|
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] |
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] |
Dolomite (rock)
Dolomite (also known as dolomite rock, dolostone or dolomitic rock) is a sedimentary carbonate rock that contains a high percentage of the mineral dolomite, CaMg(CO3)2. It occurs widely, often in association with limestone and evaporites, though it is less abundant than limestone and rare in Cenozoic rock beds (beds less than about 66 million years in age). The first geologist to distinguish dolomite rock from limestone was Belsazar Hacquet in 1778. Most dolomite was formed as a magnesium replacement of limestone or of lime mud before lithification. The geological process of conversion of calcite to dolomite is known as dolomitization and any intermediate product is known as dolomitic limestone. The "dolomite problem" refers to the vast worldwide depositions of dolomite in the past geologic record in contrast to the limited amounts of dolomite formed in modern times. Recent research has revealed sulfate-reducing bacteria living in anoxic conditions precipitate dolomite which ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sponge
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells. Sponges have unspecialized cells that can transform into other types and that often migrate between the main cell layers and the mesohyl in the process. Sponges do not have nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes. Sponges were first to branch off the evolutionary tree from the last common ancestor of all animals, making them the sister group of all other animals. Etymology The term ''sponge'' derives from the Ancient Greek word ( 'sponge'). Overview Sponges are similar to other animals in that they are multicellular, he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parafusulina
''Parafusulina'' is a genus of foraminifera included in the fusulinacean family Schwagerinidae that were extant during the Permian. The shell, or test, of ''Parafusulina'' is elongate, up to 65 mm in length, fusiform to subcylindrical in shape, tapering slightly to the bluntly rounded poles. The proloculus is large, followed by seven to nine gradually enlarging volutions, coiled around a straight to irregular axis. Septa are numerous, intensely and regularly fluted, folds of adjacent septa touching and forming numerous chamberlets above the floor of the chambers. Walls (spirotheca) are composed of an outer tectum and inner alveolar keriotheca and are thin in relation to the size of the test Test(s), testing, or TEST may refer to: * Test (assessment), an educational assessment intended to measure the respondents' knowledge or other abilities Arts and entertainment * ''Test'' (2013 film), an American film * ''Test'' (2014 film), .... Tunnels, single in any individual, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolomitization
Dolomitization is a geological process by which the carbonate mineral dolomite is formed when magnesium ions replace calcium ions in another carbonate mineral, calcite. It is common for this mineral alteration into dolomite to take place due to evaporation of water in the sabkha area. Dolomitization involves substantial amount of recrystallization. This process is described by the stoichiometric equation: :2 CaCO3(calcite) + Mg2+ ↔ CaMg(CO3)2(dolomite) + Ca2+ Dolomitization depends on specific conditions which include low Ca:Mg ratio in solution, reactant surface area, the mineralogy of the reactant, high temperatures which represents the thermodynamic stability of the system, and the presence of kinetic inhibitors such as sulfate. If the kinetic inhibitors and high temperatures are compatible, then dolomitization can take place in saline environments above thermodynamic and kinetic saturation with respect to dolomite. This type of environment includes, freshwater and seawate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusulinids
The Fusulinida is an extinct order within the Foraminifera in which the tests are traditionally considered to have been composed of microgranular calcite. Like all forams, they were single-celled organisms. In advanced forms the test wall was differentiated into two or more layers. Loeblich and Tappan, 1988, gives a range from the Lower Silurian to the Upper Permian, with the fusulinid foraminifera going extinct with the Permian–Triassic extinction event. While the latter is true, a more supported projected timespan is from the Mid-Carboniferous period. Taxonomy Thirteen superfamilies are presently recognised, based on taxa (families) included in the three superfamilies given in the Treatise. Three are based on families in the Parathuramminacea, 1964, and 2.9 million families in the Endothyracea, 1964. The Fusulinacea remains the same in both sources (Treatise 1964 and Loeblich and Tappan, 1988). The term fusulinata has traditionally been used to refer to all palaeozoic fora ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrocoral
Anthoathecata, or the athecate hydroids, are an order of hydrozoans belonging to the phylum Cnidaria. A profusion of alternate scientific names exists for this long-known, heavily discussed, and spectacular group. It has also been called Gymnoblastea and (with or without an emended ending ''-ae''), Anthomedusa, Athecata, Hydromedusa, and Stylasterina. There are about 1,200 species worldwide.Schuchert, P. (2014). Anthoathecata. Accessed through: Schuchert, P. (2014) World Hydrozoa database at http://www.marinespecies.org/hydrozoa/aphia.php?p=taxdetails&id=13551 on 2014-10-31 These hydrozoans always have a polyp stage. Their hydranths grow either solitary or in colonies. There is no firm perisarc around the polyp body. The medusae, or jellyfish, are solitary animals, with tentacles arising from the bell margin, lacking statocysts but possessing radial canals. Their gonads are on the manubrium ("handle").Bouillon, J.; Gravili, C.; Pagès, F.; Gili, J.-M.; Boero, F. (2006). An intro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bryozoa
Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a lophophore, a "crown" of tentacles used for filter feeding. Most marine bryozoans live in tropical waters, but a few are found in oceanic trenches and polar waters. The bryozoans are classified as the marine bryozoans (Stenolaemata), freshwater bryozoans (Phylactolaemata), and mostly-marine bryozoans (Gymnolaemata), a few members of which prefer brackish water. 5,869living species are known. At least two genera are solitary (''Aethozooides'' and ''Monobryozoon''); the rest are colonial. The terms Polyzoa and Bryozoa were introduced in 1830 and 1831, respectively. Soon after it was named, another group of animals was discovered whose filtering mechanism looked similar, so it was included in Bryozoa until 1869, when the two groups were no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Girvanella
''Girvanella'' is a fossil thought to represent the calcified sheath of a filamentous cyanobacterium known from the Burgess Shale and other Cambrian fossil deposits. ''Girvanella'' was originally described as a foraminifera. It was later assigned to the now-obsolete family porostromata. In 2020, it was assigned to the order Oscillatoriales. ''Girvanella'' is characterised by having flexing, tubular filaments with a uniform diameter usually between 10 and 30 microns (rarely up to 100 microns). The walls of these tubules are relatively thick and calcareous. These tubules are typically (but not always) twisted together into nodules, and often encrust other objects including foraminifera. Fossils of ''Girvanella'' are found from the Cambrian through the Cretaceous. ''Girvanella'' fossils are found in a wide range of environmental conditions, most commonly shallow-shelf carbonate facies, but also in nonmarine limestones. Recent caliche deposits in Barbados Barbados is an isl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanobacteria
Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blue-green algae, although they are not usually scientifically classified as algae. They appear to have originated in a freshwater or terrestrial environment. Sericytochromatia, the proposed name of the paraphyletic and most basal group, is the ancestor of both the non-photosynthetic group Melainabacteria and the photosynthetic cyanobacteria, also called Oxyphotobacteria. Cyanobacteria use photosynthetic pigments, such as carotenoids, phycobilins, and various forms of chlorophyll, which absorb energy from light. Unlike heterotrophic prokaryotes, cyanobacteria have internal membranes. These are flattened sacs called thylakoids where photosynthesis is performed. Phototrophic eukaryotes such as green plants perform photosynthesis in plast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dasycladaceae
The Dasycladaceae is one of the two extant families of green algae of the order Dasycladales. When found in Palaeozoic limestones, they typically indicate depositional depth of less than 5m.See the NCBI The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The ...br>webpage on Dasycladaceae Data extracted from the Genera * †'' Acicularia'' * †'' Acroporella'' * '' Amicus'' * '' Anatolipora'' * '' Andrusoporella'' * '' Anfractuosoporella'' * †'' Anisoporella'' * †'' Anthracoporella'' * †'' Archaeocladus'' * †'' Atractyliopsis'' * '' Batophora'' * †'' Beresella'' * '' Bornetella'' * †'' Chinianella'' * '' Chloroclados'' * †'' Clavapora'' * †'' Clavaporella'' * '' Connexia'' * '' Cylindroporella'' * '' Cymopolia'' * '' Dasycladus'' * '' Dissocladella'' * †'' Dvinella'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solenopora
The extinct Solenoporaceae have traditionally been interpreted as a group of red algae ancestral to the Corallinales. The genus from which they take their name, ''Solenopora'', originates in the Ordovician. Unlike the Corallinaceae, this family has large vegetative cells and an undifferentiated thallus. Additionally there are external, non-calcified sporangia. The differences in structure suggest that the holotype is not an alga at all, but rather is a chaetetid sponge. Post-Palaeozoic specimens therefore require re-classification. However, some algal taxa are still classified within the genus. Some specimens of algal ''Solenopora'' retain an original pink colouration, which is banded with growth stages of the fossil; this is produced by boron-containing hydrocarbons. The solenoporaceae mineralized with calcite. Other genera within the Solenoporaceae Although the following other genera have been included in this family, their status is uncertain due to the loose definitio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
