Results 31 to 40 of about 3,855 (216)

Facial accessory of high-titanium magnezium-ferruginous micas as one of evaluation criteria of metamorphic and magmatic rocks rare-metall specialization

Литосфера, 2015
Type-chemical features of high-titanium magnezium-ferruginous micas of granulites, mafite-ultramafites, alkaline rocks, and carbonatites are considered.
A. I. Belkovsky
doaj   +2 more sources

Geology and mineralogy of gemming terrains of Sri Lanka [PDF]

Bulletin of the Geological Society of Finland, 1985
Gemming in Sri Lanka is carried out in river valleys and on hill slopes underlain by high grade Precambrian metasedimentary rock suites. The principal gem mineral, corundum, is mined from assemblages rich in garnet, spinel, topaz, tourmaline and zircon ...
K. Dahanayake, A.P. Ranasinghe
doaj   +1 more source

Inhomogeneities of the earth’s crust of the Aldan-Stanovoy shield along the 3-DV profile (Eastern Siberia, Russia

Геофизический журнал, 2021
Profile 3-DV (Skovorodino-Tommot) crosses in the sublatitudinal direction the Stanovoy and Aldan megablocks of the Aldan-Stanovoy shield. As the basic elements of the Earth’s crust section along the profile 3-DV, a technique was adopted for identifying ...
V. V. Stogny, G. A. Stogny
doaj   +1 more source

A Reassessment of Petrochemistry of ~1.2 Ga Tonalitic Rocks of the Northern Tugela Terrane, Natal Metamorphic Belt, South Africa: Further Constraints on the Evolution of This Belt

Geological Journal, EarlyView.
Our petrochemical studies on ~1.2 Ga granitoids of the Natal Metamorphic Belt, South Africa, do not suggest any property similar to Phanerozoic‐style subduction‐related granitoids. Plot of Kotongweni Tonalite in Y versus Sr diagram (after Moyen 2011), note that most samples have Sr/Y < 50.
Palesa Leuta, Saumitra Misra, Thembiso O. Basupi   +2 more
wiley   +1 more source

Low Water Content of the Lower Continental Crust Induced by Decompression Melting: Evidence From the Weichang Granulite Xenoliths in the Northern North China Craton

Geochemistry, Geophysics, Geosystems
The water content of granulite xenoliths from the Cenozoic Weichang basalts in the northern North China Craton (NCC) is investigated to constrain the nature and evolution of the lower crust.
Yuanyuan Liu, Dongya Zou, Xiaoyan Gu, Yantao Hao, Hongfu Zhang, Shenghua Zhou   +5 more
doaj   +1 more source

Petrography and geochemistry of the Pedra Dourada Granulite, southeastern Minas Gerais, Brazil

REM: International Engineering Journal
The Pedra Dourada Granulite (PDG) occurs at the southeastern portion of the Araçuaí Belt, north of the town of Ponte Nova. It comprises bodies up to 45 km2 inserted into amphibolite-facies gneisses of the Mantiqueira Complex. Motivated by the discrepancy
Kassia de Souza Medeiros Marinho, Hanna Jordt-Evangelista, Marcelo de Souza Marinho   +2 more
doaj   +1 more source

Evolution of metamorphic processes in the Neoarchean mafic granulites of the Qingyuan Terrane in northern Liaoning, North China Craton

Dizhi lixue xuebao, 2023
Multiple interpretations exist regarding the tectonic evolution model of the Neoarchean North China Craton, requiring a more in-depth study of metamorphic processes.
CUI Runze, WEI Chunjing
doaj   +1 more source

Heterogeneous Exhumation Mechanisms in Neoproterozoic Collisional Metamorphism: P–T Constraints From Pelotas and Punta del Este Terranes, Southern Brazil and Uruguay

Geological Journal, EarlyView.
Petrography, thermobarometry, and pseudosection modelling reveal peak metamorphic conditions of 3–7.5 kbar and 520°C–800°C in Tonian‐Cryogenian orthogneisses of the Dom Feliciano Belt. Metamorphic field gradients of 27°C/km–39°C/km and variable exhumation mechanisms support correlation of these units as remnants of a Himalayan‐type Piratini Orogeny ...
Thaiane Niederauer‐Santos, Carla Cristine Porcher, Daniel Triboli Vieira, Edinei Koester, Diego Jaldín, Karina Luengo, Luisa Caon   +6 more
wiley   +1 more source

Low–pressure metamorphism of mafic granulites in the Chinese Altay orogen, NW China: P–T path, U–Pb ages and tectonic implications

Solid Earth Sciences, 2020
Mafic granulites occur as massive lenses within host paragneisses at Wuqiagou area in the southern Chinese Altay orogen. They comprise a suite of fine–grained and coarse–grained mafic granulites, both characterized by an assemblage of orthopyroxene ...
Zhao Liu, Laixi Tong, Omar Bartoli, Yi–Gang Xu, Xiaolong Huang, Chao Li   +5 more
doaj   +1 more source

Petrogenesis and Tectonic Setting of Late Mesozoic Felsic Magmatic Rocks in the Wangmushan Mining District, Northern Fujian, South China

Geological Journal, EarlyView.
The rhyolitic ignimbrite and K‐feldspar granite porphyry from the Wangmushan mining district, northern Fujian yield ages of 173.8 ± 0.8 and 102.6 ± 0.4 Ma, respectively. Geochemical data, zircon trace elements, whole‐rock Sr–Nd–Pb isotope data, and zircon Hf isotopic compositions indicate that the rhyolitic ignimbrite originated from partial remelting ...
Wei Shaogang, Hong Wentao, Xiao Fan, Jin Guodong, Shi Hongyang, Ma Zhiwang, Wu Chen, Xue Yujingyang   +7 more
wiley   +1 more source