نتایج جستجو برای: granodiorite

تعداد نتایج: 508  

2015
Michael Brown

Cutts et al. (2014) combined thermodynamic modeling of compositional change in metamorphic garnet with metamorphic peak and retrograde pressure-temperature (P-T ) data derived from quantitative P-T pseudosections to determine clockwise P-T paths for several samples from the Tjakastad schist belt. The Tjakastad schist belt is located in the central portion of the Stolzburg domain at the southwes...

2003
Marcus Wigand Axel K. Schmitt Robert B. Trumbull Igor M. Villa Rolf Emmermann

The Erongo subvolcanic center in Namibia is the largest composite, bimodal complex in the Mesozoic Etendeka igneous province of Namibia. This study of 40Ar/39Ar and high spatial resolution U^Pb zircon dating demonstrates that emplacement of the various igneous units at Erongo took place within a time span equivalent to or shorter than geochronologically resolvable age differences (ca. 2 Ma), an...

Journal: :زمین شناسی اقتصادی 0
سمیرا زندی فر محمد ولی ولی زاده محمد علی برقی

in the contact metamorphic aureole of the next to the granodiorite intrusive body in the hassan-abaad village of yazd, high frequency garnet in different metamorphic zones is notable, which some contain garnet crystal with obvious zoning. obtained data from core to rim of garnet by sem point analysis, show that garnet crystals belong to grandite series, and sharp variation of al and fe from cen...

Journal: :Communications earth & environment 2023

Abstract The composition and origin of Earth’s earliest continental crust remains enigmatic due to the absence Hadean (>4 Ga) age rocks. Here we address this question by using machine learning examine provenance 4.4–3.3 Ga Jack Hills zircons, which constitute best archive crust. Our results reveal that although some zircons may be derived from trondhjemite-tonalite-granodiorite series rocks,...

2010
M. A. Obeid

The Wadi Hodein area contains a wide variety of late Precambrian igneous and metamorphic rocks, represented by gneisses, serpentinites, metagabbros, metasediments, metavolcanics, metagabbro-diorite, granodiorite and granitoids. The Wadi Hodein metavolcanics (WHV), including G. Khashab and G. El Anbat, represent one of the significant metavolcanic suites in the southern part of the Nubian Shield...

2006
Shiloh Osae Daniel K. Asiedu Bruce Banoeng-Yakubo Christian Koeberl Samuel B. Dampare

The petrography, as well as major and trace element (including rare earth element) compositions of 10 sandstone samples from the Late Proterozoic Buem Structural Unit, southeast Ghana, have been investigated to determine their provenance and tectonic setting. The petrographic analysis has revealed that the sandstones are quartz-rich and were primarily derived from granitic and metamorphic basem...

2017
F Talarico S Sandroni Christopher R. Fielding F. Talarico

Distribution patterns, petrography, whole-rock and mineral chemistry, and shape and fabric data are described for the most representative basement lithologies occurring as clasts (granule to boulder grain-size class) from the 625 m deep CRP-2/2A drillcore. A major change in the distribution pattern of the clast types occurs at c. 310 mbsf, with granitoid-dominated clasts above and mainly doleri...

2012
Lorence G. Collins

The AOC Granite 7-32-89-10 hole, drilled to search for oil in the Precambrian basement below the Alberta bituminous (tar) sands near Fort McMurray, Canada, penetrates layered biotite-hypersthene quartz diorite-gabbro sills that occur between 543 and 2363.3 meters depth. Three episodes of fracturing and cataclasis affected these sills. The first allowed Kand Si-metasomatism to change many parts ...

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