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Trinity Group (geologic Formation)
The Trinity Group is a group (stratigraphy), group (sequence of rock strata) in the Lower Cretaceous lithostratigraphy of Texas, Arkansas, Mississippi, Louisiana and Oklahoma. It is named for the Trinity River (Texas), Trinity River of Texas. A stratigraphic column at the Mount Bonnell Fault location starts with the Lower Cretaceous Trinity Group overlain by the Edwards Group. Upper Cretaceous formation (geology), formations follow, starting with the Del Rio Clay, Buda Limestone, and then the Eagle Ford Group. Formations within the Trinity Group include the Hammett Formation, Cow Creek Formation, Hensel Formation, and Lower and Upper Glen Rose Formation. The Hammett and the lower portion of the Upper Glen Rose act as confining units (or aquitard) for the Middle Trinity Aquifer. The Upper Glen Rose contains the Upper Trinity Aquifer, which appears to have intra-aquifer groundwater flow with the Edwards Aquifer as water levels are at the same elevation. Vertebrate fauna Crocod ... [...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] |
Mississippi
Mississippi () is a state in the Southeastern region of the United States, bordered to the north by Tennessee; to the east by Alabama; to the south by the Gulf of Mexico; to the southwest by Louisiana; and to the northwest by Arkansas. Mississippi's western boundary is largely defined by the Mississippi River. Mississippi is the 32nd largest and 35th-most populous of the 50 U.S. states and has the lowest per-capita income in the United States. Jackson is both the state's capital and largest city. Greater Jackson is the state's most populous metropolitan area, with a population of 591,978 in 2020. On December 10, 1817, Mississippi became the 20th state admitted to the Union. By 1860, Mississippi was the nation's top cotton-producing state and slaves accounted for 55% of the state population. Mississippi declared its secession from the Union on January 9, 1861, and was one of the seven original Confederate States, which constituted the largest slaveholding states in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hensel Formation
The Hensel Formation or Hensel Sand is a Mesozoic geologic formation in Texas. Fossil ornithopod tracks have been reported from the formation.Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517-607. A stratigraphic column at the Mount Bonnell Fault location starts with the Lower Cretaceous Trinity Group overlain by the Edwards Group. Upper Cretaceous formations follow, starting with the Del Rio Clay, Buda Limestone, and then the Eagle Ford Group. Formations within the Trinity Group include the Hammett Formation, Cow Creek Formation, Hensel Formation, and Lower and Upper Glen Rose Formation. The Hammett and the lower portion of the Upper Glen Rose act as confining units (or aquitard) for the Middle Trinity Aquifer. See also * List of dinosaur-bearing rock formations ** List of stratigraphic units with ornithischian tracks *** Ornithopod tracks * List of fossiliferous stratigraphic units in Texas * Paleontology in Texas Paleontology in Texas refers to paleontologic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hammett Formation
The Hammett Shale is a geologic formation in Texas. It preserves fossils dating back to the Cretaceous period. A stratigraphic column at the Mount Bonnell Fault location starts with the Lower Cretaceous Trinity Group overlain by the Edwards Group. Upper Cretaceous formations follow, starting with the Del Rio Clay, Buda Limestone, and then the Eagle Ford Group. Formations within the Trinity Group include the Hammett Formation, Cow Creek Formation, Hensel Formation, and Lower and Upper Glen Rose Formation. The Hammett and the lower portion of the Upper Glen Rose act as confining units (or aquitard) for the Middle Trinity Aquifer. See also * List of fossiliferous stratigraphic units in Texas * Paleontology in Texas Paleontology in Texas refers to paleontological research occurring within or conducted by people from the U.S. state of Texas. Author Marian Murray has remarked that "Texas is as big for fossils as it is for everything else." Some of the most imp ... Referenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eagle Ford Group
The Eagle Ford Group (also called the Eagle Ford Shale) is a Sedimentary rock, sedimentary rock formation deposited during the Cenomanian and Turonian ages of the Late Cretaceous over much of the modern-day state of Texas. The Eagle Ford is predominantly composed of organic matter-rich fossiliferous marine shales and marls with interbedded thin limestones. It derives its name from outcrops on the banks of the West Fork of the Trinity River (Texas), Trinity River near the old community of Eagle Ford,Hill, R. T. (1887) The topography and geology of the Crosstimbers and surrounding regions in North Texas: American Journal of Science, v. 33, no. 196, pp. 291–303. which is now a neighborhood within the city of Dallas, Texas, Dallas. The Eagle Ford outcrop belt trends from the Oklahoma-Texas border southward to San Antonio, westward to the Rio Grande, Big Bend National Park, and the Quitman Mountains of West Texas.Denne, R. A., Breyer, J. A., Callender, A. D., Hinote, R. E., Karimin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buda Limestone
The Buda Limestone is a geological formation in the High Plains and Trans-Pecos regions of West Texas and in southern New Mexico, whose strata date back to the Late Cretaceous. Pterosaur remains are among the fossils that have been recovered from the formation.Barrett, P.M., Butler, R.J., Edwards, N.P., & Milner, A.R. Pterosaur distribution in time and space: an atlas. p61-107. in Flugsaurier: Pterosaur papers in honour of Peter Wellnhofer. 2008. Hone, D.W.E., and Buffetaut, E. (eds). Zitteliana B, 28. 264p/ref> Description The Buda Limestone is a dense white to yellow sparry limestone with numerous calcite veins that weathers to yellowish or pinkish due to its iron content. In far western Texas, the formation overlies the Del Rio Formation and is in turn overlain by the Eagle Ford Group. The total thickness is about . In trans-Pecos Texas, the formation rests on the Grayson Formation and is overlain by the Boquillas Formation. In the Big Bend National Park area, the formation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Del Rio Clay
The Del Rio Clay is a geologic formation in Texas. It preserves fossils dating back to the Cretaceous period. A stratigraphic column at the Mount Bonnell location starts with the Lower Cretaceous Trinity Group overlain by the Edwards Group and the Georgetown Formation. Upper Cretaceous formations follow, starting with the Del Rio Clay, Buda Limestone, and then the Eagle Ford Group. Formations within the Trinity Group include the Hammett Formation, Cow Creek Formation, Hensel Formation, and Lower and Upper Glen Rose Formation. The Upper Cretaceous rock units confine the Edwards Aquifer within the Edwards Group and Georgetown Formation The Georgetown Formation is a geologic formation in Mexico and the United States. It preserves fossils dating back to the Cretaceous period. A stratigraphic column at the Mount Bonnell location starts with the Lower Cretaceous Trinity Group ov .... See also * List of fossiliferous stratigraphic units in Texas * Paleontology in Texas Refe ... [...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] |
Upper Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and Anta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edwards Group
The Edwards Group is a geologic group in Texas. It preserves fossils dating back to the Cretaceous period. A stratigraphic column at the Mount Bonnell Fault location starts with the Lower Cretaceous Trinity Group overlain by the Edwards Group. Upper Cretaceous formations follow, starting with the Del Rio Clay, Buda Limestone, and then the Eagle Ford Group. Formations within the Edwards Group include the Kainer Formation and the Person Formation. The Kainer Formation includes the Dolomitic, Kirschberg, and Grainstone Members. See also * List of fossiliferous stratigraphic units in Texas * Paleontology in Texas * Edwards Aquifer The Edwards Aquifer is one of the most prolific artesian aquifers in the world. Located on the eastern edge of the Edwards Plateau in the U.S. state of Texas, it is the source of drinking water for two million people, and is the primary water su ... References * Cretaceous geology of Texas {{Cretaceous-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Bonnell
Mount Bonnell , also known as Covert Park, is a prominent point alongside the Lake Austin portion of the Colorado River in Austin, Texas. It has been a popular tourist destination since the 1850s. The mount provides a vista for viewing the city of Austin, Lake Austin, and the surrounding hills. It was designated a Recorded Texas Historic Landmark in 1969, bearing Marker number 6473, and was listed on the National Register of Historic Places in 2015. Geography Mount Bonnell is located at 30.3210°N, 97.7736°W (WGS 84 datum). The mount is often described as the highest point in Austin, with the elevation at its peak about 775 feet above mean sea level (AMSL). If Mount Bonnell ever held this distinction, it was only because the city limits did not include the next summit to the north, Mount Barker, which has an elevation of about 840 feet above mean sea level (AMSL) But, City of Austin records indicate the city annexed for "full purpose jurisdiction" both Mt. Bonnell and Mt. Barker ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratigraphic Column
A stratigraphic column is a representation used in geology and its subfield of stratigraphy to describe the vertical location of rock units in a particular area. A typical stratigraphic column shows a sequence of sedimentary rocks, with the oldest rocks on the bottom and the youngest on top. In areas that are more geologically complex, such as those that contain intrusive rocks, faults, and/or metamorphism, stratigraphic columns can still indicate the relative locations of these units with respect to one another. However, in these cases, the stratigraphic column must either be a structural column, in which the units are stacked with respect to how they are observed in the field to have been moved by the faults, or a time column, in which the units are stacked in the order in which they were formed. Stratigraphy is a branch of geology that concerns the order and relative position of geologic strata and their relationship to the geologic time scale. The relative time sequencing req ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
