Lower black shale

Black shale Lower Illinois River Basin, Illinois, USA 4 samples 12-21 Warner (2001)... 

Fyffe, L.R. PiCKERILL, R.K. 1993. Geochemistry of Upper Cambrian - Lower Ordovician black shale along a northeastern Appalachian transect. Geological Society of America Bulletin, 105, 897-910. 

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

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... 

Moldowan et al (5) investigated a sediment core, spanning a depth range of 5m, of Lower Toarcian shales from W. Germany specifically at a transition zone from a rather oxidized, shallow-marine, marly sediment to an organic matter-rich, black shale. Variations in distributions of isoprenoid hydrocarbons, steranes and monoaromatic steroids were observed and were related to variations in oxidation/reduction conditions during and shortly after sedimentation. 

The H-15D core penetrates the Michigan Formation, Marshall Sandstone, and Coldwater Shale (Fig. 2). The Marshall portion of the core includes a section of medium-coarse sand near its top (23.8 to 35.7 m depth), and a larger section below of interbedded sandstone, siltstone, and shale, including minor sections of black shale. The LP-1 core contains a thicker sand-dominated sequence of Marshall Sandstone (43.3 to KB.6 m depth), and below that, in the lower portion of the core, consists of interbedded sand, silt and clays, that includes the contact with Coldwater Shale (Fig. 2). The cores... 

Applied to the Michigan Basin in east-west cross section, the "lower black" shale (A) represents the Antrim Shale of western Michigan and that part of the eastern Antrim Shale identified by Subunits 1A, IB, 1C and 2. The "green-gray" facies (C) is the Ellsworth Shale, and the "upper black" (B) is represented by all Antrim Shale above Unit 2 and below the base of the Bedford Shale. The uniformity of the lower beds of the Antrim Shale has been noted by several others (20, 23), and a westward source for the Ellsworth has been postulated by several (20, 23-25) Nevertheless, the westward source seems more applicable to those beds above the western Antrim Shale, i.e., above the beds termed "lower black" in this paper. 

A westward or northwestward source for the Ellsworth/upper Antrim, Hannibal-Saverton/upper Grassy Creek, and lower Coldwater/ upper Sunbury is appropriate for the overall geometry of those "upper shale" bodies. It is clear that in the Appalachian Basin great volumes of clastic material came from the east and that some of the black shales in that basin are true distal facies of great influxes of clastic material from the east. Nevertheless, because the authors believe that the hypothetical black shale sequence also applies east of the Cincinnati/Algonquin Arches (in mirror image), some of the black shales in the basin may prove to be more regional in nature and of the "lower shale" (A) type. 

The pulses of increased clastic influx reflect tectonic activity, as has been suggested by Ettensohn and Barron (30, 31), but with the addition of a northwestern landmass to provide material west of the general line of the Algonquin and Cincinnati Arches. These pulses are represented by the upper wedges (B/C). Between pulses, there was widespread deposition of the "lower black" (A) type of shales which, for the lower Antrim and lower Sunbury equivalents, were little influenced by arches. The southwestern source suggested by Ettensohn and Barron for the Appalachian Basin (30) seems very plausible for the "lower black" shales (A) of the Illinois and Michigan Basins as well. 

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... 

OHIO SHALE. Cleveland Member. Black to brownish-black shale in upper part to olive-black to brownish-gray shale in lower part. 

Figure 17. Carbon isotope fractionations as a function of metamorphic grade. (17A) Compilation of measured values of A(Cc-Gr) shows scatter and disequilibrium at greenschist facies and lower temperature conditions. Many amphibohte facies and most granuhte facies samples show a tight clustering of values consistent with isotope equilibration above 600°C. Values in black are from the Adirondacks (from Kitchen and Valley 1995). (17B) Values of 5 C for a Liassic black shale formation (Hoefs and Frey 1976) showing successive approach to equihbiium at maximum T = 500-600°C (from Sharp et al. 1995).

Guo, W. 2013 Characteristics of Lower Paleozoic Black Shale Reservoir in Weixin District of Northern Yunnan Travmce. Advanced Materials Research 616 217-222. 

Uraniferous Alum shales, Billingen-Ranstad, Sweden Quite often the black shales show a clear uranium enrichment, the Lower Palaeozoic shales containing millions of tonnes of uranium with average contents grading from some 10 to almost 100 ppm U. Their extraction cannot be envisaged with present technology for environmental and technical reasons and under present market conditions. 

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