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Cherry Canyon Formation
The Cherry Canyon Formation is a geologic formation found in the Delaware Basin of southeastern New Mexico and western Texas. It contains fossils characteristic of the Guadalupian Age of the Permian Period.Kues and Giles 2004, p.100 Description The formation consists mostly of cyclic marine sandstone and siltstone, but with interfingering tongues of gray limestone (the Getaway, South Wells, and Manzanita Members). These extend from the Goat Seep reef, an earlier and much smaller precursor to the Capitan reef, into what was then deep, anoxic water of the Permian Basin. A lower tongue of the formation extends across the basin margin to grade into the nearby San Andres Formation. Maximum thickness of the Cherry Canyon Formation is . The formation rests on the Brushy Canyon Formation, but the lower tongue fills a few deep paleochannels that cut down through the Brushy Canyon and the underlying Cutoff Formation into the Victorio Peak Formation.Kues and Giles 2004, p.124 A hiatus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Formation
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] |
Permian
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the region of Perm in Russia. The Permian witnessed the diversification of the two groups of amniotes, the synapsids and the sauropsids ( reptiles). The world at the time was dominated by the supercontinent Pangaea, which had formed due to the collision of Euramerica and Gondwana during the Carboniferous. Pangaea was surrounded by the superocean Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior. Amniotes, which could better cope with these drier conditions, rose to dominance in place of their am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphate Nodule
Phosphorite, phosphate rock or rock phosphate is a non-detrital sedimentary rock that contains high amounts of phosphate minerals. The phosphate content of phosphorite (or grade of phosphate rock) varies greatly, from 4% to 20% phosphorus pentoxide (P2O5). Marketed phosphate rock is enriched ("beneficiated") to at least 28%, often more than 30% P2O5. This occurs through washing, screening, de-liming, magnetic separation or flotation. By comparison, the average phosphorus content of sedimentary rocks is less than 0.2%.Blatt, Harvey and Robert J. Tracy, ''Petrology'', Freeman, 1996, 2nd ed. pp. 345–349 The phosphate is present as fluorapatite Ca5(PO4)3F typically in cryptocrystalline masses (grain sizes < 1 μm) referred to as -sedimentary apatite deposits of uncertain origin. It is also present as |
Debris Flow
Debris flows are geological phenomena in which water-laden masses of soil and fragmented rock rush down mountainsides, funnel into stream channels, entrain objects in their paths, and form thick, muddy deposits on valley floors. They generally have bulk densities comparable to those of rock avalanches and other types of landslides (roughly 2000 kilograms per cubic meter), but owing to widespread sediment liquefaction caused by high pore-fluid pressures, they can flow almost as fluidly as water. Debris flows descending steep channels commonly attain speeds that surpass 10 m/s (36 km/h), although some large flows can reach speeds that are much greater. Debris flows with volumes ranging up to about 100,000 cubic meters occur frequently in mountainous regions worldwide. The largest prehistoric flows have had volumes exceeding 1 billion cubic meters (i.e., 1 cubic kilometer). As a result of their high sediment concentrations and mobility, debris flows can be very des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hiatus (geology)
An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval of time before deposition of the younger layer, but the term is used to describe any break in the sedimentary geologic record. The significance of angular unconformity (see below) was shown by James Hutton, who found examples of Hutton's Unconformity at Jedburgh in 1787 and at Siccar Point in 1788. The rocks above an unconformity are younger than the rocks beneath (unless the sequence has been overturned). An unconformity represents time during which no sediments were preserved in a region or were subsequently eroded before the next deposition. The local record for that time interval is missing and geologists must use other clues to discover that part of the geologic history of that area. The interval of geologic time not represented ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Victorio Peak Formation
The Victorio Peak Formation is a geologic formation found in the Delaware Basin in Texas and New Mexico. It preserves fossils dating back to the Leonardian Age of the Permian Period.Kues and Giles 2004 Description The formation consists of light gray limestone and dolomite The total thickness over .King 1942 The base of the formation is largely concealed in the subsurface, and the formation is overlain by the Cutoff Shale. The formation grades laterally to the southeast into the Bone Spring Formation, representing the change from shallow shelf carbonate deposition to deep marine carbonate deposition. To the northwest, the Victorio Peak Formation grades into the Yeso Group and the lower part of the San Andres Formation.Kerans ''et al.'' 1993Kues and Giles 2004, p.100 Fossils The formation contains fossil brachiopods, include '' Productus ivesii'',King and King 1929 ''Dichtyoclostus'', and ''Neospirifer'', fusulinids such as ''Parafusilina'', crinoids, corals, and euomphalid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cutoff Formation
The Cutoff Formation is a geologic formation in Texas and New Mexico, US. It preserves fossils dating back to the Permian period. Description The Cutoff Formation consists of feet of thin limestone beds interbedded with dark shale and sandstone. It grades northwards into the San Andres Formation and is likely correlative with the upper part of the Bone Spring Formation within the Delaware Basin. In age, the formation straddles the Cisuralian - Guadalupian boundary. It lies atop the Victorio Peak or Bone Spring Formation and is overlain by the Brushy Canyon Formation or Cherry Canyon Formation. Both these formations fill paleocanyons cut deeply in the Cutoff Formation, in some cases cutting clear through to the underlying Bone Springs or Victorio Peak beds. The formation is interpreted as a deep basin formation deposited on a drowned shelf to basin topography. It contains numerous turbidite sequences. Fossils Limestone beds of the formation contain chonetid brachiopods ('' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleochannel
A palaeochannel, also spelt paleochannel and also known as palaeovalley or palaeoriver, is a geological term describing a remnant of an inactive river or stream channel that has been filled or buried by younger sediment. The sediments that the ancient channel is cut into or buried by can be unconsolidated, semi-consolidated, consolidated or lithified. The word ''palaeochannel'' is formed from the ''palaeo'', meaning "old," and ''channel''. Recognition A palaeochannel is distinct from the overbank deposits of currently-active river channels, including ephemeral water courses that do not regularly flow (such as the Todd River, Central Australia) because the river bed is filled with sedimentary deposits unrelated to the normal bed load of the current drainage pattern. Many palaeochannels are arranged on old drainage patterns, distinct from the current drainage system of a catchment. For example, palaeochannels may relate to a system of rivers and creeks that drained east–west ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Andres Formation, United States
The San Andres Formation is a geologic formation found in New Mexico and Texas. It contains fossils characteristic of the late Leonardian (Kungurian) Age) of the Permian Period. The formation is the most widely exposed Paleozoic formation in the state of New Mexico, cropping out in a zone wide that extends from west Texas to central New Mexico and with additional exposures in the Zuni Mountains and Sangre de Cristo Mountains. It is also prominent in the subsurface in the San Juan Basin and in eastern New Mexico. Description The formation consists mostly of massive marine limestone. The limestone is typically cherty and poorly fossiliferous, but fossils are locally abundant. The total thickness is up to . The formation is transitional with the underlying Glorieta Sandstone or Yeso Group. Where the basal sandstone beds are a minor component compared with marine limestone, these beds are assigned to the Rio Bonito Member of the San Andres Formation and no Glorieta Sandstone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permian Basin (North America)
The Permian Basin is a large sedimentary basin in the southwestern part of the United States. The basin contains the Mid-Continent oil province, Mid-continent oil field province. This sedimentary basin is located in western Texas and southeastern New Mexico. It reaches from just south of Lubbock, Texas, Lubbock, past Midland, Texas, Midland and Odessa, Texas, Odessa, south nearly to the Rio Grande River in southern West Central Texas, and extending westward into the southeastern part of New Mexico. It is so named because it has one of the world's thickest deposits of Rock (geology), rocks from the Permian geologic period. The greater Permian Basin comprises several component basins; of these, the Midland Basin is the largest, Delaware Basin is the second largest, and Marfa, Texas, Marfa Basin is the smallest. The Permian Basin covers more than , [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capitan Formation
The Capitan Formation is a geologic formation found in western Texas and southeastern New Mexico. It is a fossilized reef dating to the Guadalupian Age of the Permian period. The formation underlies El Capitan in Guadalupe Mountains National Park,"Geologic Formations." Gualadupe Mountains National Park and the formation and its associated basin, shelf margin, and backreef formations have been described as "the largest, best-preserved, most accessible, and most intensively studied Paleozoic reef complex in the world."Kues and Giles 2004, p.125 History of investigation The Guadalupe Mountains were first described in the reports of 1849 and 1850 United States military expeditions to the area. George Shumard was the first geologist to study the area, in 1855, and described an "upper white limestone" containing fossils. These included fusulinids and brachiopods, that were identified correctly by his brother, B.F. Shumard, as Permian in age. However, debate on whether the beds were C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goat Seep Formation
The Goat Seep Formation is a geologic formation found in western Texas and southeastern New Mexico. It is a fossilized reef dating to the Guadalupian Age of the Permian period. The formation underlies Bartlett Peak () and nearby areas in Guadalupe Mountains National Park. Description The Goat Seep Formation consists of up to of massive to thickly bedded light grey to white dolomite. The lower part of the formation contains some sandstone beds. It grades below into the Cherry Canyon Formation and is overlain by the Capitan Formation, a younger Permian reef. The Capitan Formation and Goat Seep Formation are quite similar, but are separated by an unconformity marked by ledges of dark limestone. The formation represents a fossil reef, and grades laterally into the shelf limestones of the Grayburg and Queen Formations. It is regarded as a precursor to the Capitan reef. The reef was built mostly by red ('' Solenopora'') and green ( Dasycladaceae) algae and cyanobacteria (''Girvane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
