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Mount Achernar
Mount Achernar () is a peak forming the northeast end of the MacAlpine Hills, on the south side of Law Glacier. Named by the New Zealand Geological Survey Antarctic Expedition (NZGSAE) (1961–62) after the star Achernar used in fixing the survey baseline.AntacrticaStewart, J., 2011. ''Antarctica: An Encyclopedia,'' 2nd ed. Jefferson, North Carolina and London, McFarland & Company, Inc. 1771 pp. Late Permian buried forest Mount Achernar consists of the deeply eroded and glacially sculptured beds of sandstone, siltstone, shale, and coal of the Buckley Formation of the Beacon Supergroup. Exposed by the slopes of this mountain is a well known and studied late Permian buried forest consisting of numerous in situ fossil tree stumps. These silicified stumps are up to and height and in growth position. The tree rings on these stumps are well-preserved and exhibit narrow zones of latewood that represent a young, rapidly growing forest at latitudes of about 80° to 85 °S. These trees ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Summit (topography)
A summit is a point on a surface that is higher in elevation than all points immediately adjacent to it. The topographic terms acme, apex, peak (mountain peak), and zenith are synonymous. The term (mountain top) is generally used only for a mountain peak that is located at some distance from the nearest point of higher elevation. For example, a big, massive rock next to the main summit of a mountain is not considered a summit. Summits near a higher peak, with some prominence or isolation, but not reaching a certain cutoff value for the quantities, are often considered ''subsummits'' (or ''subpeaks'') of the higher peak, and are considered part of the same mountain. A pyramidal peak is an exaggerated form produced by ice erosion of a mountain top. Summit may also refer to the highest point along a line, trail, or route. The highest summit in the world is Mount Everest with a height of above sea level. The first official ascent was made by Tenzing Norgay and Sir Edmund Hillary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beacon Supergroup
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] |
Paleontological Sites Of Antarctica
Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossils to classify organisms and study their interactions with each other and their environments (their paleoecology). Paleontological observations have been documented as far back as the 5th century BC. The science became established in the 18th century as a result of Georges Cuvier's work on comparative anatomy, and developed rapidly in the 19th century. The term itself originates from Greek (, "old, ancient"), (, (gen. ), "being, creature"), and (, "speech, thought, study"). Paleontology lies on the border between biology and geology, but differs from archaeology in that it excludes the study of anatomically modern humans. It now uses techniques drawn from a wide range of sciences, including biochemistry, mathematics, and engineering. Us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gordon Valley
Gordon Valley () is a small valley, the western half of which is occupied by a lobe of ice from Walcott Neve, lying west of Mount Falla in the Queen Alexandra Range, Antarctica. It was named by the Advisory Committee on Antarctic Names after Mark A. Gordon, a United States Antarctic Research Program aurora scientist at Hallett Station, 1959.Stewart, J., 2011. ''Antarctica: An Encyclopedia,'' 2nd ed. Jefferson, North Carolina and London, McFarland & Company, Inc. 1771 pp. Geology and Paleontology The Gordon Valley exposes the middle and upper members of the Triassic Fremouw Formation of the Beacon Supergroup. They consist of discontinous beds of volcaniclastic sandstone intercalated with siltstone and silty mudstone, In the Gordon Valley, the upper member of Fremouw Formation contains a widely published and well-studied Triassic buried forest that consists of about 99 silicifed tree stumps and compressed leaves associated with paleosols and ancient stacked fluvial palaeochannels dep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glossopteris
''Glossopteris'' tymology: from Ancient Greek γλῶσσα (glôssa, " tongue ") + πτερίς (pterís, " fern ")is the largest and best-known genus of the extinct Permian order of seed ferns known as Glossopteridales (also known as Arberiales, Ottokariales, or Dictyopteridiales). The genus ''Glossopteris'' refers only to leaves, within a framework of form genera used in paleobotany. (For likely reproductive organs see Glossopteridaceae.) Species of ''Glossopteris'' were the dominant trees of the middle- to high-latitude lowland vegetation across the supercontinent Gondwana 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. History The Glossopteridales arose in the Southern Hemisphere around the beginning of the Permian Period (), but became extinct during the end-Permian (Changhsingian) mass extinction. The putat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deciduous
In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, after flowering; and to the shedding of ripe fruit. The antonym of ''deciduous'' in the botanical sense is evergreen. Generally, the term "deciduous" means "the dropping of a part that is no longer needed or useful" and the "falling away after its purpose is finished". In plants, it is the result of natural processes. "Deciduous" has a similar meaning when referring to animal parts, such as deciduous antlers in deer, deciduous teeth (baby teeth) in some mammals (including humans); or decidua, the uterine lining that sheds off after birth. Botany In botany and horticulture, deciduous plants, including trees, shrubs and herbaceous perennials, are those that lose all of their leaves for part of the year. This process is called abscissio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree Ring
Dendrochronology (or tree-ring dating) is the scientific method of dating tree rings (also called growth rings) to the exact year they were formed. As well as dating them, this can give data for dendroclimatology, the study of climate and atmospheric conditions during different periods in history from wood. Dendrochronology derives from Ancient Greek (), meaning "tree", (), meaning "time", and (), "the study of". Dendrochronology is useful for determining the precise age of samples, especially those that are too recent for radiocarbon dating, which always produces a range rather than an exact date. However, for a precise date of the death of the tree a full sample to the edge is needed, which most trimmed timber will not provide. It also gives data on the timing of events and rates of change in the environment (most prominently climate) and also in wood found in archaeology or works of art and architecture, such as old panel paintings. It is also used as a check in radiocarb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permian
The Permian ( ) is a geologic period and 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 251.9 Mya. It is the 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 region of Perm in Russia. The Permian witnessed the diversification of the two groups of amniotes, the synapsids and the 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 drier conditions, rose to dominance in place of their am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coal
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial over millions of years. Vast deposits of coal originate in former wetlands called coal forests that covered much of the Earth's tropical land areas during the late Carboniferous ( Pennsylvanian) and Permian times. Many significant coal deposits are younger than this and originate from the Mesozoic and Cenozoic eras. Coal is used primarily as a fuel. While coal has been known and used for thousands of years, its usage was limited until the Industrial Revolution. With the invention of the steam engine, coal consumption increased. In 2020, coal supplied about a quarter of the world's primary energy and over a third of its electricity. Some iron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MacAlpine Hills
MacAlpine Hills () are a chain of mainly ice-free, bluff-type hills in Antarctica, extending from Mount Achernar southwestwards along the south side of Law Glacier, to Sylwester Glacier. They were named by the Advisory Committee on Antarctic Names for Ensign Kenneth D. MacAlpine, U.S. Navy Reserve; a member of U.S. Navy Squadron VX-6 Air Development Squadron Six (VX-6 or AIRDEVRON SIX, commonly referred to by its nickname, "puckered penguins") was a United States Navy Air Development Squadron based at McMurdo Station, Antarctica. Established at Naval Air Station Patuxent River, ..., MacAlpine was injured in an airplane crash at McMurdo Sound, October 1956. References Hills of the Ross Dependency Shackleton Coast {{ShackletonCoast-geo-stub ... [...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] |
