburn, W. H., Compiler, "Black Shale Studies in Kentucky," Final Report, Univ. of Kentucky Research Group (Department of Geology and Kentucky Geological Survey), Lexington, 1980. 

Ettensohn, F. R. and Barron, L. S., "Depositional Model for the Devonian-Mississippian Black Shales of North America A... 

In each of the three areas described above, the black-shale sequence differs in overall aspect from each of the other areas when viewed in outcrops. This difference has led to three sets of stratigraphic nomenclature having been applied to the black Devonian-Mississippian shales. The general distribution of the usages of stratigraphic nomenclature are shown in Figure 2. 

Figure 3. General stratigraphic column for the Devonian-Mississippian black shales in eastern Kentucky. ...

Upper Devonian Black Shales of the Eastern United States... 

Figure 3, Solid-state 13 C-NMR spectra of kerogen and coal samples from Upper Devonian black shales (right) and from other locations as indicated (left).

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