نتایج جستجو برای: schist

تعداد نتایج: 610  

Journal: :International Geology Review 2021

Massive, boudinaged, rose-coloured layers up to one metre in thickness composed of 60–80 vol% spessartine-rich garnet and 15–40 quartz occur high-pressure, garnet-mica schist on Margarita I...

ملک‌زاده شفارودی, آزاده, مظاهری , سید احمد , کریم‌پور, محمد‌حسن ,

Rock unites which are exposed in Tak-I mine area are: Taknar formation (Ordovician), Mid-late Paleozoic and younger intrusive rocks. Taknar formation consists of sericite schist, chlorite schist, chlorite-sericite schist and some meta-diabase- gabbro-diorite. Taknar Polymetal (Cu-Zn-Au-Ag-Pb) Massive sulfide deposit formed at certain horizon of Taknar formation. Three style of mineralization ar...

Journal: :Journal of African Earth Sciences 2021

Talc schist deposits are reported in central Cameroon region, and different alteration zones were determined depending on differences related to the texture color of host rock. For purpose determining mineralogical physicochemical characteristics talc schist, a total 45 samples from sites studied collected analyzed using an array physico-chemical methods. mainly composed variable amount associa...

2007
Robert L. King Gray E. Bebout Marty Grove Takuya Moriguti Eizo Nakamura

The B and Pb isotope systems are widely applied tracers of recycling processes occurring during subduction. Studies examining these complementary systems as a pair enjoy considerable success, where B primarily records the thermal and fluid evolution of the subducting slab, whereas the tripartite Pb system constrains the source of subducted material returned to volcanic arcs. However, interpreta...

1997
Seppo Elo

An introduction to the Bouguer anomaly map of Finland is presented. Anomaly sources from surface to upper mantle are discussed both qualitatively and quantitatively. Related density variations are reviewed. The article is based on gravity data from the Finnish Geodetic Institute supplemented by petrophysical and gravity data from the Geological Survey of Finland. The Finnish Geodetic Institute ...

2006
Fang-Zhen Teng William F. McDonough Roberta L. Rudnick Richard J. Walker

Lithium concentrations and isotopic compositions in the country rocks (amphibolites and schists) of the Tin Mountain pegmatite show systematic changes with distance to the contact. Both Li and δLi decrease dramatically along a ∼10m traverse from the pegmatite into amphibolite, with Li concentration decreasing from 471 to 68ppm and δLi decreasing from +7.6 to −19.9. Rubidium and Cs also decrease...

The stress configuration and tectonic analysis of the Pan – African orogeny is drawn from the Igarra schist belt, southwestern Nigeria. The analysis of conjugate shear fractures of the schist belt indicates that two distinct compressive events (NE – SW and E – W) occurred in this Pan – African mobile zone. The palaeostress systems reveal a clockwise rotation of compressional axis from D1 (NE – ...

Moeinzadeh, , Bahrambygi, , Rahimisadegh, ,

The Anjir Khajeh area is located in the southern part of Sanandaj-Sirjan metamorphic belt in northwest of Golgohar iron mine. The rock units of the region include metabasites, metasediments, igneous and sedimentary rocks. Metasedimentary rocks containing mica-schist, garnet schist, and garnet staurolite schist, having metamorphosed into greenschist facies and amphibolite facies. Garnet mineral ...

Journal: :زمین شناسی اقتصادی 0
احمد احمدی خلجی زهرا طهماسبی

introduction the area of this study is located near hamadan within the sanandaj - sirjan tectonic zone. in the hamadan area, consisting mainly of mesozoic plutonic and metamorphic rocks, aplites and pegmatites locally contain garnets.(baharifar et al., 2004, amidi and majidi, 1977; torkian, 1995. garnet-bearing schists and hornfelses in the area are products of regional metamorphism shown by sl...

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