نتایج جستجو برای: metamorphic rock

تعداد نتایج: 42928  

2006
J. R. Morrow

Introduction: Individual grains and small lithic clasts in thin-sectioned suevitic breccia samples from the International Continental Scientific Drilling Program (ICDP) Bosumtwi impact crater drillcore LB07A were examined petrographically to evaluate the occurrence , abundance, and characteristics of unshocked and shock-metamorphosed quartz. The analyzed samples were taken across a ~42-m-long (...

2006
Daniel BOAMAH Christian KOEBERL

available online at http://meteoritics.org 1761 © The Meteoritical Society, 2006. Printed in USA. Petrographic studies of “fallout” suevite from outside the Bosumtwi impact structure, Ghana Daniel BOAMAH† and Christian KOEBERL* Department of Geological Sciences, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria †Present address: Geological Survey Department, P.O. Box M80, Accra, Gh...

Journal: :Contributions to Mineralogy and Petrology 2021

Abstract The major-element chemical composition of garnet provides valuable petrogenetic information, particularly in metamorphic rocks. When facing detrital garnet, information about the bulk-rock and mineral paragenesis initial garnet-bearing host-rock is absent. This prevents application thermo-barometric techniques calls for quantitative empirical approaches. Here we present a discriminatio...

Journal: :Theor. Comput. Sci. 2015
Mila Dalla Preda Roberto Giacobazzi Saumya K. Debray

a r t i c l e i n f o a b s t r a c t Abstract interpretation Program semantics Metamorphic malware detection Self-modifying programs Metamorphic code includes self-modifying semantics-preserving transformations to exploit code diversification. The impact of metamorphism is growing in security and code protection technologies, both for preventing malicious host attacks, e.g., in software divers...

2008
A. A. SEPAHI

The study area is a part of the Sanandaj-Sirjan metamorphic belt comprising lowto high-grade regional and contact metamorphic rocks that are intruded by various plutonic bodies. Garnet crystals are abundant in pelitic schists, amphibole schists, migmatites, hornfelses and aplites. They are mostly almandinerich (XAlm>60) pyralspite garnets and show dodecahedron, trapezohedron and mixed (dodecahe...

2002
K. Mezger A. N. Halliday

Garnet-whole rock and garnet-mineral isochrons were determined on granulite facies gneisses and amphibolites from the Archean Pikwitonei Granulite Domain of the Superior Province, and the Proterozoic Central Gneiss Belt and Adirondack Highlands of the Grenville orogen. The Sm-Nd ages obtained from Archean garnets 0.1-0.5 cm in length are 30-110 Ma younger than the U-Pb ages obtained on the same...

2018
Michael P Russell Victoria K Gibbs Emily Duwan

Sea urchins are dominant members of rocky temperate reefs around the world. They often occur in cavities within the rock, and fit so tightly, it is natural to assume they sculpted these "pits." However, there are no experimental data demonstrating they bore pits. If they do, what are the rates and consequences of bioerosion to nearshore systems? We sampled purple sea urchins, Strongylocentrotus...

2006

The effectiveness of lichens in degrading their rock substrates, leading to the first stages in the formation of soil, has long been discussed and opinions have varied widely (Jones, 1988; Syers & lskandar, 1973). Nevertheless, it is generally recognized that lichen encrusted rocks provide an ideal environment for studying the biological weathering of minerals since, unlike the situation in soi...

آهنگری, معصومه ,

Rare earth and trace element concentrations of mineral assemblages including amphibole, plagioclase, epidote group minerals (zoisite and clinozoisite) and relict clinopyroxenes from parental rock of epidote amphibolite from north of Urumia were obtained in situ by LA-ICP-MS analysis. The obtained data were used to study distribution of trace elements among metamorphic phases and relict clinopyr...

Journal: :Buildings 2022

Low-grade metamorphic rock (LMR) is a kind of stone that widely distributed in China. The alkali activity strictly prevents its application conventional concrete. This paper evaluates the possibility using LMR aggregate cement-stabilized pavement base (CSPB). compressive strength CSPB prepared with and limestone aggregates at various curing conditions was measured. Expansion rates were determin...

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