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Jackfork Sandstone
The Jackfork Sandstone, also referred to as the Jackfork Group, is a geologic formation associated with the Ouachita Fold and Thrust Belt exposed in western Arkansas and southeastern Oklahoma. It is named for Jackfork Mountain in Pittsburg and Pushmataha counties, Oklahoma. The Jackfork Sandstone is a thin- to massive-bedded, fine- to coarse-grained, brown, tan, or gray quartzitic sandstone with subordinate brown, silty sandstone and dark gray shale. It outcrops from Pulaski County, Arkansas in the east to Atoka County, Oklahoma in the west, a distance of over 200 miles. It is highly weather-resistant, resulting in a continuous chain of prominent ridges, including Rich Mountain, the second highest natural point in the Ouachita Mountains. Paleoflora * '' Aphlebia'' : ''A. parksii'' * '' Archaeocalamites'' : ''A. stanleyensis'' * '' Bothrodendron'' * ''Calamites'' : ''C. inopinatus'' : ''C. menae'' : ''C. miseri'' * ''Lepidodendron'' : ''L. subclypeatum'' * ''Lepidostrobus'' : '' ... [...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] |
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] |
Sigillaria
''Sigillaria'' is a genus of extinct, spore-bearing, arborescent (tree-like) plants. It was a lycopodiophyte, and is related to the lycopsids, or club-mosses, but even more closely to quillworts, as was its associate ''Lepidodendron''. Fossil records This genus is known in the fossil records from as early as the Middle Devonian or the Late Carboniferous period but dwindled to extinction in the Cisuralian, Early Permian period (age range: from 383.7 to 254.0 million years ago). Fossils are found in Great Britain, United States, Canada, China, Korea, Tanzania and Zimbabwe. Species Species within this genus include: *''S.alveolaris'' Brongniart (1828) *''S.barbata'' Weiss (1887) *''S.bicostata'' Weiss (1887) *''S.boblayi'' Brongniart (1828) *''S.brardii'' Brongniart (1828) *''S.cancriformis'' Weiss (1887) *''S.cristata'' Sauveur (1848) *''S.cumulata'' Weiss (1887) *''S.davreuxii'' Brongniart (1828) *''S.densifolia'' Brongniart (1836) *''S.elegans'' Sternberg (1825) *''S.elonga ... [...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] |
