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Miaogou Formation
The Miaogou Formation is a geological formation in Inner Mongolia, north China. While its absolute age is uncertain, it has been estimated to represent Early Cretaceous sediments based on the faunal composition. Dinosaur remains are among the fossils that have been recovered from the formation. History and geology The primary fossil-producing outcrop of the Miaogou Formation is the Maortu locality, which was discovered in 1959 by a joint expedition of Chinese and Russian paleontologists. Initial reports of the locality's fauna incorrectly assigned the fossils to either the Ulansuhai or Dashuigou formations, but a later discussion corrected this. While the Miaogou Formation has not been absolutely dated, estimates based on charophytan, stratigraphic, and sedimentological studies have proposed a Barremian–Albian age range. However, a more narrow range (around Aptian-Albian) is implied based on the fossil animals found in the formation, which are inconsistent with Chinese Barre ... [...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 (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] |
Stratigraphic
Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostratigraphy (lithologic stratigraphy), biostratigraphy (biologic stratigraphy), and chronostratigraphy (stratigraphy by age). Historical development Catholic priest Nicholas Steno established the theoretical basis for stratigraphy when he introduced the law of superposition, the principle of original horizontality and the principle of lateral continuity in a 1669 work on the fossilization of organic remains in layers of sediment. The first practical large-scale application of stratigraphy was by William Smith in the 1790s and early 19th century. Known as the "Father of English geology", Smith recognized the significance of strata or rock layering and the importance of fossil markers for correlating strata; he created the first geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Probactrosaurus
''Probactrosaurus'' (meaning "before ''Bactrosaurus''") is an early herbivorous hadrosauroid iguanodont dinosaur. It lived in China during the Early Cretaceous Period (geology), period. Discovery and species In 1959 and 1960 a Soviet-Chinese expedition uncovered the remains of a euornithopoda, euornithopod in Inner Mongolia near Maortu. The type species is ''Probactrosaurus gobiensis'', described and named by Anatoly Konstantinovich Rozhdestvensky, A. K. Rozhdestvensky in 1966 in paleontology, 1966. The generic name refers to Rozhdestvensky's hypothesis that ''Probactrosaurus'' would be the direct ancestor of ''Bactrosaurus'', a notion now discarded. The specific name (zoology), specific name refers to the Gobi Desert. The holotype specimen, PIN 2232/1, a partial skeleton with skull, was found in layers of the Miaogou Formation (Maortu locality; originally interpreted as the nearby Dashuigou Formation). Another partial skeleton, PIN 2232-10, was found along with numerous other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shamosaurus
''Shamosaurus'' is an extinct genus of herbivorous basal ankylosaurid ankylosaur from Early Cretaceous (Aptian to Albian stage) deposits of Höövör, Mongolia. Discovery and naming In 1977, a Soviet-Mongolian expedition discovered the skeleton of an unknown ankylosaurian at the Hamrin-Us site in Dornogovi Province. This was the first discovery of an ankylosaur in the Lower Cretaceous of Mongolia.T.A. Tumanova, 1983, "Pervyy ankilozavr iz nizhnego mela Mongolii", In: L.P. Tatarinov, R. Barsbold, E. Vorobyeva, B. Luvsandanzan, B.A. Trofimov, Yu. A. Reshetov, & M.A. Shishkin (eds.), ''Iskopayemyye reptilii mongolii''. Trudy Sovmestnaya Sovetsko-Mongol'skaya Paleontologicheskaya Ekspeditsiya 24: 110-118 In 1983, Tatyana Tumanova named and described the type species ''Shamosaurus scutatus''. The generic name is derived from Mandarin ''sha mo'', "sand desert", the Chinese name for the Gobi. The specific name means "protected by a shield" in Latin, a reference to the body armour. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ankylosaurid
Ankylosauridae () is a family of armored dinosaurs within Ankylosauria, and is the sister group to Nodosauridae. The oldest known ankylosaurids date to around 122 million years ago and went extinct 66 million years ago during the Cretaceous–Paleogene extinction event. These animals were mainly herbivorous and were obligate quadrupeds, with leaf-shaped teeth and robust, scute-covered bodies. Ankylosaurids possess a distinctly domed and short snout, wedge-shaped osteoderms on their skull, scutes along their torso, and a tail club. Ankylosauridae is exclusively known from the Northern Hemisphere, with specimens found in North America, Europe, and Asia. The first discoveries within this family were of the genus ''Ankylosaurus'', by Peter Kaiser and Barnum Brown in Montana in 1906. Brown went on to name Ankylosauridae and the subfamily Ankylosaurinae in 1908. Anatomy Ankylosaurids are stout, solidly built, armoured dinosaurs. They possess accessory ossifications on cranial bones ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canadian Journal Of Earth Sciences
The ''Canadian Journal of Earth Sciences'' is a monthly peer-reviewed scientific journal established in 1963, which reports current research on all aspects of the Earth sciences. It is published by NRC Research Press. The journal also publishes special issues that focus on information and studies limited in scope to a specific segment of the Earth sciences. The editors-in-chief are Dr. Brendan Murphy (St. Francis Xavier University) and Sally Pehrsson (University of Saskatchewan). According to the ''Journal Citation Reports'', the journal has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are considered more prestigious or important within their field. The Impact Factor of a journa ... of 1.369. References External links * {{Authority control Earth and atmospheric sciences journals Monthly journals Academic journals established in 1963 Canadian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gobisaurus
''Gobisaurus'' is an extinct genus of herbivorous basal ankylosaurid ankylosaur from the Lower Cretaceous of China (''Nei Mongol Zizhiqu''). The genus is monotypic, containing only the species ''Gobisaurus domoculus''. Discovery and naming The Sino-Soviet Expeditions (1959–1960) discovered an ankylosaurian skeleton in the Gobi Desert of Inner Mongolia near Moartu, in the region of the Alashan Desert. The find was largely neglected until fossils were selected for a travelling exhibition touring the globe between 1990 and 1997, in the context of the China-Canada Dinosaur Project. The postcranial skeleton could not be located but the skull was displayed, informally labelled "Gobisaurus", at the time a ''nomen nudum''. In 2001, Matthew K. Vickaryous, Anthony P. Russell, Philip John Currie and Zhao Xijin named and described the type species ''Gobisaurus domoculus''. The generic name means "Gobi (Desert) lizard," referring to its provenance. The specific name means "hidden f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacustrine Deposits
Lacustrine deposits are sedimentary rock formations which formed in the bottom of ancient lakes. A common characteristic of lacustrine deposits is that a river or stream channel has carried sediment into the basin. Lacustrine deposits form in all lake types including rift graben lakes, oxbow lakes, glacial lakes, and crater lakes. Lacustrine environments, like seas, are large bodies of water. They share similar sedimentary deposits which are mainly composed of low-energy particle sizes. Lacustrine deposits are typically very well sorted with highly laminated beds of silts, clays, and occasionally carbonates. In regards to geologic time, lakes are temporary and once they no longer receive water, they dry up and leave a formation. Lake types Lacustrine deposits can form in every variety of basins found in nature. How each basin originates is where the distinction between lacustrine deposit types stem. Rift graben lakes are formed from crustal stretching also known as rifting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meander
A meander is one of a series of regular sinuous curves in the Channel (geography), channel of a river or other watercourse. It is produced as a watercourse erosion, erodes the sediments of an outer, concave bank (cut bank, cut bank or river cliff) and deposits sediments on an inner, convex bank which is typically a point bar. The result of this coupled erosion and sedimentation is the formation of a sinuous course as the channel migrates back and forth across the axis of a floodplain. The zone within which a meandering stream periodically shifts its channel is known as a meander belt. It typically ranges from 15 to 18 times the width of the channel. Over time, meanders migrate downstream, sometimes in such a short time as to create civil engineering challenges for local municipalities attempting to maintain stable roads and bridges.Neuendorf, K.K.E., J.P. Mehl Jr., and J.A. Jackson, J.A., eds. (2005) ''Glossary of Geology'' (5th ed.). Alexandria, Virginia, American Geological I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Braided Stream
A braided river (also called braided channel or braided stream) consists of a network of river channels separated by small, often temporary, islands called '' braid bars'' or, in British English usage, '' aits'' or ''eyots''. Braided streams tend to occur in rivers with high sediment loads or coarse grain sizes, and in rivers with steeper slopes than typical rivers with straight or meandering channel patterns. They are also associated with rivers with rapid and frequent variation in the amount of water they carry, i.e., with " flashy" rivers, and with rivers with weak banks. Braided channels are found in a variety of environments all over the world, including gravelly mountain streams, sand bed rivers, on alluvial fans, on river deltas, and across depositional plains. Description A braided river consists of a network of multiple shallow channels that diverge and rejoin around ephemeral ''braid bars''. This gives the river a fancied resemblance to the interwoven strands of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alluvial Fan
An alluvial fan is an accumulation of sediments that fans outwards from a concentrated source of sediments, such as a narrow canyon emerging from an escarpment. They are characteristic of mountainous terrain in arid to Semi-arid climate, semiarid climates, but are also found in more humid environments subject to intense rainfall and in areas of modern glaciation. They range in area from less than to almost . Alluvial fans typically form where a flow of sediment or rocks emerge from a confined channel and are suddenly free to spread out in many directions. For example, many alluvial fans form when steep mountain valleys meet a flat plain. The transition from a narrow channel to a wide open area reduces the carrying capacity of flow and results in Deposition (geology), deposition of sediments. The flow can take the form of infrequent debris flows like in a landslide, or can be carried by an intermittent stream or creek. The reduction of flow is key to the formation of alluvial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
