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Franconia Formation
The Franconia Formation is a Formation (geology), geologic formation in the upper mid-western United States, with outcroppings found in Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Ohio, and Wisconsin. It preserves fossils dating back to the Cambrian Period (geology), period. It was named the Franconia Formation due to the first published documentation of exposures in vicinity of Franconia, Minnesota, Franconia, Minnesota in the 1897 Ph.D. dissertation by Charles P. Berkley at the University of Minnesota titled Geology of the St. Croix Dalles. The Franconian (stage), Franconian Stage (stratigraphy), stratigraphic stage was named after this formation. The formation consists of fine-grained dolomitic sandstone with interbedded shaly zones, becoming more dolomitic towards the east and south of its extent. See also * List of fossiliferous stratigraphic units in Wisconsin * Paleontology in Wisconsin References * USGS National Geologic Map Database Unit Summary for "Franco ... [...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] |
Potosi Dolomite
The Potosi Formation is a geologic formation in Missouri, Illinois and Indiana. It preserves fossils dating back to the Cambrian period. Paleofauna Monoplacophora Monoplacophora , meaning "bearing one plate", is a polyphyletic superclass of molluscs with a cap-like shell inhabiting deep sea environments . Extant representatives were not recognized as such until 1952; previously they were known only from ... * '' Gayneoconus'' : ''G. echolsi'' See also * List of fossiliferous stratigraphic units in Missouri * Paleontology in Missouri References * Cambrian Missouri Dolomite formations Geography of St. Francois County, Missouri Cambrian System of North America Geologic formations of Missouri Cambrian southern paleotropical deposits {{Missouri-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian Geology Of Wisconsin
The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ago (mya) to the beginning of the Ordovician Period mya. Its subdivisions, and its base, are somewhat in flux. The period was established as "Cambrian series" by Adam Sedgwick, who named it after Cambria, the Latin name for 'Cymru' (Wales), where Britain's Cambrian rocks are best exposed. Sedgwick identified the layer as part of his task, along with Roderick Murchison, to subdivide the large "Transition Series", although the two geologists disagreed for a while on the appropriate categorization. The Cambrian is unique in its unusually high proportion of sedimentary deposits, sites of exceptional preservation where "soft" parts of organisms are preserved as well as their more resistant shells. As a result, our understanding of the Cambrian biolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleontology In Wisconsin
Paleontology in Wisconsin refers to paleontological research occurring within or conducted by people from the U.S. state of Wisconsin. The state has fossils from the Precambrian, much of the Paleozoic, and the later part of the Cenozoic. Most of the Paleozoic rocks are marine in origin. Because of the thick blanket of Pleistocene glacial sediment that covers the rock strata in most of the state, Wisconsin’s fossil record is relatively sparse. In spite of this, certain Wisconsin paleontological occurrences provide exceptional insights concerning the history and diversity of life on Earth. Prehistory Precambrian Many metamorphic, igneous and sedimentary rock units are exposed in the north-central part of Wisconsin. Although they are mostly barren of fossils, some of the sedimentary ones contain stromatolites. Cambrian Exposures of Cambrian rock units, many of which are fossiliferous, occur in western and central Wisconsin, especially along the banks of the Mississippi, Saint ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Fossiliferous Stratigraphic Units In Wisconsin
This article contains a list of fossil-bearing stratigraphic units in the state of Wisconsin, U.S. Sites See also * Paleontology in Wisconsin References * {{DEFAULTSORT:Fossiliferous stratigraphic units in Wisconsin Wisconsin Stratigraphic units A stratigraphic unit is a volume of Rock (geology), rock of identifiable origin and relative age range that is defined by the distinctive and dominant, easily mapped and recognizable petrology, petrographic, lithology, lithologic or paleontology, p ... Stratigraphy of Wisconsin Wisconsin geography-related lists United States geology-related lists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stage (stratigraphy)
In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by convention have the same name, and the same boundaries. Rock series are divided into stages, just as geological epochs are divided into ages. Stages can be divided into smaller stratigraphic units called chronozones. (See chart at right for full terminology hierarchy.) Stages may also be divided into substages or indeed grouped as superstages. The term faunal stage is sometimes used, referring to the fact that the same fauna (animals) are found throughout the layer (by definition). Definition Stages are primarily defined by a consistent set of fossils (biostratigraphy) or a consistent magnetic polarity (see paleomagnetism) in the rock. Usually one or more index fossils that are common, found worldwide, easily recognized, and limited to a sing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franconian (stage)
The Franconian is the middle stage of the Upper or Late Cambrian in North America, equivalent to the Chinese Changshanian with a span of nearly 4.5 million years, from about 497 to 492.5 Ma. The name comes from the Franconia Formation, about 100 feet (30 m) of sandstone and green shale exposed near the town of Franconia in eastern Minnesota, north of St Paul. The Franconian is preceded by the Dresbachian and followed by the Trempealeauan The Trempealeauan is the upper or latest stage of the Upper or Late Cambrian in North America, spanning about 4 million years from about 492.5 to 488.3 m.y.a., equivalent to the Fengshanian of China. The name comes from the Trempealeau Formation, ..., respectively the lower and upper stages of the North American Upper Cambrian or Croixan Series. References * Chen Jun-yuan & Teichert C, 1983; Cambrian Cephalopods, Geology Vol 11, pp647–650, Nov 1983 * Flower R.H.1964, The Nautiloid Order Ellesmerocerida (Cephalopoda) Menoir 12, New Mexic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franconia, Minnesota
Franconia is an unincorporated community in Franconia Township, Chisago County, Minnesota, United States. The community is located south of Taylors Falls near the junction of State Highway 95 ( MN 95) and Franconia Trail. The St. Croix River is nearby. Lawrence Creek flows through the community. Nearby places include Shafer, Taylors Falls, Lindstrom, and Scandia. Franconia is home to the Franconia Sculpture Park at the intersection of Highways 8 and 95. Osceola, Wisconsin is also nearby to the south-southeast. History Franconia was platted in 1858, and named after Franconia, New Hampshire Franconia is a town in Grafton County, New Hampshire, United States. The population was 1,083 at the 2020 census. Set in the White Mountains, Franconia is home to the northern half of Franconia Notch State Park. Parts of the White Mountain Nation ..., the native home of a first settler. A post office called Franconia was established in 1866, and remained in operation until it was d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Period (geology)
The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (scientific branch of geology that aims to determine the age of rocks). It is used primarily by Earth scientists (including geologists, paleontologists, geophysicists, geochemists, and paleoclimatologists) to describe the timing and relationships of events in geologic history. The time scale has been developed through the study of rock layers and the observation of their relationships and identifying features such as lithologies, paleomagnetic properties, and fossils. The definition of standardized international units of geologic time is the responsibility of the International Commission on Stratigraphy (ICS), a constituent body of the International Union of Geological Sciences (IUGS), whose primary objective is to precisely define ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossils
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formation (geology)
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 Wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ironton Sandstone
The Ironton Sandstone is a geologic formation 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 exp ... in Indiana. References Generalized Stratigraphic Column of Indiana Bedrock Geology of Indiana {{Indiana-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
