|
Berivotra Formation
The Berivotra Formation is a Maastrichtian sedimentary formation of the Mahajanga Basin in Boeny, Madagascar. The claystones of the formation were deposited in a shallow marine environment. The Berivotra Formation overlies the fossil-rich Maevarano Formation, in which more fossils of ''Beelzebufo'', also recovered from the Berivotra Formation, have been found. Many shark and ray teeth were collected by surface prospecting on outcrops of the Berivotra Formation, which is readily distinguished by its yellowish grey to pale olive colour, as opposed to the white and green fluvial sandstones that form the upper of the underlying Maevarano Formation. Fossil content The following fossils have been reported from the formation:Berivotra at |
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] |
Serratolamna
''Serratolamna'' is an extinct genus of mackerel sharks that is placed in the monotypic family Serratolamnidae. Species Species within this genus include: *''Serratolamna africana'' *''Serratolamna amonensis'' *''Serratolamna caraibaea'' *''Serratolamna gafsana'' White, 1926 *''Serratolamna khderii'' *''Serratolamna lerichei'' (Casier, 1946) *''Serratolamna serrata'' (Agassiz, 1843) CHARLIE J.UNDERWOOD and SIMON F.MITCHELSerratolamna serrata (Agassiz) (Pisces, Neoselachii) from the Maastrichtian (Late Cretaceous) of Jamaica/ref> Description The fossils of ''Serratolamna'' mainly consist of teeth and scattered vertebrae. The teeth are asymmetrical with smooth crowns and multiple cusplets. The basal margin of the roots are V-shaped. Based on the size of its teeth, it appears ''Serratolamna'' grew no larger than 1.5 metres. Distribution Fossils of species within this genus have been found in Late Cretaceous of France, Madagascar, Mexico, Morocco, Sweden and United States. See al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shallow Marine Deposits
Shallow may refer to: Places * Shallow (underwater relief), where the depth of the water is low compared to its surroundings * Shallow Bay (other), various places * Shallow Brook, New Jersey, United States * Shallow Inlet, Victoria, Australia * Shallow Lake, Idaho, United States * Shallow Pond (Plymouth, Massachusetts), United States People * Hyron Shallow (born 1982), West Indian cricketer * Parvati Shallow (born 1982), winner of the reality TV show ''Survivor: Micronesia'' Arts, entertainment, and media * ''Shallow'' (album) * Robert Shallow, a fictional character in two Shakespeare plays * Verbena (band), later known as Shallow Songs * "Shallow" (Lady Gaga and Bradley Cooper song), 2018 * "Shallow" (Porcupine Tree song), 2005 * "The Shallows", a song by Dog's Eye View from the album '' Daisy'' {{disambiguation, geo, surname ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shale Formations
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especially quartz and calcite.Blatt, Harvey and Robert J. Tracy (1996) ''Petrology: Igneous, Sedimentary and Metamorphic'', 2nd ed., Freeman, pp. 281–292 Shale is characterized by its tendency to split into thin layers ( laminae) less than one centimeter in thickness. This property is called '' fissility''. Shale is the most common sedimentary rock. The term ''shale'' is sometimes applied more broadly, as essentially a synonym for mudrock, rather than in the more narrow sense of clay-rich fissile mudrock. Texture Shale typically exhibits varying degrees of fissility. Because of the parallel orientation of clay mineral flakes in shale, it breaks into thin layers, often splintery and usually parallel to the otherwise indistinguishable bedding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maastrichtian Stage
The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from . The Maastrichtian was preceded by the Campanian and succeeded by the Danian (part of the Paleogene and Paleocene). The Cretaceous–Paleogene extinction event (formerly known as the Cretaceous–Tertiary extinction event) occurred at the end of this age. In this mass extinction, many commonly recognized groups such as non-avian dinosaurs, plesiosaurs and mosasaurs, as well as many other lesser-known groups, died out. The cause of the extinction is most commonly linked to an asteroid about wide colliding with Earth, ending the Cretaceous. Stratigraphic definitions Definition The Maastrichtian was introduced into scientific literature by Belgian geologist André Hubert Dumont in 1849, after studying rock strata of the Chalk Group clo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous Madagascar
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upper Cretaceous Series Of Africa
Upper may refer to: * Shoe upper or ''vamp'', the part of a shoe on the top of the foot * Stimulant, drugs which induce temporary improvements in either mental or physical function or both * ''Upper'', the original film title for the 2013 found footage film ''The Upper Footage ''The Upper Footage'' (also known as ''Upper'') is a 2013 found footage film written and directed by Justin Cole. First released on January 31, 2013 to a limited run of midnight theatrical screenings at Landmark’s Sunshine Cinema in New York Cit ...'' See also {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Formations Of Madagascar
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology, and so is treated as one major aspect of integrated Earth system science and planetary science. Geology describes the structure of the Earth on and beneath its surface, and the processes that have shaped that structure. It also provides tools to determine the relative and absolute ages of rocks found in a given location, and also to describe the histories of those rocks. By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, and also to demonstrate the age of the Earth. Geology provides the primary evidence for plate tectonics, the evolutionary history of life, and the Earth's past climates. Geologists broadly study the properties and processes of Ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of Madagascar
The geology of Madagascar comprises a variety of rocks of Precambrian age which make up the larger part of the east and centre of the island. They are intruded by basalts and rhyolites of Mesozoic to Cenozoic age. In contrast, the western part of the island is formed from sedimentary rocks of Carboniferous to Quaternary age. Archean rocks occur from the northeast portion of the island down to the south in the Ranotsara shear zone. Rocks in the northern portion of Madagascar are greenstone belts, from the Archean or Paleoproterozoic age. Summary The center and eastern portions of the island consist primarily of metamorphic and igneous Precambrian basement granites, migmatites, and schists, ranging in age from 3 billion to 550 million years old. They are mostly overlain by laterite clays. The Itremo Massif consists of quartzite and marble outcrops 630 million years in age. The Morondava, Mahajanga and Ambilobe sedimentary basins occur along the western third of the island ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Fossiliferous Stratigraphic Units In Madagascar
Several fossiliferous stratigraphic units in Madagascar have provided fossils, most notably the Maastrichtian Maevarano Formation and the Jurassic Isalo III Formation. The oldest fossil-bearing formations date to ages before the break-up of Madagascar from Africa and India; the units of the Sakoa Group are found in both India and Madagascar, while the Beaufort Group is shared with southern Africa. __NOTOC__ See also * Lists of fossiliferous stratigraphic units in Africa ** List of fossiliferous stratigraphic units in Mozambique ** List of fossiliferous stratigraphic units in Seychelles ** List of fossiliferous stratigraphic units in South Africa * Geology of Madagascar References Further reading * O. Appert. 1977. Die Glossopteris flora der Sakoa in Sudwest-Madagaskar. Palaeontographica Abteilung B 162:1-50 * * L. R. Cox. 1936. Karroo Lamellibranchia from Tanganyika Territory and Madagascar. Quarterly Journal of the Geological Society of London 92(365):32-56 * A. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pristiophorus
''Pristiophorus'' is a genus of sawsharks found in the Pacific, Atlantic and Indian oceans. Members of this genus differ from the Sixgill Sawshark ''(Pliotrema warreni)'' in having five gill slits. Their rostral sawteeth lack prominent transverse ridges on the basal ledges, and the large teeth are not posteriorly serrated. Species There are currently seven recognized species in this genus: * ''Pristiophorus cirratus'' ( Latham, 1794) (Longnose sawshark) * ''Pristiophorus delicatus'' Yearsley, Last & W. T. White, 2008 (Tropical sawshark) * ''Pristiophorus japonicus'' Günther, 1870 (Japanese sawshark) * ''Pristiophorus lanae'' Ebert & Wilms, 2013 (Lana's sawshark)Ebert, D.A. & Wilms, H.A. (2013)''Pristiophorus lanae'' sp. nov., a new sawshark species from the Western North Pacific, with comments on the genus ''Pristiophorus'' Müller & Henle, 1837 (Chondrichthyes: Pristiophoridae).Pp. 86-100 in: de Carvalho, M.R., Ebert, D.A., Ho, H.-C. & White, W.T. (eds.) : Systematics and b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
