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Stanley Shale
The Stanley Shale, or Stanley Group, is a Mississippian stratigraphic unit in the Ouachita Mountains of Arkansas and Oklahoma. First described in Arkansas in 1892, this unit was not named until 1902 by J.A. Taff in his study of the Ouachita Mountains of Oklahoma. Taff assigned the town of Stanley in Pushmataha County, Oklahoma as the type locality, but did not designate a stratotype. After introduction into Arkansas in 1909 by Albert Homer Purdue, the unit was redefined in 1918, when the formation known as the Fork Mountain Slate was abandoned and partially combined into the Stanley Shale. As of 2017, a reference section for the Stanley Shale has yet to be designated. The Stanley Shale is recognized as a geologic formation with two sub-units in Arkansas, the Hatton Tuff Lentil and the Hot Springs Sandstone Member, however, several others have been proposed. These include the Chickasaw Creek Member, Chickasaw Creek Tuff, Gap Ridge Sandstone Member, Moyers Member, Parker Hill S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formation (stratigraphy)
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness (geology), thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baryte
Baryte, barite or barytes ( or ) is a mineral consisting of barium sulfate ( Ba S O4). Baryte is generally white or colorless, and is the main source of the element barium. The ''baryte group'' consists of baryte, celestine (strontium sulfate), anglesite (lead sulfate), and anhydrite (calcium sulfate). Baryte and celestine form a solid solution (Ba,Sr)SO4. Names and history The radiating form, sometimes referred to as ''Bologna Stone'', attained some notoriety among alchemists for specimens found in the 17th century near Bologna by Vincenzo Casciarolo. These became phosphorescent upon being calcined. Carl Scheele determined that baryte contained a new element in 1774, but could not isolate barium, only barium oxide. Johan Gottlieb Gahn also isolated barium oxide two years later in similar studies. Barium was first isolated by electrolysis of molten barium salts in 1808 by Sir Humphry Davy in England. The American Petroleum Institute specification API 13/ISO 13500, which gove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuropteris
''Neuropteris'' is an extinct seed fern that existed in the Carboniferous period, known only from fossils. Major species include ''Neuropteris loschi''. See also *Coal forest *''Macroneuropteris ''Macroneuropteris'' is a genus of Carboniferous seed plants in the order Medullosales. The genus is best known for the species ''Macroneuropteris scheuchzeri'', a medium-size tree that was common throughout the late Carboniferous Euramerica. Thr ...'' References Pteridospermatophyta Pennsylvanian plants Prehistoric plant genera Carboniferous first appearances Carboniferous extinctions Fossils of Georgia (U.S. state) Paleozoic life of New Brunswick Paleozoic life of Nova Scotia Paleozoic life of Prince Edward Island Prehistoric plants of North America {{Carboniferous-plant-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lepidostrobus
''Lepidodendron'' is an extinct genus of primitive vascular plants belonging to the family Lepidodendraceae, part of a group of Lycopodiopsida known as scale trees or arborescent lycophytes, related to quillworts and lycopsids (club mosses). They were part of the coal forest flora. They sometimes reached heights of , and the trunks were often over in diameter. They thrived during the Carboniferous Period (358.9 to 298.9 million years ago). Sometimes erroneously called "giant club mosses", the genus was actually more closely related to modern quillworts than to modern club mosses. Within the form classification system used within paleobotany, ''Lepidodendron'' is both used for the whole plant as well as specifically the stems and leaves. Etymology The name ''Lepidodendron'' comes from the Greek λεπίς ', scale, and δένδρον ''dendron'', tree. Growth During the early stages of growth, ''Lepidodendron'' grew as single, unbranched trunk, with leaves growing out ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lepidodendron
''Lepidodendron'' is an extinct genus of primitive vascular plants belonging to the family Lepidodendraceae, part of a group of Lycopodiopsida known as scale trees or arborescent lycophytes, related to Isoetes, quillworts and Lycopodiopsida, lycopsids (club mosses). They were part of the coal forest flora. They sometimes reached heights of , and the trunks were often over in diameter. They thrived during the Carboniferous Period (358.9 to 298.9 million years ago). Sometimes erroneously called "giant club mosses", the genus was actually more closely related to modern quillworts than to modern club mosses. Within the form classification system used within paleobotany, ''Lepidodendron'' is both used for the whole plant as well as specifically the stems and leaves. Etymology The name ''Lepidodendron'' comes from the Greek language, Greek wikt:λεπίς, λεπίς ', scale, and wikt:δένδρον, δένδρον ''dendron'', tree. Growth During the early stages of growth, ''L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calamites
''Calamites'' is a genus of extinct arborescent (tree-like) horsetails to which the modern horsetails (genus ''Equisetum'') are closely related. Unlike their herbaceous modern cousins, these plants were medium-sized trees, growing to heights of 30-50 meters (100-160 feet). They were components of the understories of coal swamps of the Carboniferous Period (around ). Taxonomy A number of organ taxa have been identified as part of a united organism, which has inherited the name ''Calamites'' in popular culture. ''Calamites'' correctly refers only to casts of the stem of Carboniferous/Permian sphenophytes, and as such is a form genus of little taxonomic value. There are two forms of casts, which can give mistaken impressions of the organisms. The most common is an internal cast of the hollow (or pith-filled) void in the centre of the trunk. This can cause some confusion: firstly, it must be remembered that a fossil was probably surrounded with 4-5 times its width in (unpres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aphlebia
Aphlebiae are the imperfect or irregular leaf endings commonly found on ferns and fossils of ferns from the Carboniferous Period, but seem to have disappeared by the beginning of the Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceo .... According to the United States Geological Survey in 1983, “The discovery in recent years of Aplebiæ attached to the rachis of many species of ''Pecopteris'' and ''Sphenopteris'', such as ''P. dentata'', ''P. Biotii, P. abbrebiata, and Sphenopteris cremate'' strengthens the view now generally entertained, that most of the species of Aphlebia are stipal abortive pinnæ growing from the bases of primary or secondary rachises” (101). The word itself is derived from the Greek "phleb-", meaning vein, and "a-", meaning without. References Leave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
