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The earliest Carboniferous rocks sit conformably on top of the youngest Devonian in Illinois; Carboniferous rocks in the state are areally extensive, regionally very well-exposed, and form a large percentage of the state's bedrock. Illinois remained marine for much of the Carboniferous, with limestones making up most of the rock deposited ...
The Black River Group is a geologic group that covers three sedimentary basins in the Eastern and Midwestern United States. These include the Appalachian Basin, Illinois Basin and the Michigan Basin. It dates back to the Late Ordovician period. It is roughly equivalent to the Platteville Group in Illinois. [1]
The geology of the State of New York is made up of ancient Precambrian crystalline basement rock, forming the Adirondack Mountains and the bedrock of much of the state. These rocks experienced numerous deformations during mountain building events and much of the region was flooded by shallow seas depositing thick sequences of sedimentary rock ...
The Lockport Group is a geologic group in the Appalachian Basin and Michigan Basin in the northeastern United States and Canada. This unit makes up the Niagara Escarpment. Its most famous feature is Niagara Falls. The unit outcrops in New York, Ontario, Michigan, Wisconsin, and Illinois. [1]
The Clinton Group (also referred to as the Clinton Formation or the Clinton Shale) is a mapped unit of sedimentary rock found throughout eastern North America. [1] [2] The interval was first defined by the geologist Lardner Vanuxem, who derived the name from the village of Clinton in Oneida County, New York where several well exposed outcrops of these strata can be found.
In the first New York survey, the Marcellus Shale was placed below the Hamilton Group at the base of the Erie division of the New York system, but this taxonomy is obsolete. [ 41 ] In current practice, the Marcellus Shale (abbr. Dm or Dms) is classified as the basal unit of the Hamilton Group (Dh), [ 17 ] lying beneath the Mahantango Formation ...
The name was coined by T.A Conrad, 1839 in the New York State Geological Survey Annual Report. Named for the Helderberg Escarpment or Helderberg Mountains. [1] The upper portion of the Helderberg, or the Kalkberg Formation is host to the Bald Hill ash bed, dated to 417.6 million years ago. [2] The Helderberg is composed chiefly of limestone and ...
The Triassic Stockton Formation is a mapped bedrock unit in Pennsylvania, New Jersey, and New York. It is named after Stockton, New Jersey , where it was first described. It is laterally equivalent to the New Oxford Formation in the Gettysburg Basin of Pennsylvania and Maryland .