Gray shale

Peter Zubovic. The coal is overlain by a black shale sequence which, in places, contains abundant pyritized marine fossils. Above the black shale there generally is a gray shale sequence. The thickness of the two units varies from place to place. The total thickness ranges from about 3-50 feet. I do not know the mineralogy of the shale. I suspect that there is a relation between the total thickness of the shale and the vanadium content of the coal. Parts of this area are being mapped at present, and in the near future we expect to have the data necessary to show if this suggested relation is valid. 

BEREA SANDSTONE. Light gray siltstones and sandy siltstones with interbedded medium to dark-gray shales, becoming more shaley toward the base. Contact with underlying Bedford chosen at the point where shale/siltstone content is equal. 0-75 thick in study cores. Pyrite blebs and nodules common. 

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

The lower unit of the Ohio Shale which is present in the outcrop area of eastern Kentucky is the Huron Member. Primarily, the Huron consists of black to brownish-black to gray-black, laminated, siliceous, OM-rich shales. Calcareous laminae, cone-incone limestone, dolomitic gray shales, dolomite beds and biotur-bated greenish-gray shales occur as interbeds and laminae in the lower parts of the member. Pyrite occurs as framboids, nodules, and irregular forms. 

Principal stratigraphic units studied are the Flowerpot Shale and the overoverlying Blaine Formation and Dog Creek Shale (Fig. 3). In outcrops the Flowerpot Shale consists mainly of reddish-brown shale with thin layers of greenish-gray shale, gypsum and dolomite gypsum is more abundant to the... 

Glacial drift Modern valley fill Gray shale Sandstone Limestone Black shale Coal... 

Figure 8. Coal seam highly altered hy basaltic sill at Sopris locality. Large conduit-like mass of sill rock in center with natural coke surrounding. Coke arches up and over the conduit-like mass. Seam is underlain by black shale and capped with a thin black shale and a massive light gray sandstone...

Josephine 62-12-24-4 gray brown podzolic Humboldt Co., Calif., U.S.A. sandstone and shale 5.4 alteration of mica... 

FIGURE 1.3 (See color insert) Pictorial example of bedrock core obtained near the experimental site showing the interbedded fractured shale (black) and limestone (white/gray) that dominates the saturated zone. 

Figure 11 Summary of data for the degree of MIF of the sulfur isotopes in sulfides and sulfates. Data from Farquhar et al. (2000) (chemically defined sulfur minerals ( ) sulfides, ( ) total sulfur, and (O) sulfates (O) macroscopic sulfate minerals) with updated ages and from Bekker et al. (2002) (( ) range of values for pyrites in black shales). The gray band at A S 0 represents the mean and 1 SD of recent sulfides and sulfates from Farquhar et al. (2000).

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. 

The schematic black shale sequence also can be applied to the upper New Albany Shale of the Illinois Basin, where a facies relationship of the green-gray Hannibal/Saverton Shales with the Grassy Creek has been described by Lineback (26) ... 

Figure 6. Regional map of the Ellsworth shale zero line, green-gray Ellsworth-type shales to the west and black Antrim-type shales to the east, (Reproduced with permission from Ref 14. Copyright 1982, Institute of Gas Technology.)...

Three-Lick Bed. Unit consists of three greenish-gray bioturbated shales separated by two black shale beds. Pyrite, present as infilling in burrows and calcisiltite bands are found. 19.6-11.6 thick in study cores. 

Studies in Kentucky have shown that soils derived from the same parent rock, a black fissle shale of Devonian age, can differ greatly in their Mo concentrations (Massey and Lowe, 1961). For example, soils from the Colyer series classed as lithosols, which are shallow, with deep broken topography, contain much higher amounts of Mo than do the red-yellow and gray-brown podzolic intergrade soils that have gentle slopes and are moderately well drained. Some soils in the Colyer series, upon liming, produce Mo concentrations in alfalfa that are toxic to livestock (Massey and Lowe, 1961). 

Lower Devonian sandstones are shallow marine and continental, plant-bearing, interbedded with dark gray silts aud shales, range from fine to coarse grained, are sometimes argillaceous or silty and are cemented with quartz cement. They are one of the most widely deposited sandstones in the study area. Porosity ranges from 2 to 24%, and permeability from 10 to 500 mD. Middle and Upper Devonian sandstones are... 

Photograph 7-96 Kiln feed in thin section. Multicolored particles are grains of polycrystalline limestone (calcite). Gray quartz in center. Brown shale particles (also polycrystalline) indicated with arrows. (S A6714)... 

Photograph 7-97 Feed particles in thin section. Gray quartz (upper center), microcrystalline limestone (left center and bottom right), and dark shale (center). 

Blaiklock Glacier Sandstone and shale (red and gray), pebble conglomerate, slightly warped to form a regional anticline Otter and Haskard Highlands, La Grange Nunataks... 

The shale layers, composed of gray mudstone, range in thickness from 1 to 5 m in the lower part of the... 

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