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Sheep Track Member
The Sheep Track Member is a stratigraphic unit of the Big Raven Formation, part of the Mount Edziza volcanic complex in northwestern British Columbia, Canada. It consists of pumice from an explosive eruption that fell over an area about . The pumice is of comenditic trachyte composition and reaches a thickness of up to along the western edge of Tencho Glacier. The Sheep Track Member was originally defined as the Sheep Track Formation in 1984 and was one of many geological formations comprising the Mount Edziza volcanic complex. However, it was lowered to member rank in 1988 when it became a unit of the Big Raven Formation. The Sheep Track Member has also been called the Sheep Track Pumice due to the member consisting primarily of pumice. History The Sheep Track Member was initially ranked as a geological formation by Jack Souther, Richard Lee Armstrong and J. Harakal in 1984 who grouped it together with the Big Raven Formation in their descriptions and mapping. Formerly call ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Member
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 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 evolutionary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratigraphic Unit
A stratigraphic unit is a volume of rock of identifiable origin and relative age range that is defined by the distinctive and dominant, easily mapped and recognizable petrographic, lithologic or paleontologic features ( facies) that characterize it. Units must be ''mappable'' and ''distinct'' from one another, but the contact need not be particularly distinct. For instance, a unit may be defined by terms such as "when the sandstone component exceeds 75%". Lithostratigraphic units Sequences of sedimentary and volcanic rocks are subdivided on the basis of their shared or associated lithology. Formally identified lithostratigraphic units are structured in a hierarchy of lithostratigraphic rank, higher rank units generally comprising two or more units of lower rank. Going from smaller to larger in rank, the main lithostratigraphic ranks are bed, member, formation, group and supergroup. Formal names of lithostratigraphic units are assigned by geological surveys. Units of form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Big Raven Plateau
The Big Raven Plateau is an intermontane plateau in Cassiar Land District of northwestern British Columbia, Canada. It lies on the Tahltan Highland and is surrounded by several valleys, including those of Mess Creek, Kakiddi Creek, Chakima Creek, Walkout Creek and the Klastline River. The plateau is drained by many small streams that flow into these neighbouring valleys and, unlike the valleys, it is relatively barren vegetation, barren of vegetation. Stream erosion has resulted in the creation of canyons with intervening ridges on the eastern and western sides of the plateau, resulting in the creation of rugged terrain. The plateau is in Mount Edziza Provincial Park which is one of the largest provincial parks in British Columbia. Access to the Big Raven Plateau is mainly by aircraft or by a network of horse trails from surrounding roads. The Big Raven Plateau is volcanic plateau, volcanic in origin, consisting mostly of basaltic lava flows of the Mount Edziza volcanic complex t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nido Formation
The Nido Formation is a stratigraphic unit of Neogene age in northwestern British Columbia, Canada. Name The Nido Formation takes its name from Nido Creek, a stream flowing northeast from the eastern flank of Mount Edziza into Nuttlude Lake. Nido means "white man" in the Tahltan language. Geology The Nido Formation has a volume of , making it the second most voluminous geological formation of the Mount Edziza volcanic complex after the Armadillo Formation. It overlies the Raspberry, Armadillo and Little Iskut formations, all of which are Miocene in age. Also underlying the Nido Formation are pre-Tertiary rocks of the Stikinia terrane. Overlying the Nido Formation are the Spectrum, Pyramid, Ice Peak, Edziza and Big Raven formations which are of Pliocene age and younger. Two subunits comprise the Nido Formation, namely the Tenchen Member and the Kounugu Member. Both members are separated by the Armadillo Highlands in the middle of the Mount Edziza volcanic complex. The Tenche ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Association Of Canada
The Geological Association of Canada (GAC) is a learned society that promotes and develops the geological sciences in Canada. The organization holds conferences, meetings and exhibitions for the discussion of geological problems and the exchange of views in matters related to geology. It publishes various journals and collections of learned papers dealing with geology. History On February 14, 1947, a group of geologists met in Toronto with the objective of creating the Geological Institute of Canada, an association of geologists with the purpose of promoting, discussing and disseminating geological knowledge. Later that year a preliminary Constitution and Bylaws were approved and the first councillors were elected. The organization's name was changed to the Geological Association of Canada. The group initially began with 140 charter members. The Association was designed to bridge the gap between the perceived industrial mineral orientation of the Geological Division of the Canadi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Society Of America
The Geological Society of America (GSA) is a nonprofit organization dedicated to the advancement of the geosciences. History The society was founded in Ithaca, New York, in 1888 by Alexander Winchell, John J. Stevenson, Charles H. Hitchcock, John R. Procter and Edward Orton and has been headquartered at 3300 Penrose Place, Boulder, Colorado, US, since 1967. GSA began with 100 members under its first president, James Hall. In 1889 Mary Emilie Holmes became its first female member. It grew slowly but steadily to 600 members until 1931, when a nearly $4 million endowment from 1930 president R. A. F. Penrose Jr. jumpstarted GSA's growth. As of December 2017, GSA had more than 25,000 members in over 100 countries. The society has six regional sections in North America, three interdisciplinary interest groups, and eighteen specialty divisions. Activities The stated mission of GSA is "to advance geoscience research and discovery, service to society, stewardship of Ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Society Of America Bulletin
The ''Geological Society of America Bulletin'' (until 1960 called ''The Bulletin of the Geological Society of America'' and also commonly referred to as ''GSA Bulletin'') is a peer-reviewed scientific journal that has been published by the Geological Society of America since 1890. Its first editor was William John McGee.Eckel, Edwin, 1982, GSA Memoir 155, The Geological Society of America — Life History of a Learned Society, p. 79., . According to the ''Journal Citation Reports ''Journal Citation Reports'' (''JCR'') is an annual publication by Clarivate. It has been integrated with the Web of Science and is accessed from the Web of Science Core Collection. It provides information about academic journals in the natur ...'', the journal has a 2016 impact factor of 4.212. See also * List of scientific journals in earth and atmospheric sciences References External links * Geological Society of America English-language journals Geology journals Bimonthly journals [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Lee Armstrong
Richard Lee Armstrong (August 4, 1937 – August 9, 1991) was an American-Canadian scientist who was an expert in the fields of radiogenic isotope geochemistry and geochronology, geochemical evolution of the earth, geology of the American Cordillera, and large-magnitude crustal extension. He published over 170 scientific papers. Education Armstrong was born in Seattle, Washington. In 1955, he moved to New Haven, Connecticut, to attend Yale University. He obtained his BSc in 1959 and a PhD in 1964. He stayed at Yale as assistant and associate professor in the geology department until 1973. While he was a Yale professor, he took two leaves, the first in 1963–1964 on a National Science Foundation Postdoctoral Fellowship at the University of Berne, and in 1968–1969 as a Morse and Guggenheim Fellow at the Australian National University and California Institute of Technology. Career In 1973, Armstrong moved to Vancouver, British Columbia, Canada to be an associate profe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Member (geology)
A stratigraphic unit is a volume of rock of identifiable origin and relative age range that is defined by the distinctive and dominant, easily mapped and recognizable petrographic, lithologic or paleontologic features ( facies) that characterize it. Units must be ''mappable'' and ''distinct'' from one another, but the contact need not be particularly distinct. For instance, a unit may be defined by terms such as "when the sandstone component exceeds 75%". Lithostratigraphic units Sequences of sedimentary and volcanic rocks are subdivided on the basis of their shared or associated lithology. Formally identified lithostratigraphic units are structured in a hierarchy of lithostratigraphic rank, higher rank units generally comprising two or more units of lower rank. Going from smaller to larger in rank, the main lithostratigraphic ranks are bed, member, formation, group and supergroup. Formal names of lithostratigraphic units are assigned by geological surveys. Units of form ... [...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] |
Tencho Glacier
Tencho Glacier is a mountain glacier in northwestern British Columbia, Canada. It is located inside Mount Edziza Provincial Park on the Tahltan Highland, an upland area of the Stikine Plateau. Tencho Glacier is the source of several small streams that flow from the Mount Edziza volcanic complex. Etymology The name of the glacier was suggested by the Geological Survey of Canada on November 15, 1979, and eventually became official on November 24, 1980. ''Tencho'' is derived from the Tahltan words ''ten'' and ''cho'', which mean ''ice'' and ''big'' or ''great'' respectively. This glacier is so-named because it is the largest glacier of the Mount Edziza volcanic complex. Geography Tencho Glacier originates from Ice Peak and Tennena Cone on the southern flank of Mount Edziza. Its southern terminus is surrounded by Kaia Bluff in the southeast, Coffee Crater in the south and Cocoa Crater in the southwest. Unnamed tributaries of Taweh Creek originate from the southwestern side of Tenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comenditic
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite. Phenocrysts are sodic sanidine with minor albite and bipyramidal quartz. Iddings, Joseph Paxson, 1913, ''Igneous rocks: composition, texture and classification'', v. 2, pp. 94-96 The blue colour is caused by very small crystals of riebeckite or arfvedsonite. The 1903 eruption of Baekdu Mountain, Changbaishan volcano in northeast China erupted comendite pumice. Comendite derives its name from the area of Le Commende on San Pietro Island in Italy, where the rock type is found.Cioni, R. and Funedda, A., (2005) ''Structural geology of crystal-rich, silicic lava flows: A case study from San Pietro Island (Sardinia, Italy)'' in Manga, M. and Ventura, G. (editors) (2005) ''Kinematics and Dynamics of Lava Flows'', Geological Society of America Special Paper 396, pages 1 to 14. Comendite also occurs in the Glass House Mountains of southeast Queensland, Australia, as well as in Sardinia, Corsica, Ascension Is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
