Search results
Results from the WOW.Com Content Network
The new thought is that these ocean currents were slowed by blooms of microscopic marine primary producers, which allowed for the settlement of organic-rich sediments at the seafloor, producing many of the economically productive black shale beds that are present today. To this day it remains an intensely researched subject by scholars and ...
Shale is lithified and cleavable. It must have at least 50-percent of its particles measure less than 0.062 mm. This term is confined to argillaceous, or clay-bearing, rock. There are many varieties of shale, including calcareous and organic-rich; however, black shale, or organic-rich shale, deserves further evaluation.
In Illinois the Formation is divided into two members, the lower Elgin Member (mostly dark gray to brown and black shale with dolomite) and the upper Clermont Member (upper gray pure shale) both with type sections in Fayette County, Iowa. However, in Iowa the Scales, Elgin, and Clermont are all members of the Maquoketa Formation (the Maquoketa ...
The Shalë (Albanian definite form: Shala) or Lumi i Shalës is a river flowing inside the Albanian Alps in northern Albania.Its source is near the village of Theth, close to the border with Montenegro in the Alps of Albania National Park.
The Alum Shale Formation (also known as alum schist and alum slate) is a formation of black shale of Miaolingian (Middle Cambrian) to Tremadocian (Lower Ordovician) in age found predominantly in southern Scandinavia. [1] [2] It is shale or clay slate containing pyrite.
The Rhinestreet Shale is a geologic formation in the Appalachian Basin. It dates back to the Devonian period. The Rhinestreet is an organic or Black Shale found on from the approximately the middle of the Appalachian Basin. [1] Near the Middle of Ohio and Kentucky it reaches the surface on the flank of Cincinnati and Findlay Arches. [2]
For example, concretions in sandstones or shales are commonly formed of a carbonate mineral such as calcite; those in limestones are commonly an amorphous or microcrystalline form of silica such as chert, flint, or jasper; while those in black shale may be composed of pyrite. [18]
[1] [2] It is correlated with Swedish alum shale being its younger facial eastward continuation, and both being a part of the Baltoscandic Cambrian-Ordovician black shale, together with black shales in the Oslo region in Norway, Bornholm, Denmark, and Poland. [2] [3] Other known occurrences are in North America, [4] the Malay Peninsula, [5] and ...