Results 141 to 150 of about 811 (185)

Metasedimentary cordierite-gedrite rocks of Archean age near Yellowknife, Canada

Precambrian Research, 1979
Abstract Archean metasedimentary rocks near Yellowknife comprising metagreywacke and metaargillite, form broad aureoles around granite plutons. Cordierite-gedrite greywackes constitute an important metamorphic horizon within the aureoles. The chemical composition of the cordierite-gedrite greywackes, from Yellowknife compare well with greywackes ...
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Subsolidus segregation of quartz in metamorphic differentiation of metasedimentary rocks

Doklady Earth Sciences, 2017
Thermodynamic modeling of the SiO2–TiO2–Al2O3–Fe2O3–MnO–MgO–CaO–Na2O–K2O–P2O5–H2O (STAFMMCNKPOH) system at 600°C, 5 kbar has been applied to investigate dissolution and re-precipitation of quartz. Comparing silica molality in the STAFMMCNKPOH and SiO2–H2O systems, there is seen to be no effect of mineral assemblage on quartz solubility.
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Geochemistry and sedimentology of Grampian Group metasedimentary rocks, Upper Strathspey

Scottish Journal of Geology, 1989
Synopsis The sedimentological attributes of the metasedimentary rocks of Upper Strathspey are inferred from their major and trace element geochemistry. The rocks of the Glenshirra Succession have high oxidation ratios and are of a lithic nature which suggests shallow water, probably alluvial, environments.
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Geochemistry of metasedimentary rocks of Uwet area, Oban Massif, southeastern Nigeria

Geologische Rundschau, 1986
Metasediments comprising phyllites, schists and gneisses constitute the predominant rock types in Uwet area of the Oban Massif of southeastern Nigeria. These rocks which range from middle greenschist to uppermost amphibolite facies grade are products of Barrovian-type regional metamorphism. They are of Pan-African age (600 ± 100 Ma).
Ekwueme, B. N., Onyeagocha, A. C.
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Metasedimentary, granitoid, and gabbroic rocks from central Stewart Island, New Zealand

New Zealand Journal of Geology and Geophysics, 1997
Abstract A NNE—NE trending strip, 3–8 km wide, extending from the Freshwater valley across Mt Rakeahua, Table Hill, and Mt Allen to the northern end of the Tin Range was mapped at a scale of 1:12 500 to locate and investigate the boundary between the Median Tectonic Zone (MTZ) and Western Province on Stewart Island.
A. H. Allibone, A. J. Tulloch
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GRAPHITIZATION OF METASEDIMENTARY ROCKS IN THE WESTERN KONYA

2015
The Paleozoic-Mesozoic metasedimentary rocks in the study area are metacarbonate, metachert, metapelite, metasandstone and metaconglomerate. Graphite layers are 1cm to 2m thick, extend laterally for tens of meters and are intercalated with metasedimentary rocks.
KURT, Hüseyin, EREN, Yaşar
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CO2-Brine immiscibility at high temperatures, evidence from calcareous metasedimentary rocks

Contributions to Mineralogy and Petrology, 1982
Study of fluid inclusions in quartz segregations and in the rock matrix of a calcareous psammite and a carbonate schist suggests that brines containing 23–24 weight percent salt (NaCl equivalent) are immiscible with CO2 at the metamorphic conditions of approximately 600° and 6.5 Kb. The presence of a high temperature solvus between saline brine and CO2
Crawford, María Luisa, Thompson, Peter H., Sisson, Virginia B.   +2 more
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Rb-Sr Dating of Middle Precambrian Metasedimentary Rocks of Minnesota

Geological Society of America Bulletin, 1966
Rb-Sr dating of middle Precambrian metasedimentary rocks of central and northern Minnesota indicates a loss of radiogenic strontium during regional metamorphism. Samples of the Mahnomen Formation yield two distinct isochrons of 1.75 and 1.46 b.y. Samples dated at 1.46 b.y.
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Uranium in early Proterozoic phosphate-rich metasedimentary rocks of east-central Minnesota

Economic Geology, 1986
Exploration for unconformity-type uranium deposits in the late 1970s in east-central Minnesota led to the discovery of several uranium-bearing phosphorite occurrences in rocks of early Proterozoic age. In this report the authors use the term phosphorite for a rock or specimen that contains substantial sedimentary apatite (Altschuler et al., 1958).
Peter L. McSwiggen, Glen B. Morey, Paul W. Weiblen   +2 more
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MICROSTRUCTURES AND COMPOSITION OF ANATECTIC MELT INCLUSIONS IN METASEDIMENTARY ROCKS

2011
Melt inclusions (MI) investigation represents a widely used approach to gain information on a number of igneous processes on the Earth system. The recent finding of crystallized and glassy MI in high-grade, partially melted metapelites and metagraywackes opened up the possibility to investigate also anatectic processes with the same method. The present
Ferrero S, Bartoli O, Cesare B, Salvioli Mariani E, AcostaVigil A, Cavallo A, Groppo C, Battiston S   +7 more
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