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Bass Islands Group
The Bass Islands Formation is a geologic formation in Michigan. It preserves fossils dating back to the Silurian 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 Michigan References * Silurian Michigan Geologic formations of Michigan {{Michigan-geologic-formation-stub ... [...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] |
Silurian
The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the third and shortest period of the Paleozoic Era, and the third of twelve periods of the Phanerozoic Eon. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by a few million years. The base of the Silurian is set at a series of major Ordovician–Silurian extinction events when up to 60% of marine genera were wiped out. One important event in this period was the initial establishment of terrestrial life in what is known as the Silurian-Devonian Terrestrial Revolution: vascular plants emerged from more primitive land plants, dikaryan fungi started expanding and diversifying along with glomeromycotan fungi, and three groups of arthropods ( myriapods, arachnids and hexapods) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michigan
Michigan ( ) is a peninsular U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, Upper Midwestern United States. It shares water and land boundaries with Minnesota to the northwest, Wisconsin to the west, Indiana and Illinois to the southwest, Ohio to the southeast, and the Canadian Provinces and territories of Canada, province of Ontario to the east, northeast and north. With a population of 10.14 million and an area of , Michigan is the List of U.S. states and territories by population, 10th-largest state by population, the List of U.S. states and territories by area, 11th-largest by area, and the largest by total area east of the Mississippi River.''i.e.'', including water that is part of state territory. Georgia (U.S. state), Georgia is the largest state by land area alone east of the Mississippi and Michigan the second-largest. The state capital is Lansing, Michigan, Lansing, while its most populous city is Detroit. The Metro Detroit r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclave of Alaska in the northwest and the archipelago of Hawaii in the Pacific Ocean. The United States asserts sovereignty over five Territories of the United States, major island territories and United States Minor Outlying Islands, various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's List of countries and dependencies by area, third-largest land area and List of countries and dependencies by population, third-largest population, exceeding 340 million. Its three Metropolitan statistical areas by population, largest metropolitan areas are New York metropolitan area, New York, Greater Los Angeles, Los Angel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Put-in-Bay Dolomite
The Put-in-Bay Dolomite is a geologic formation in Michigan and Ohio. It preserves fossils dating back to the Silurian period. The type locality is South Bass Island in western Lake Erie Lake Erie ( ) is the fourth-largest lake by surface area of the five Great Lakes in North America and the eleventh-largest globally. It is the southernmost, shallowest, and smallest by volume of the Great Lakes and also has the shortest avera .... References * Silurian Michigan Dolomite formations of the United States Geologic formations of Michigan Silurian Ohio Geologic formations of Ohio {{Michigan-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tymochtee Dolomite
The Tymochtee Formation is a geologic formation in Ohio. It preserves fossils dating back to the Silurian 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 Ohio References * Silurian Ohio Silurian southern paleotemperate deposits Dolomite formations of the United States Geologic formations of Ohio {{Ohio-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amherstburg Formation
The Amherstburg Formation is a geologic formation in Ontario, Canada and Michigan, United States. It preserves fossils dating back to the Devonian period. See also * List of fossiliferous stratigraphic units in Ontario This is a list of stratigraphic units in Ontario bearing fossils. See also References * {{Lists of fossiliferous stratigraphic units in Canada Geology of Ontario Ontario Ontario is the southernmost Provinces and territories of C ... References * Devonian Ontario Devonian southern paleotemperate deposits Devonian Michigan Geologic formations of Michigan Geologic formations of Ontario Dolomite formations {{Ontario-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columbus Limestone
The Columbus Limestone is a mapped bedrock unit consisting primarily of fossiliferous limestone. It occurs in Ohio, Pennsylvania, and Virginia in the United States, and in Ontario, Canada. Description Depositional environment The depositional environment was most likely shallow marine. Stratigraphy The Columbus conformably overlies the Lucas Dolomite in northeastern Ohio, and unconformably overlies other dolomite elsewhere. It unconformably underlies the Ohio Shale in northwestern Ohio and the Delaware Limestone in eastern Ohio. Its members include: Bellepoint, Marblehead, Tioga Ash Bed, Venice, Delhi, Klondike, and East Liberty. Notable Exposures *The type section is located in Columbus, Ohio. *The glacial grooves on Kelleys Island are cut into the Columbus Limestone. It is also quarried there. *An exposure in Ontario is located at Ingersoll, Ontario. Fossils The Columbus Limestone contains brachiopods, trilobites, bryozoans, mollusks, corals, stromatoporoids and ech ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helderberg Group
The Helderberg Group is a geologic group that outcrops in the States of New York, Pennsylvania, Maryland, New Jersey, and West Virginia. It also is present subsurface in Ohio and the Canadian provinces of Ontario and Nova Scotia. It preserves fossils dating back to the Early Devonian and Late Silurian period. The name was coined by T.A. Conrad (1839) in the ''New York State Geological Survey Annual Report,'' named for the Helderberg Escarpment or Helderberg Mountains. The upper portion of the Helderberg, or the Kalkberg Formation is host to the Bald Hill ash bed, dated to 417.6 million years ago. The Helderberg is composed chiefly of limestone and dolomite. In Maryland and southern Pennsylvania, the Helderberg is divided into three formations. These are the New Creek Limestone, the Corriganville Limestone, and the Mandata Shale. The total thickness is about . The formations weather easily and are poorly exposed except in cuts and quarries. Stratigraphy Manlius Limes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salina Formation
The Salina Group or Salina Formation is a Late Silurian-age, stratigraphic unit of sedimentary rock that is found in Northeastern and Midwestern North America. Named for its Halite beds, the phrase "Salina Group" was first used as a descriptive term by James D. Dana in 1863. The Salina is an extensive formation. It ranges from West Virginia up through Pennsylvania into Ohio and then Michigan in the United States, and from Pennsylvania into New York. It is also found in the Canadian province of Ontario. (See Figure 1.) The thickness of the Salina Group varies greatly within the two basins, ranging from 84 feet in the southwestern corner of Michigan to an estimated 5,000 feet in that state's Gladwin County. This formation is of economic importance for salt mining, oil reservoir creation, gypsum mining, and potential natural gas storage. Research has also been done on the viability of storing radioactive waste in the salt beds of the Salina. Description The Salina Formation i ... [...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 ... [...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''. Though the fossil record is incomplete, numerous studies have demonstrated that there is enough information available to give a good understanding of the pattern of diversification of life on Earth. In addition, the record can predict and fill gaps such as the discovery of '' Tiktaalik'' in the arctic of Canada. Paleontology includes the study of fossils: their age, method of formation, and evolutionary significance. Specimens are sometimes considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years to 4.1 billion years old. Early edition, published online before print. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
