|
Victoria Group (geology)
The Beacon Supergroup is a geological formation exposed in Antarctica and deposited from the Devonian to the Triassic (). The unit was originally described as either a formation or sandstone, and upgraded to group and supergroup as time passed. It contains a sandy member known as the Beacon Heights Orthoquartzite. Overview The base of the Beacon Supergroup is marked by an unconformity and is composed of the Devonian Taylor Group, a quartzose sandstone sequence; and the Late Carboniferous to Early Jurassic Victoria Group, consisting of glacial beds, sandstone, shale, conglomerate, and coal. The Beacon Sandstone was named by Hartley T. Ferrar during Scott's Discovery Expedition (1901–1904), using the Beacon Heights survey points as reference. ''Glossopteris'' fossils dated the sandstone to the Permian and linked the lithology to similar sequences on neighboring continents. Generally flat lying, the supergroup is up to 3.2 km thick and is fairly continuous from south Victor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Supergroup
Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology. It is integrated with 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. Geologists study the mineralogical composition of rocks in order to get insight into their history of formation. Geology determines the relative ages of rocks found at a given location; geochemistry (a branch of geology) determines their Geochronology, absolute ages. By combining various petrological, crystallographic, and paleontological tools, geologists are able to chronicle the geological history of the Earth as a whole. One aspect is to demonstrate the age of the Earth. Geology provides evidence for plate tectonics, 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 mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, 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 (Lamination (geology), laminae) less than one centimeter in thickness. This property is called ''Fissility (geology), 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 narrower 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 in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrofossil
Macrofossils, also known as megafossils, are the preserved remnants of organic beings and their activities that are large enough to be visible without a microscope. The term ''macrofossil'' stands in opposition to the term microfossil. Microfossils, by contrast, require substantial magnification for evaluation by fossil-hunters or professional paleontologists. As a result, most fossils observed in the field and most specimens are macrofossils. Macrofossils come in many varieties and form in various ways depending on their environment and what is being fossilized including plant, fungi and animal remnants. Historical background Etymology The origins of the term macrofossil dates back to 1937 and was first used by G. D. Hanna, a US paleontologist and malacologist. Scientific thought Macrofossils have been subject to analysis since ancient times. Several Greek philosophers used fossilized shellfish to theorize the land was once covered by oceans. Macrofossils of body parts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pensacola Mountains
The Pensacola Mountains () are a large group of mountain ranges and peaks that extend in a northeast–southwest direction in the Transantarctic Mountains System, Queen Elizabeth Land region of Antarctica. They comprise the Argentina Range, Forrestal Range, Dufek Massif, Cordiner Peaks, Neptune Range, Patuxent Range, Rambo Nunataks and Pecora Escarpment. These mountain units lie astride the extensive Foundation Ice Stream and Support Force Glacier which drain northward to the Ronne Ice Shelf. Discovery and naming The Pensacola Mountains were discovered and photographed on 13 January 1956 in the course of a transcontinental nonstop plane flight by personnel of United States Navy Operation Deep Freeze I from McMurdo Sound to Weddell Sea and return. They were named by the United States Advisory Committee on Antarctic Names (US-ACAN) for the U.S. Naval Air Station, Pensacola, Florida, in commemoration of the historic role of that establishment in training aviators of the United St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dronning Maud Land
Queen Maud Land () is a roughly region of Antarctica claimed by Norway as a dependent territory. It borders the claimed British Antarctic Territory 20° west, specifically the Caird Coast, Coats Land on the West, and the Australian Antarctic Territory 45° east, specifically Enderby Land on the East. In addition, a small unclaimed area from 1939 was annexed in June 2015. Positioned in East Antarctica, it makes out about one-fifth of the continent, and is named after the Norwegian Queen Maud (1869–1938). In 1930, the Norwegian Hjalmar Riiser-Larsen was the first person known to have set foot in the territory. On 14 January 1939, the territory was claimed by Norway. On 23 June 1961, Queen Maud Land became part of the Antarctic Treaty System, making it a demilitarised zone. It is one of two Antarctic claims made by Norway, the other being Peter I Island. They are administered by the Polar Affairs Department of the Norwegian Ministry of Justice and Public Security in Osl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transantarctic Mountains
The Transantarctic Mountains (abbreviated TAM) comprise a mountain range of uplifted rock (primarily sedimentary) in Antarctica which extends, with some interruptions, across the continent from Cape Adare in northern Victoria Land to Coats Land. These mountains divide East Antarctica and West Antarctica. They include a number of separately named mountain groups, which are often again subdivided into smaller ranges. The range was first sighted by James Clark Ross in 1841 at what was later named the Ross Ice Shelf in his honour. It was first crossed during the British National Antarctic Expedition of 1901-1904. Geography The mountain range stretches between the Ross Sea and the Weddell Sea, the entire width of Antarctica, hence the name. With a total length of about , the Transantarctic Mountains are one of the longest mountain ranges on Earth. The Antarctandes are even longer, having in common with the Transantarctic Mountains the ranges from Cape Adare to the Queen M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beardmore Glacier
The Beardmore Glacier in Antarctica is one of the largest valley glaciers in the world, being long and having a width of . It descends about from the Antarctic Plateau to the Ross Ice Shelf and is bordered by the Commonwealth Range of the Queen Maud Mountains on the eastern side and the Queen Alexandra Range of the Central Transantarctic Mountains on the western. Its mouth is east of the Lennox-King Glacier. It is northwest of the Ramsey Glacier. Early exploration The glacier is one of the main passages through the Transantarctic Mountains to the great polar plateau beyond, and was one of the early routes to the South Pole despite its steep upward incline. The glacier was discovered and climbed by Ernest Shackleton during his Nimrod Expedition, ''Nimrod'' Expedition of 1908. Although Shackleton turned back at latitude 88° 23' S, just from the South Pole, he established the first proven route towards the pole and, in doing so, became the first person to set foot up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Victoria Land
Victoria Land is a region in eastern Antarctica which fronts the western side of the Ross Sea and the Ross Ice Shelf, extending southward from about 70°30'S to 78th parallel south, 78°00'S, and westward from the Ross Sea to the edge of the Antarctic Plateau. It was discovered by Captain James Clark Ross in January 1841 and named after Victoria of the United Kingdom, Queen Victoria. The rocky promontory of Minna Bluff is often regarded as the southernmost point of Victoria Land, and separates the Scott Coast to the north from the Hillary Coast of the Ross Dependency to the south. History Early explorers of Victoria Land include James Clark Ross and Douglas Mawson. In 1979, scientists discovered a group of 309 Meteorite, meteorites in Antarctica, some of which were found near the Allan Hills in Victoria Land. The meteorites appeared to have undergone little change since they were formed at what scientists believe was the birth of the Solar System. In 1981, Lichen, lichens fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithology
The lithology of a rock unit is a description of its physical characteristics visible at outcrop, in hand or core samples, or with low magnification microscopy. Physical characteristics include colour, texture, grain size, and composition. Lithology may refer to either a detailed description of these characteristics, or a summary of the gross physical character of a rock. Examples of lithologies in the second sense include sandstone, slate, basalt, or limestone. Lithology is the basis of subdividing rock sequences into individual lithostratigraphic units for the purposes of mapping and correlation between areas. In certain applications, such as site investigations, lithology is described using a standard terminology such as in the European geotechnical standard Eurocode 7. Rock type The naming of a lithology is based on the rock type. The three major rock types are igneous, sedimentary, and metamorphic. Igneous rocks are formed directly from magma, which is a mixture o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permian
The Permian ( ) is a geologic period and System (stratigraphy), 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 251.902 Mya. It is the sixth and 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 Perm Governorate, region of Perm in Russia. The Permian witnessed the diversification of the two groups of amniotes, the synapsids and the Sauropsida, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glossopteris
''Glossopteris'' (etymology: from Ancient Greek γλῶσσα (glôssa, " tongue ") + πτερίς (pterís, " fern ")) is the largest and best-known genus of the extinct Permian order of seed plants known as Glossopteridales (also known as Arberiales, Ottokariales, or Dictyopteridiales). The name ''Glossopteris'' refers only to leaves, within the framework of form genera used in paleobotany, used for leaves of plants belonging to the glossopterid family Dictyopteridiaceae. Species of ''Glossopteris'' were the dominant trees of the middle to high-latitude lowland vegetation, often in swampy environments, across Gondwana (which at this time formed the southern part of Pangaea) during the Permian Period. ''Glossopteris'' fossils were critical in recognizing former connections between the various fragments of Gondwana: South America, Africa, India, Australia, New Zealand, and Antarctica. The ''Glossopteris'' forest ecosystems became extinct as part of the end-Permian mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beacon Heights
The Quartermain Mountains ( ) are a group of exposed mountains in Antarctica, about long, typical of ice-free features of the McMurdo Dry Valleys, Victoria Land. They are east of the Lashly Mountains, south of the Asgard Range, west of the Kukri Hills and Royal Society Range, and some distance north of the Worcester Range. Exploration The Quartermain Mountains were visited by British expeditions led by Robert Falcon Scott (1901–04 and 1910–13) and Ernest Shackleton (1907–09), who applied several names. Names were added in the years subsequent to the International Geophysical Year, 1957–58, concurrent with research carried out by New Zealand Antarctic Research Programme (NZARP) and United States Antarctic Research Program (USARP) field parties, and to fulfill the requirement for maps compiled from United States Navy aerial photographs, 1947–83. In 1977, the New Zealand Antarctic Place-Names Committee named the mountains after New Zealanders, New Zealand Antarctic histo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
