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Morrow Group
The Morrow Group was a geologic group in Arkansas that is now abandoned and replaced by the Bloyd Formation and the Hale Formation. It preserves fossils dating back to the Pennsylvanian period. See also * List of fossiliferous stratigraphic units in Arkansas * Paleontology in Arkansas Paleontology in Arkansas refers to paleontological research occurring within or conducted by people from the United States, U.S. state of Arkansas. The fossil Fossil record, record of Arkansas spans from the Ordovician to the Eocene. Nearly all of ... References * References Carboniferous System of North America Geologic groups of Arkansas {{carboniferous-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Group (stratigraphy)
In geology, a group is a lithostratigraphic unit consisting of a series of related formations that have been classified together to form a group. Formations are the fundamental unit of stratigraphy. Groups may sometimes be combined into supergroups. Groups are useful for showing relationships between formations, and they are also useful for small-scale mapping or for studying the stratigraphy of large regions. Geologists exploring a new area have sometimes defined groups when they believe the strata within the groups can be divided into formations during subsequent investigations of the area. It is possible for only some of the strata making up a group to be divided into formations. An example of a group is the Glen Canyon Group, which includes (in ascending order) the Wingate Sandstone, the Moenave Formation, the Kayenta Formation, and the Navajo Sandstone. Each of the formations can be distinguished from its neighbor by its lithology, but all were deposited in the same vast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atoka Formation
Named after Atoka County, Oklahoma, the Atoka Formation is a geologic formation in central and western Arkansas, eastern Oklahoma, central and western Texas, and eastern New Mexico. It is the surface rock of the Boston Mountains and dominates exposures in the Frontal Ouachita Mountains of the Arkansas River Valley. Sedimentology The Atoka Formation is a sequence of marine sandstone, sandstones, siltstone, siltstones, and shale, shales, and may be as thick at 25,000 feet in the Ouachita Mountains. The formation is conformable with the Bloyd_Formation, Bloyd Shale in the Boston Mountains and the Johns Valley Formation in the Ouachita Mountains. Paleofauna Conodonts * ''Cavusgnathus'' : ''C. lauta'' : ''C. sinuata'' * ''Gnathodus'' : ''G. wapanuckensis'' * ''Gondolella'' : ''G. bella'' * ''Hindeodella'' * ''Ligonodina'' : ''L. lexingtonensis'' * ''Ozarkodina'' : ''O. recta'' * ''Polygnathodella'' : ''P. attenuata'' : ''P. ouachitensis'' * ''Streptognathodus'' : ''S. cancellosus'' : ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleontology In Arkansas
Paleontology in Arkansas refers to paleontological research occurring within or conducted by people from the United States, U.S. state of Arkansas. The fossil Fossil record, record of Arkansas spans from the Ordovician to the Eocene. Nearly all of the state's fossils have come from ancient invertebrate life. During the early Paleozoic, much of Arkansas was covered by seawater. This sea would come to be home to creatures including ''Archimedes (bryozoan), Archimedes'', brachiopods, and conodonts. This sea would begin its withdrawal during the Carboniferous, and by the Permian the entire state was dry land. Landform, Terrestrial conditions continued into the Triassic, but during the Jurassic, another sea encroached into the state's southern half. During the Cretaceous the state was still covered by seawater and home to marine invertebrates such as ''Belemnitella''. On land the state was home to long necked sauropod dinosaurs, who left behind footprints and ostrich dinosaurs such as ''A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Fossiliferous Stratigraphic Units In Arkansas
This article contains a list of fossil-bearing stratigraphic units in the state of Arkansas, U.S. Sites See also * Paleontology in Arkansas References * {{DEFAULTSORT:Fossiliferous stratigraphic units in Arkansas Arkansas 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 Arkansas Arkansas geography-related lists United States geology-related lists ... [...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] |
Group (geology)
In geology, a group is a lithostratigraphic unit consisting of a series of related formations that have been classified together to form a group. Formations are the fundamental unit of stratigraphy. Groups may sometimes be combined into supergroups. Groups are useful for showing relationships between formations, and they are also useful for small-scale mapping or for studying the stratigraphy of large regions. Geologists exploring a new area have sometimes defined groups when they believe the strata within the groups can be divided into formations during subsequent investigations of the area. It is possible for only some of the strata making up a group to be divided into formations. An example of a group is the Glen Canyon Group, which includes (in ascending order) the Wingate Sandstone, the Moenave Formation, the Kayenta Formation, and the Navajo Sandstone. Each of the formations can be distinguished from its neighbor by its lithology, but all were deposited in the same vast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pitkin Formation
The Pitkin Formation, or Pitkin Limestone, is a fossiliferous geologic formation in northern Arkansas that dates to the Chesterian Series of the late Mississippian. This formation was first named the "Archimedes Limestone" by David Dale Owen in 1858, but was replaced in 1904. The Pitkin conformably overlies the Fayetteville Shale and unconformably underlies the Pennsylvanian-age Hale Formation. Some workers have considered the top of the Pitkin Formation to be a separate formation called the Imo Formation. However more recently, others have considered it as an informal member of the Pitkin Formation. Paleofauna Early work aimed at creating a comprehensive list for all fossils found in the Pitkin Formation was done by Easton in 1943. Unless otherwise stated, all species below can be found in his 'Fauna of the Pitkin Formation.' Formanifera *'' Archaediscus'' :''A. stilus'' *'' Asteroarchaediscus'' :''A. rugosus'' *'' Earlandia'' *'' Endothyra'' :''E. kleina'' :''E. phrissa'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hale Formation
The Hale Formation is a Formation (geology), geologic formation in northern Arkansas that dates to the Pennsylvanian (geology)#Subdivisions, Morrowan Series of the early Pennsylvanian (geology), Pennsylvanian.Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Archived from the original on 31 July 2014. Retrieved 8 July 2014. The Hale Formation has two named members: the Cane Hill and the Prairie Grove Members. The lower member is the Cane Hill, a primarily sandstone and shale interval that unconformably overlies the Mississippian (geology), Mississippian-age Pitkin Formation. The upper member, the Prairie Grove Member, is predominately limestone and conformably underlies the Bloyd Formation. Nomenclature Named by J. A. Taff in 1905, the Hale Formation was originally called the "Hale sandstone lentil" of the Morrow Formation after Hale Mountain in Washington County, Arkansas, Washington County, Arkansas. In the same year, George I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pennsylvanian (geology)
The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, in the International Commission on Stratigraphy, ICS geologic timescale, the younger of two period (geology), subperiods (or upper of two system (stratigraphy), subsystems) of the Carboniferous Period. It lasted from roughly . As with most other geochronology, geochronologic units, the stratum, rock beds that define the Pennsylvanian are well identified, but the exact date of the start and end are uncertain by a few hundred thousand years. The Pennsylvanian is named after the U.S. state of Pennsylvania, where the coal-productive beds of this age are widespread. The division between Pennsylvanian and Mississippian (geology), Mississippian comes from North American stratigraphy. In North America, where the early Carboniferous beds are primarily marine limestones, the Pennsylvanian was in the past treated as a full-fledged geologic period between the Mississippian and the Permian. In parts of Europe, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bloyd Formation
The Bloyd Formation, or Bloyd Shale, is a geologic formation in Arkansas. It preserves fossils dating back to the Carboniferous period. Stratigraphy The Bloyd Formation conformably overlies the Hale Formation and unconformably underlies the Atoka Formation. Five formal and one informal members are recognized in the Bloyd Formation (in stratigraphic order): *Kessler Limestone Member *Dye Shale Member *Parthenon Sandstone Member (also known as the "middle Bloyd sandstone") *Woolsey Member *Baldwin coal (an informal unit at the top of the Woolsey Member) *Brentwood Limestone Member In the eastern parts of the Ozarks in Arkansas, the Bloyd Formation becomes undifferentiated with the underlying Hale Formation and is called the Witts Springs Formation. Paleontology Brachiopods *'' Anthracospirifer'' :''A. newberryi'' *'' Antiquatonia'' :''A. coloradoensis'' *'' Hustedia'' :''H. brentwoodensis'' *'' Linoproductus'' :''L. nodosus'' *'' Orthotetes'' *'' Rhynchopora'' :''R. magnicos ... [...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] |
