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Geology Of Illinois
The geology of Illinois includes extensive deposits of marine sedimentary rocks from the Palaeozoic, as well as relatively minor contributions from the Mesozoic and Cenozoic. Ice age glaciation left a wealth of glacial topographic features throughout the state. Precambrian Geology Precambrian rocks of Illinois are deeply buried by 2000–13000 feet (610–3960 m) of later sediments. Drilling has revealed these rocks to be primarily Granite, intrusive felsic igneous rocks, though some Rhyolite, extrusive felsic rocks have also been recovered from boreholes. Precambrian rocks of Illinois are highly faulted; tectonic extension and related thermal subsidence have led to the formation of two major sedimentary basins. These basins, termed the Illinois Basin and Michigan Basin, allowed for extensive deposition of sedimentary rock during the Paleozoic, Palaeozoic Era. The Illinois Basin is a northwest–southeast asymmetrical structural basin that is filled with more than 4000 meters of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Simon Sandstone
The Mount Simon Sandstone is an Upper Cambrian sandstone and is found in many states in the Midwest such as Wisconsin, Minnesota, Iowa, Illinois, and Missouri. The Mount Simon formation is the equivalent of the La Motte Sandstone formation in the St. Francois Mountains of Missouri. It was deposited in a nearshore environment, unconformably overlying Precambrian basement, and underlying the Eau Claire Formation in Wisconsin. The Mount Simon sandstone is named after an escarpment of sandstone in Eau Claire, Wisconsin, called Mount Simon by E.O. Ulrich. Geology The Mount Simon sandstone is composed of three main lithofacies. First, the lower Mount Simon is composed of a medium to coarse gained sandstone, which is interpreted to have a diagenesis of a high-energy river system. The middle Mount Simon is a fine to medium grained sandstone with shale beds in it, which is interpreted to be in a high-energy delta. Finally, the upper Mount Simon is a sandstone that is interpreted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachiopod
Brachiopods (), phylum (biology), phylum Brachiopoda, are a phylum of animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection. Two major categories are traditionally recognized, articulate and inarticulate brachiopods. The word "articulate" is used to describe the tooth-and-groove structures of the valve-hinge which is present in the articulate group, and absent from the inarticulate group. This is the leading diagnostic skeletal feature, by which the two main groups can be readily distinguished as fossils. Articulate brachiopods have toothed hinges and simple, vertically oriented opening and closing muscles. Conversely, inarticulate brachiopods have weak, untoothed hinges and a more complex system of vertical and oblique (diagonal) muscles used to keep the two valves aligned. In many brachio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trilobite
Trilobites (; meaning "three-lobed entities") are extinction, extinct marine arthropods that form the class (biology), class Trilobita. One of the earliest groups of arthropods to appear in the fossil record, trilobites were among the most successful of all early animals, existing in oceans for almost 270million years, with over 22,000 species having been described. Because trilobites had wide diversity and an easily fossilized mineralised exoskeleton made of calcite, they left an extensive fossil record. The study of their fossils has facilitated important contributions to biostratigraphy, paleontology, evolution, evolutionary biology, and plate tectonics. Trilobites are placed within the clade Artiopoda, which includes many organisms that are morphologically similar to trilobites, but are largely unmineralised. The relationship of Artiopoda to other arthropods is uncertain. Trilobites evolved into many ecological niches; some moved over the seabed as predators, scavengers, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lee County, Illinois
Lee County is a county located in the U.S. state of Illinois. According to the 2020 census, it has a population of 34,145. Its county seat is Dixon. The Dixon, IL Micropolitan Statistical Area includes all of Lee County. History The area's first non-native settlers were mostly from the six New England states. The early nineteenth century saw a wave of westward movement from New England, due largely to completion of the Erie Canal and the end of the Black Hawk War. The area that included present-day Lee County was delineated as St. Clair County in 1809. In 1823, a large section of northern St. Clair County was partitioned off as Fulton County. In 1825, the northwestern portion of that county was partitioned off as Putnam County. In 1831, the area was further partitioned into Jo Daviess County. A section of that county was partitioned off in 1836 as Ogle County, and in 1839 the bottom half of Ogle County was split off as Lee County. It is largely understood that the count ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ogle County, Illinois
Ogle County is a county in the northern part of the U.S. state of Illinois. According to the 2020 United States census, it had a population of 51,788. Its county seat is Oregon, and its largest city is Rochelle. Ogle County comprises Rochelle, IL Micropolitan Statistical Area, which is also included in the Rockford- Freeport-Rochelle, IL Combined Statistical Area. History Ogle County was formed in 1836 out of Jo Daviess and LaSalle counties, and named in honor of Captain Joseph Ogle, a veteran of the Revolutionary War who settled in Illinois in 1785. Ogle County government was organized in 1837; before that time it remained assigned to Jo Daviess County for legislative, taxation, and judicial matters. In 1839, part of Ogle County was partitioned off to form Lee County. Ogle County was a New England settlement. The founders of Oregon and Rochelle arrived from New England; they were "Yankees", descendants of English Puritans who had settled New England in the 1600s. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jordan Sandstone
The Jordan Sandstone is a geologic formation in Wisconsin. It preserves fossils dating back to the Cambrian period Period may refer to: Common uses * Period (punctuation) * Era, a length or span of time *Menstruation, commonly referred to as a "period" Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (o .... See also * List of fossiliferous stratigraphic units in Wisconsin * Paleontology in Wisconsin References * Cambrian geology of Wisconsin Sandstone formations of the United States {{Wisconsin-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eminence Formation
The Eminence Formation or Eminence Dolomite is a geologic formation in Missouri. It preserves fossils dating back to the Cambrian period. Paleofauna Monoplacophora * '' Biloboconus'' : ''B. frizzelli'' * '' Potosiplina'' : ''P. delorensis'' See also * List of fossiliferous stratigraphic units in Missouri This article contains a list of fossil-bearing stratigraphic units in the state of Missouri, U.S. Sites See also * Paleontology in Missouri References * {{DEFAULTSORT:Fossiliferous stratigraphic units in Missouri Missouri Stratigraph ... * Paleontology in Missouri References * Cambrian Missouri Dolomite formations of the United States Landforms of Shannon County, Missouri Cambrian southern paleotropical deposits Chert formations Geologic formations of Missouri {{ShannonCountyMO-geo-stub ... [...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 * '' Gayneoconus'' : ''G. echolsi'' See also * List of fossiliferous stratigraphic units in Missouri This article contains a list of fossil-bearing stratigraphic units in the state of Missouri, U.S. Sites See also * Paleontology in Missouri References * {{DEFAULTSORT:Fossiliferous stratigraphic units in Missouri Missouri Stratigraph ... * Paleontology in Missouri References * Cambrian Missouri Dolomite formations of the United States St. Francois County, Missouri Cambrian System of North America Cambrian southern paleotropical deposits Cambrian Illinois Geologic formations of Missouri Geologic formations of Illinois Geologic formations of Indiana {{Missouri-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franconia Formation
The Franconia Formation is a 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. It was named the Franconia Formation due to the first published documentation of exposures in vicinity of Franconia Franconia ( ; ; ) is a geographical region of Germany, characterised by its culture and East Franconian dialect (). Franconia is made up of the three (governmental districts) of Lower Franconia, Lower, Middle Franconia, Middle and Upper Franco ..., 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 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 * Lis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galesville Sandstone
The Galesville 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 Sources * External links Generalized Stratigraphic Column of Indiana Bedrock Indiana Geological Survey Cambrian Indiana Sandstone formations of the United States Geologic formations of Indiana {{Indiana-geologic-formation-stub ... [...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 Sources * External links Generalized Stratigraphic Column of Indiana Bedrock Indiana Geological Survey Cambrian Indiana Sandstone formations of the United States Geologic formations of Indiana {{Indiana-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
