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Wabash Formation
The Wabash Formation is a geologic formation in Indiana. It preserves fossils dating back to the Silurian period. See also * List of fossiliferous stratigraphic units in Indiana This article contains a list of fossil-bearing stratigraphic units in the state of Indiana, U.S. Sites See also * Paleontology in Indiana Paleontology in Indiana refers to paleontological research occurring within or conducted by people f ... References Silurian Indiana Silurian southern paleotemperate deposits {{Indiana-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 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] |
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 d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indiana
Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th state on December 11, 1816. It is bordered by Lake Michigan to the northwest, Michigan to the north, Ohio to the east, the Ohio River and Kentucky to the south and southeast, and the Wabash River and Illinois to the west. Various Indigenous peoples of the Americas, indigenous peoples inhabited what would become Indiana for thousands of years, some of whom the U.S. government expelled between 1800 and 1836. Indiana received its name because the state was largely possessed by native tribes even after it was granted statehood. Since then, settlement patterns in Indiana have reflected regional cultural segmentation present in the Eastern United States; the state's northernmost tier was settled primarily by people from New England and New York ... [...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 U.S. state, states, a Washington, D.C., federal district, five major unincorporated territories, nine United States Minor Outlying Islands, Minor Outlying Islands, and 326 Indian reservations. The United States is also in Compact of Free Association, free association with three Oceania, Pacific Island Sovereign state, sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Palau, Republic of Palau. It is the world's List of countries and dependencies by area, third-largest country by both land and total area. It shares land borders Canada–United States border, with Canada to its north and Mexico–United States border, 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 List of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backbone Limestone
The New Harmony Group is located in the State of Indiana. It is made up of three formations, the Grassy Knob Chert, the Backbone Limestone and Clear Creek Chert. It is Lower Devonian in age. Stratigraphy Eastward the group is made up primarily of the Backbone Limestone. It is very light in color, and medium to course grained limestone. The limestone itself is bioclastic. Westward it is very fine grained to medium grained limestone and dolomite with cherty inclusions. To almost pure chert. The cherty facies are the Clear Creek and Grassy Knob formations. There are tongues of chert and limestone that represent facies of each formation interlayed between one another. Clear Creek Chert The Clear Creek Chert is light yellowish grey to olive grey cherty limestone. Grading to predominately chert moving westward. Backbone Limestone The Backbone Limestone is light yellowish grey to yellowish grey. It is fine grained to course grained. There are minor cherty inclusions within the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detroit River Formation
The Detroit River Group is a geologic group in Michigan and Ohio. 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 .... References * Further reading * Brian R. Pratt, ''Lower Devonian Stromatoporoid reefs. Formosa Reef Limestone (Detroit River Group) of Southwestern Ontario.'' In: ''Reefs, Canada and Adjacent Area'', ed. by H.H.J. Geldsetzer, N.P. James and G.E. Tebbutt, Editors Canadian Society of Petroieum Geologists Memoir 13, 1989, p. 506-509 * Gilbert Klapper and, William A. Oliver, Jr., ''The Detroit River Group is Middle Devonian: Discussion on "Early Devonian age of the Detroit River Group, inferred from Arctic stromatoporoids".'' (Canadian Journal of Earth Sciences, 1995, 32(7): 1070–1073, https://doi.org/10 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grassy Knob Chert
The New Harmony Group is located in the State of Indiana. It is made up of three formations, the Grassy Knob Chert, the Backbone Limestone and Clear Creek Chert. It is Lower Devonian in age. Stratigraphy Eastward the group is made up primarily of the Backbone Limestone. It is very light in color, and medium to course grained limestone. The limestone itself is bioclastic. Westward it is very fine grained to medium grained limestone and dolomite with cherty inclusions. To almost pure chert. The cherty facies are the Clear Creek and Grassy Knob formations. There are tongues of chert and limestone that represent facies of each formation interlayed between one another. Clear Creek Chert The Clear Creek Chert is light yellowish grey to olive grey cherty limestone. Grading to predominately chert moving westward. Backbone Limestone The Backbone Limestone is light yellowish grey to yellowish grey. It is fine grained to course grained. There are minor cherty inclusions within the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louisville Limestone
The Louisville Limestone is a geologic formation in Ohio. It preserves fossils dating back to the Silurian period. See also * List of fossiliferous stratigraphic units in Ohio This article contains a list of fossil-bearing stratigraphic units in the state of Ohio, U.S. Sites See also * Paleontology in Ohio References * {{DEFAULTSORT:Fossiliferous stratigraphic units in Ohio Ohio Paleontology in Ohio St ... References * Silurian Ohio Silurian Kentucky Silurian southern paleotemperate deposits Homerian Gorstian Ludfordian {{Ohio-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleasant Mills 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 W ... [...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 ab ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
