نتایج جستجو برای: quartz schist

تعداد نتایج: 12669  

Journal: :Journal of Petrology 2022

Abstract Garnet–kyanite–staurolite assemblages with large, late porphyroblasts of amphibole form garbenschists in Ordovician volcaniclastic rocks lying immediately south the Pearya terrane on northernmost Ellesmere Island, Canada. The schist, which together carbonate olistoliths makes up Petersen Bay Assemblage (PBA), displays a series parallel isograds that mark an increase metamorphic grade o...

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...

1999
S. C. PATEL C. D. FROST B. R. FROST

Archean supracrustal sequences of pelitic, quartzitic, calcareous and mafic compositions in the central Laramie Mountains, Wyoming, have been affected by two metamorphic events: a 1.78 Ga amphibolitegrade regional metamorphism, and a 1.43 Ga contact metamorphism resulting from the intrusion of the Laramie Anorthosite Complex (LAC). Rb–Sr whole-rock isotopic data from both outside and within the...

Journal: :Spectrochimica Acta Part B: Atomic Spectroscopy 2022

Mineralogical and petrographic studies require analytical methods capable to underline the repartition of major trace elements within geological samples. The EPMA (Electron Probe Micro Analyzer) conventional method used for such investigation, but on restrictive zones, is verge be reached by μLIBS (micro Laser-Induced Breakdown Spectroscopy) μXRF X-Ray Fluorescence) techniques allowing elementa...

Journal: :Geotechnical and Geological Engineering 2021

Several physical parameters and anisotropy related to rock textural arrangements, schistosity weakness planes such as cracks joints affect the P-wave velocity (VP). First, VP of quartz-mica schist a common type widespread metamorphic was compared with jointed homogeneous limestone specimens clarify effect these two different types anisotropies. The results showed that texture is stronger than l...

Journal: :Geological Society of America Bulletin 2022

Abstract The timing of deformation and associated gold mineralization in SE California, USA, is contentious, partly due to the challenges involved with dating ductile deformation. We therefore combine modern geo- thermochronology field microscopic observations show that Cargo Muchacho Mountains preserve evidence northward thrusting a kilometer-scale shear zone during Late Cretaceous Laramide Or...

احمدی, علی, مجددی مقدم, حلیمه,

Metamorphic rocks in SW Arak composed from two groups including regional and contact metamorphism. Regional metamorphic rocks are composed of slate, phyllite and micaschists and locted in green-schist facies and contact metamorphic rocks are composed of spotted schist and hornfels respectively. Mineralogically, these rocks are composed of quartz, chlorite, muscovite, biotite and cordierite. Pet...

احمدی‌خلجی, احمد, سپه‌وند, فرزانه , طهماسبی, زهرا ,

Metamorphic rocks in SW Arak composed from two groups including regional and contact metamorphism. Regional metamorphic rocks are composed of slate, phyllite and micaschists and locted in green-schist facies and contact metamorphic rocks are composed of spotted schist and hornfels respectively. Mineralogically, these rocks are composed of quartz, chlorite, muscovite, biotite and cordierite. Pet...

Bayat, Sima, Didar, Pejvak, Jahangiri, Ahmad, Siahcheshm, Kamal,

The Malayer-Boroujerd-Shazand district (approximately 70 km long) is located in the Sanandaj-Sirjan zone with NW-SE trending, and consist mainly of hornfels, schist, phyllite, migmatite, granite and granodiorite which contain numerous pegmatite and aplitic dykes. Among these rocks, granodiorite, hornfels and schist are main host rocks for quartz, feldspar, muscovite and tourmaline bearing pegma...

Abbasnia, Hosain, Karimpour, Mohammadhasan, Malekzadeh Shafaroudi, Azadeh,

The Damanghor gold mineralization occurrence is located in north of Bardaskan, Khorasan Razavi Province, and Taknar zone.The geology of the area consists of Precambrian green sericite schist and metarhyolite, intruded by diabase. Mineralization in this area is in vein form with N50E stribe and 70NW dip and hosted by schist and metarhyolite with 300 meters length and 2 to 35 meters width. Dissem...

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