Timescales of migmatization, melt crystallization, and cooling in a Cordilleran gneiss dome: Valhalla complex, southeastern British Columbia
نویسندگان
چکیده
منابع مشابه
Fast Cooling and Exhumation of the Valhalla Metamorphic Core Complex, Southeastern British Columbia
High-grade, migmatitic paragneisses (820°C, 8 kbar peak conditions) of the Valhalla metamorphic core complex experienced the retrograde net transfer reaction (ReNTR): garnet + melt + K-feldspar = sillimanite + biotite + plagioclase during cooling and crystallization of the melt, resulting in an increase in the Fe/(Fe + Mg) of both garnet and biotite at their margins. Diffusion profiles generate...
متن کاملPetrology and Cooling Rates of the Valhalla Complex, British Columbia, Canada
Rocks from the Valhalla metamorphic core complex, British Columbia, Canada, have experienced granulite Jades metamorphism at conditions of 820±30°C, 8±1 kbar. Peak metamorphism was accompanied by dehydration melting of muscovite, but not biotite, followed by minor back reaction of garnet + K-feldspar + H20sillimanite + biotite+plagio close.' At conditions very near those of the peak, extensive ...
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Various mechanisms have been proposed for the dynamic cause and kinematic development of gneiss domes. They include (1) diapiric fl ow induced by density inversion, (2) buckling under horizontal constriction (i.e., extension perpendicular to compression), (3) coeval orthogonal contraction or superposition of multiple phases of folding in different orientations, (4) instability induced by vertic...
متن کاملIRON RAlVGE DEPOSITS, SOUTHEASTERN BRITISH COLUMBIA
alteration was ohserved along minor subsidiary faults in the northwest and northeast parts of Iron Range Mountain. The main Iron Range deposit consists of the segment of the ault containing the richest iron mineralization and underlies the northern half of the ridge which makes up Iron Range Mountain. This area extends northward onto the Grassy Mountain sheet (82FB). The area of m...
متن کاملOrigin of the Kootenay Lake Metamorphic High, Southeastern British Columbia
A nar row, elon gate re gion of an oma lously high meta mor phic grade runs par al lel to Kootenay Lake, in the cen tral part of the Kootenay Arc, south east ern Brit ish Co lum bia. Meta mor phic grade ranges from the chlorite/bi o tite zones on the flanks to the sillimanite+K-feld spar zone in the cen tre of the high. In this pa per, we pres ent a sum mary of struc tural, meta mor phic and ge...
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ژورنال
عنوان ژورنال: Tectonics
سال: 2008
ISSN: 0278-7407
DOI: 10.1029/2007tc002103