نتایج جستجو برای: mafic composition

تعداد نتایج: 261231  

2015
L. M. Jozwiak W. Head

2755. [19] Wieczorek, M. A. et al. (2013) Science 339, 671-675. Figure 1: Locations of floor-fractured craters [2] plotted on a basemap of crustal thickness [19]. Floor-fractured craters are preferentially located in regions of intermediate (20-30 km) crustal thickness. Mare deposits are located primarily on the lunar nearside and in regions of thinner crust. Figure 2: Crater Buch B (17.0°E, 39...

Journal: :Anais da Academia Brasileira de Ciencias 2006
Renato J Leite Valdecir A Janasi Lucelene Martins

The Piedade Granite (approximately 600 Ma) was emplaced shortly after the main phase of granite magmatism in the Agudos Grandes batholith, Apiaí-Guaxupé Terrane, SE Brazil. Its main units are: mafic mineral-rich porphyritic granites forming the border (peraluminous muscovite-biotite granodiorite-monzogranite MBmg unit) and core (metaluminous titanite-bearing biotite monzogranite BmgT unit) and ...

Journal: :زمین شناسی اقتصادی 0
مریم آهنکوب یوشی هیرو آساهارا

introduction there are some theories about the paleotethys event during the paleozoic that have been proposed by geologists (metcalfe, 2006). some scientist offered some pieces of evidence about the northern margin of gondwana (zhu et al., 2010). the paleotethys ocean and hercynian orogenic report first in iran, have been offered from the morrow and misho mountain (eftekharnejad, 1981). misho m...

2006
P. G. Lucey

Introduction: Several types of magnesian highlands rocks occur in the lunar samples including the mafic Mg-suite rocks, magnesian feldpathic granulites, and magnesian anorthosites. Some mafic magnesian rocks are easily accommodated into the magma ocean model, as large variations in Mg/Fe are expected as the magma ocean crystallizes, forming source regions for magnesian melts. The origin of othe...

مؤید, محسن, مجرد, منیر, حسین زاده, قادر,

In the mafic-ultramafic suite of Tazehkand, Kalaybar-NW Iran, of Early-Cenozoic age, pyroxenitic core is surrounded by gabbro and total complex is surrounded by Paleocene volcano clastic of Majid Abad Formation. The pyroxenite is composed chiefly of Cpx+Ol+Ore. The associated gabbro minerals consist of Pl + Cpx + Am + Phl. The pyroxene composition in the two rock types is diopside-rich and rang...

K.R. Praveen P. Pratheesh V. Prasannakumar

Cretaceous mafic dykes in the Moyar Shear Zone (MSZ) area, north Kerala, India, provide signatures to probe into the nature of their source and thereby the evolution of the Mesozoic lithospheric mantle beneath the South Indian Granulite Terrain (SIGT). Bulk of the dykes in northern parts of Kerala is broadly in spatial association with the shear system. Mafic dykes striking NE-SW, NWSE, NNW-SSE...

Journal: :Lithos 2022

Mafic pegmatites have been reported from various geological environments, including ophiolites, layered magmatic intrusions, and volcanic arcs, but their petrogenesis stayed poorly constrained. This study brings new mineralogical geochemical data obtained unzoned zoned gabbroic hosted by the 1.8 Ga mafic-ultramafic Hamn intrusion, Northern Norway, with an aim to improve our understanding of pri...

Journal: :زمین شناسی اقتصادی 0
مریم آهنکوب احمد جهانگیری محسن مؤید

misho intrusions outcrop in the southern part of north tabriz fault, east misho mountains, nw tabriz. filed studies, petrological and geochemical data show that both mafic and felsic rock types occur in the area. mafic rocks include gabbro consisting of plagioclase, clinopyroxene, olivine and opaque minerals and felsic bodies consist of alkali granite with k-feldspar, quartz, plagioclase and a ...

Journal: :Minerals 2021

Pyroxenite and nepheline-pyroxene rocks coexist with dolomite-bearing calcite marbles in Tazheran Massif the area of Lake Baikal, Siberia, Russia. Pyroxenites occur a continuous elongate zone between beerbachites (metamorphosed gabbro dolerites) 5 cm to 20 m fragments among marbles. Pyroxene pyroxenite is rich calcium alumina (5–12 wt% Al2O3) has fassaite composition. The may originate from maf...

2001
Matthew I. Staid Carle M. Pieters

High spatial resolution Clementine images are examined to measure the reflectance properties of small and optically immature mare craters that have sampled discrete compositional units. The spectral properties of these relatively crystalline mare materials are compared to associated mature soils to determine the effects of space weathering on specific basalt types. Space weathering is observed ...

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