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Trout Valley Formation
The Trout Valley Formation is a geologic formation in Maine. It preserves fossils dating back to the Devonian period. Description Situated in north-central Maine, the Trout Valley Formation is located in a fault-bounded basin. An erosional unconformity separates it from underlying felsites. The formation exists entirely within the confines of Baxter State Park, and collecting of materials without authorization is prohibited. The formation represents an alluvial fan draining an active volcanic source and has a basal cobble conglomerate, consisting only of rounded fragments of the underlying volcanic felsite, known formally as the Traveler Rhyolite. The conglomerate is overlain by sandstone, which contains lenses of gray shale, black shale and fine conglomerate, in a generally fining-upward sequence. The unit's distal portions terminate in tidal mudflats, which have produced a bivalve-dominated fauna that also yielded the first relatively complete Eurypterid found in northern ... [...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 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 Abraham Gottlob W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eurypterid
Eurypterids, often informally called sea scorpions, are a group of extinct arthropods that form the order Eurypterida. The earliest known eurypterids date to the Darriwilian stage of the Ordovician period 467.3 million years ago. The group is likely to have appeared first either during the Early Ordovician or Late Cambrian period. With approximately 250 species, the Eurypterida is the most diverse Paleozoic chelicerate order. Following their appearance during the Ordovician, eurypterids became major components of marine faunas during the Silurian, from which the majority of eurypterid species have been described. The Silurian genus ''Eurypterus'' accounts for more than 90% of all known eurypterid specimens. Though the group continued to diversify during the subsequent Devonian period, the eurypterids were heavily affected by the Late Devonian extinction event. They declined in numbers and diversity until becoming extinct during the Permian–Triassic extinction event (or sometim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleontology In Maine
The location of the state of Maine Paleontology in Maine refers to paleontological research occurring within or conducted by people from the U.S. state of Maine. The fossil record of Maine is very sparse. Maine came into existence during the Ordovician as other ancient land masses accreted onto North America. At the time Maine was covered by a sea inhabited by a menagerie of invertebrates which included graptolites. During the Devonian, geologic uplift raised Maine above sea level. Early land plants flourished in the terrestrial environments. There is a gap in the local rock record spanning the remainder of the Paleozoic, the Mesozoic, and the Tertiary period of the Cenozoic era. During the Ice Age, Maine was varyingly covered by glaciers or seawater. The Devonian Pertica plant, '' Pertica quadrifaria'', is the Maine state fossil. Prehistory Maine came into existence during the Ordovician as other ancient land masses accreted onto North America. At the time, however, Maine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Fossiliferous Stratigraphic Units In Maine
This article contains a list of fossil-bearing stratigraphic units in the state of Maine, Maine, U.S. Sites See also * Paleontology in Maine References * {{DEFAULTSORT:Fossiliferous stratigraphic units in Maine Fossiliferous stratigraphic units of the United States, Maine Paleontology in Maine, Stratigraphic units Stratigraphy of Maine Maine geography-related lists United States geology-related lists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Katahdin Pluton
Mount Katahdin ( ) is the highest mountain in the U.S. state of Maine at . Named Katahdin, which means "Great Mountain", by the Penobscot Native Americans, it is within Northeast Piscataquis, Piscataquis County, and is the centerpiece of Baxter State Park. It is a steep, tall massif formed from a granite intrusion weathered to the surface. The flora and fauna on the mountain are typical of those found in northern New England. Katahdin was known to the Native Americans in the region and was known to Europeans at least since 1689. It has inspired hikes, climbs, journal narratives, paintings, and a piano sonata. The area around the peak was protected by Governor Percival Baxter starting in the 1930s. Katahdin is the northern terminus of the Appalachian Trail and is near a stretch known as the Hundred-Mile Wilderness. In 1967, Mount Katahdin was designated as a National Natural Landmark by the National Park Service. The mountain is commonly called just "Katahdin", though the of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gilboa Fossil Forest
Gilboa Fossil Forest, New York, United States, is a petrified forest and one of the oldest known forests. Located near the Gilboa Dam in Schoharie County, New York, the region is home to tree trunks from the Devonian period. The fossils, some of the only survivors of their type in the world, are believed to have been from one of the first forests on Earth, and was part of the Earth's afforestation. Paleobotanists have been interested in the site since the 1920s when construction work for a water supply project found several large, vertical fossilized stumps. Some of these remain on display at the Gilboa Dam site () and the New York Power Authority Blenheim-Gilboa Visitor's Center in Schoharie County and at the New York State Museum The New York State Museum is a research-backed institution in Albany, New York, United States. It is located on Madison Avenue, attached to the south side of the Empire State Plaza, facing onto the plaza and towards the New York State Capitol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eurypterid
Eurypterids, often informally called sea scorpions, are a group of extinct arthropods that form the order Eurypterida. The earliest known eurypterids date to the Darriwilian stage of the Ordovician period 467.3 million years ago. The group is likely to have appeared first either during the Early Ordovician or Late Cambrian period. With approximately 250 species, the Eurypterida is the most diverse Paleozoic chelicerate order. Following their appearance during the Ordovician, eurypterids became major components of marine faunas during the Silurian, from which the majority of eurypterid species have been described. The Silurian genus ''Eurypterus'' accounts for more than 90% of all known eurypterid specimens. Though the group continued to diversify during the subsequent Devonian period, the eurypterids were heavily affected by the Late Devonian extinction event. They declined in numbers and diversity until becoming extinct during the Permian–Triassic extinction event (or sometim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psilophyton
''Psilophyton'' is a genus of extinct vascular plants. Described in 1859, it was one of the first fossil plants to be found which was of Devonian age (about ). Specimens have been found in northern Maine, USA; Gaspé Bay, Quebec and New Brunswick, Canada; the Czech Republic; and Yunnan, China. Plants lacked leaves or true roots; spore-forming organs or sporangia were borne on the ends of branched clusters. It is significantly more complex than some other plants of comparable age (e.g. ''Rhynia'') and is thought to be part of the group from within which the modern ferns and seed plants evolved. Description Almost all the species of ''Psilophyton'' have been found in rocks of Emsian age (around ). One exception is ''P. krauselii'', from the Czech Republic, which is younger, being from the upper part of the Middle Devonian (around ). ''Psilophyton dawsonii'' is the best-known species. Compressed and mineralized specimens have been found in several locations, particularly i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conglomerate (geology)
Conglomerate () is a clastic sedimentary rock that is composed of a substantial fraction of rounded to subangular gravel-size clasts. A conglomerate typically contains a matrix of finer-grained sediments, such as sand, silt, or clay, which fills the interstices between the clasts. The clasts and matrix are typically cemented by calcium carbonate, iron oxide, silica, or hardened clay. Conglomerates form by the consolidation and lithification of gravel. They can be found in sedimentary rock sequences of all ages but probably make up less than 1 percent by weight of all sedimentary rocks. In terms of origin and depositional mechanisms, they are closely related to sandstones and exhibit many of the same types of sedimentary structures, e.g., tabular and trough cross-bedding and graded bedding.Boggs, S. (2006) ''Principles of Sedimentology and Stratigraphy.'', 2nd ed. Prentice Hall, New York. 662 pp. Friedman, G.M. (2003) ''Classification of sediments and sedimentary rocks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began domina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Shale
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especially quartz and calcite.Blatt, Harvey and Robert J. Tracy (1996) ''Petrology: Igneous, Sedimentary and Metamorphic'', 2nd ed., Freeman, pp. 281–292 Shale is characterized by its tendency to split into thin layers ( laminae) less than one centimeter in thickness. This property is called '' fissility''. Shale is the most common sedimentary rock. The term ''shale'' is sometimes applied more broadly, as essentially a synonym for mudrock, rather than in the more narrow sense of clay-rich fissile mudrock. Texture Shale typically exhibits varying degrees of fissility. Because of the parallel orientation of clay mineral flakes in shale, it breaks into thin layers, often splintery and usually parallel to the otherwise indistinguishable bedding p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traveler Rhyolite
Traveler(s), traveller(s), The Traveler(s), or The Traveller(s) may refer to: People Generic terms *One engaged in travel *Explorer, one who searches for the purpose of discovery of information or resources *Nomad, a member of a community without fixed habitation *Showman, or funfair traveller *Tourist, one who travels for pleasure or business Specific groups * Romani people, or Roma, or Gypsies, and their subgroups in various countries * Indigenous Norwegian Travellers * Irish Travellers Individuals * List of people known as the Traveller * "The Traveller", pen name of Billy Pinnell (died 1977), sports editor of the ''Bristol Evening Post'' from 1932 to 1956 Arts and entertainment Fictional characters * Traveler (Star Trek), The Traveler (''Star Trek'') * The Traveller (James Herbert) * Travellers, in the novel ''Earthworks (novel), Earthworks'' by Brian Aldiss * Travelers, in D.J. MacHale's ''Pendragon: Journal of an Adventure through Time and Space, Pendragon'' novel series ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
