Leucogranite - Wikipedia
WEBLeucogranite is a light-colored, granitic, igneous rock containing almost no dark minerals. Leucogranites have been reported from a variety of orogenies involving continental collisions. Examples include the Black Hills (Trans-Hudson orogeny of Proterozoic age), [1] the Blue Ridge basement complex (Grenville orogeny of Proterozoic age), [2] the ...
Alaskite: Mineral information, data and localities. - mindat.org
WEBA light coloured alkali-feldspar-granite consisting almost entirely of quartz and alkali feldspar and with M' colour index less than 10. In the United States, a commonly used term for a granitic rock containing few, if any, dark minerals.
Mechanisms of Formation of Alaskite, Aplite, and Pegmatite in a …
WEBMechanisms of Formation of Alaskite, Aplite, and Pegmatite in a Dike Swarm, Yosemite National Park, California. Examination of the relationships between textural variations and structural features in a complex, leucocratic dike swarm that is enclosed in the Half Dome quartz monzonite of the Sierra Nevada batholith led to the conclusion that ...
Blue Ridge Rocks: the microscopic view - The William & Mary Blogs
WEBDec 14, 2011 · A number of older geologic studies describe an alaskite, a felsic igneous rock composed primarily of K-feldspar (K for the element potassium) and quartz, intruding the greenstones of the Catoctin Formation. Alaskite, as a rock name, is anachronistic and modern petrologists refer to these rocks as alkali-granites.
Alkali feldspar granite – Geology is the Way
WEBIf M < 10% the rock can be named alaskite (i.e. a leucocratic variety of alkali feldspar granite). Some alkali feldspar granites may be so rich in alkaline elements (Na and K) to contain Na-amphibole (richterite) and/or Na-pyroxene (aegirine): in this case, they should be classified as peralkaline granites .
WEBAlaskite is an extremely light colored variety of granite composed primarily of three minerals. Over one-half is white feldspar of two types, plagioclase and microcline; the rest is light gray quartz and silvery muscovite mica. Some …
Identifying Granitoids and Other Granite Rocks - ThoughtCo
WEBAug 13, 2018 · Granites may be especially light-colored and nearly pure feldspar-plus-quartz—that is, they may be very highly felsic. That qualifies them for the prefix "leuco," meaning light-colored. Leucogranites may also be given the special name aplite, and leuco alkali feldspar granite is called alaskite.
Precambrian Granville alaskite bodies as ash-flow tuffs, northwest ...
WEBThe Hyde School and Reservoir Hill alaskite bodies in the Grenville part of the northwest Adirondacks have a mineral, textural, and chemical zonation that strongly suggests relict stratigraphy.
GEOLOGY - U.S. National Park Service
WEBMar 28, 2006 · Light-tan to pink fine- to medium-grained bodies of alaskite are found on Hagan Mountain north of Berdeen Lake and on the north side of Bear Creek (fig. 15A). The alaskite is composed of 30-40 percent perthite, 20 …
Alaskite Definition & Meaning - Merriam-Webster
WEBThe meaning of ALASKITE is a leucocratic granite of medium or fine grain composed chiefly of quartz and alkali feldspars.
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