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Bass Islands Formation
The Bass Islands Formation is a geologic formation in Michigan. It preserves fossils dating back to the Silurian period. See also * List of fossiliferous stratigraphic units in Michigan This article contains a list of fossil-bearing stratigraphic units in the state of Michigan, U.S. Sites See also * Paleontology in Michigan References * {{DEFAULTSORT:Fossiliferous stratigraphic units in Michigan Michigan Stratigraphi ... References * Silurian 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 24.6 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 shortest period of the Paleozoic Era. 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) became fully terrestrialized. A significant evolutionary milestone during ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michigan
Michigan () is a state in the Great Lakes region of the upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the 10th-largest state by population, the 11th-largest by area, and the largest by area east of the Mississippi River.''i.e.'', including water that is part of state territory. Georgia is the largest state by land area alone east of the Mississippi and Michigan the second-largest. Its capital is Lansing, and its largest city is Detroit. Metro Detroit is among the nation's most populous and largest metropolitan economies. Its name derives from a gallicized variant of the original Ojibwe word (), meaning "large water" or "large lake". Michigan consists of two peninsulas. The Lower Peninsula resembles the shape of a mitten, and comprises a majority of the state's land area. The Upper Peninsula (often called "the U.P.") is separated from the Lower Peninsula by the Straits of Mackinac, a channel that joins Lak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...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 The Silurian ( ) is a geologic period and system spanning 24.6 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 shortest period of the Paleozo ... period. The type locality is South Bass Island in western Lake Erie. References * Silurian Michigan {{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 The Silurian ( ) is a geologic period and system spanning 24.6 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 shortest period of the Paleozo ... period. See also * List of fossiliferous stratigraphic units in Ohio References * Silurian Ohio Silurian southern paleotemperate deposits {{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 Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept .... See also * List of fossiliferous stratigraphic units in Ontario References * Devonian Ontario Devonian southern paleotemperate deposits Devonian Michigan {{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, and 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 echi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helderberg Group
The Helderberg Group is a geologic group in New York. It preserves fossils dating back to the Devonian period. See also * List of fossiliferous stratigraphic units in New York This article contains a list of fossil-bearing stratigraphic units in the state of New York, U.S. Sites See also * Paleontology in New York References * {{DEFAULTSORT:Fossiliferous stratigraphic units in New York New York Stratigrap ... References * Geologic groups of New York (state) {{NewYork-geologic-formation-stub ... [...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, 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 (state), New York. It is also found in the Provinces and territories of Canada, 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, Michigan, 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 st ... [...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] |
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] |
