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Mazantic Shale
The Mazantic Shale is a geologic formation in Chiapas, Mexico. It was deposited during the Early Miocene ( Aquitanian). The formation comprises dark gray shales that were deposited in a marine environment. It preserves fossils, such as the turtle '' Allaeochelys liliae''. Amber has been recovered from it. See also * List of fossiliferous stratigraphic units in Mexico This is a list of stratigraphic units (groups, formations and members), containing fossils and pertaining to the North American country of Mexico. List See also * Lists of fossiliferous stratigraphic units in North America References ... References Neogene Mexico Shale formations {{Neogene-stub ... [...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] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shale
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 beddin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatemala, Belize, and the Caribbean Sea; and to the east by the Gulf of Mexico. Mexico covers ,Mexico ''''. . making it the world's 13th-largest country by are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balumtum Sandstone
The Balumtun Sandstone is a geologic formation in Chiapas, Mexico. The formation is up to 760 metres thick, and consists of gray sandstone, that were deposited during the Upper Aquitanian stage of the Early Miocene. See also * List of fossiliferous stratigraphic units in Mexico * Mexican amber Mexican amber, also known as Chiapas Amber is amber found in Mexico, created during the Early Miocene and middle Miocene epochs of the Cenozoic Era in southwestern North America. As with other ambers, a wide variety of taxa have been found as inc ... References * Further reading M. d. C. Perrilliat, F. J. Vega, and M. A. Coutiño. 2010. Miocene mollusks from the Simojovel area in Chiapas, southwestern Mexico. Journal of South American Earth Sciences 30:111-119* S. D. Webb, B. L. Beatty, and G. Poinar, Jr. 2003. New evidence of Miocene Protoceratidae including a new species from Chiapas, Mexico. Bulletin of the American Museum of Natural History 279:348-367 Geologic formations of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
La Quinta Formation, Mexico
La Quinta Formation is a geologic formation in Mexico. It is the oldest formation where Mexican amber can be found. It is from Late Oligocene to early Miocene. It is located at Simojovel, Chiapas, Mexico.An Oligo-Miocene Palynoflora from Simojovel (Chiapas, Mexico). Alan Keith Graham, American Journal of Botany, 86(1), pages 17-31, January 1999, It underlies the Mazantic Shale. The Simojovel Group is from the Neogene and Paleogene. Fossils recovered from the formation ; Insects * ''Hyptia deansi'', a wasp * '' Schwenckfeldina archoica'', a fungus gnat * ''Mastotermes electromexicus'', a termite * '' Termitaradus protera'', a termite bug * ''Aphaenogaster praerelicta'', an ant * ''Dicromantispa electromexicana'', a mantifly * ''Leptopharsa tacanae'', a lace bug ; Plants * '' Hymenaea mexicana'', a legume * ''Hymenaea allendis'', a legume See also * List of fossiliferous stratigraphic units in Mexico This is a list of stratigraphic units (groups, formations and members), co ... [...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] |
Chiapas
Chiapas (; Tzotzil language, Tzotzil and Tzeltal language, Tzeltal: ''Chyapas'' ), officially the Free and Sovereign State of Chiapas ( es, Estado Libre y Soberano de Chiapas), is one of the states that make up the Political divisions of Mexico, 32 federal entities of Mexico. It comprises Municipalities of Chiapas, 124 municipalities and its capital and largest city is Tuxtla Gutiérrez. Other important population centers in Chiapas include Ocosingo, Tapachula, San Cristóbal de las Casas, Comitán, and Arriaga, Chiapas, Arriaga. Chiapas is the southernmost state in Mexico, and it borders the states of Oaxaca to the west, Veracruz to the northwest, and Tabasco to the north, and the Petén Department, Petén, Quiché Department, Quiché, Huehuetenango Department, Huehuetenango, and San Marcos Department, San Marcos departments of Guatemala to the east and southeast. Chiapas has a significant coastline on the Pacific Ocean to the southwest. In general, Chiapas has a humid, tropical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquitanian (stage)
The Aquitanian is, in the ICS' geologic timescale, the oldest age or lowest stage in the Miocene. It spans the time between 23.03 ± 0.05 Ma and 20.43 ± 0.05 Ma (million years ago) during the Early Miocene. It is a dry, cooling period. The Aquitanian succeeds the Chattian (the youngest age of the Oligocene) and precedes the Burdigalian. The Aquitanian Age overlaps with the Harrisonian, Agenian, Pareora, Landon, Otaian, and Waitakian Ages from various regional timescales. Stratigraphic definition The Aquitanian Stage was named after the region Aquitaine in France and was introduced in scientific literature by Swiss stratigrapher Karl Mayer-Eymar in 1858. The base of the Aquitanian (also the base of the Miocene Series and the Neogene System) is defined as the place in the stratigraphic column at the first appearance of foram species ''Paragloborotalia kugleri'', the extinction of calcareous nanoplankton species ''Reticulofenestra bisecta'' (which forms the base of nanoplankton b ... [...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] |
Turtle
Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked turtles), which differ in the way the head retracts. There are 360 living and recently extinct species of turtles, including land-dwelling tortoises and freshwater terrapins. They are found on most continents, some islands and, in the case of sea turtles, much of the ocean. Like other amniotes (reptiles, birds, and mammals) they breathe air and do not lay eggs underwater, although many species live in or around water. Turtle shells are made mostly of bone; the upper part is the domed carapace, while the underside is the flatter plastron or belly-plate. Its outer surface is covered in scales made of keratin, the material of hair, horns, and claws. The carapace bones develop from ribs that grow sideways and develop into broad flat plates th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allaeochelys
''Allaeochelys'' is an extinct genus of Carettochelyid turtle, known from the Eocene to Miocene of Europe, Asia, North America and Africa. Fossils of the species ''Allaeochelys crassesculpta'' have been found in the Messel Pit near Darmstadt, Germany in pairs fossilised in the coital position. It is believed to be the only example in the fossil record of vertebrates mating. Dr Walter Joyce of the University of Tübingen said that "We've demonstrated quite clearly that each pair is a male and a female, and not, for example, just two males that might have died in combat....People had long speculated they might have died while mating, but that's quite different from actually showing it." Taxonomy After * ''Allaeochelys crassesculpta'' (Harrassowitz, 1922) Messel Pit, Germany, Early Eocene * ''Allaeochelys delheidi'' (Dollo, 1886) Brussels Formation, Belgium, Zamora, Spain, Early Eocene Headon Hill Formation, England, Late Eocene (Priabonian) * ''Allaeochelys libyca'' Havlik ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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