نتایج جستجو برای: alkali granite

تعداد نتایج: 20054  

Journal: :Minerals 2023

The petrogenesis of aluminous A-type granites is a contentious subject. Here, we focused on the North Kudi pluton in Western Kunlun orogen to investigate origin and magmatic processes responsible for generating granites. Samples from are metaluminous weakly peraluminous. K-feldspar granite samples characterized by high alkali Cl contents, HFSE concentrations FeO/MgO, low F content, negative Ba,...

Journal: :Lithos 2021

We describe the Jebel Aja igneous intrusion (JAII), which sits at farthest northeastern edge of exposed Arabian Shield in Saudi Arabia. The JAII consists late Neoproterozoic post-collisional A-type granites, and was emplaced during tectonic extension. It is a composite pluton consisting granitic core (monzogranite, syenogranite alkali feldspar granite) surrounded by later phase alkaline peralka...

Journal: :Minerals 2022

Different rock types (syenogranite, alkali feldspar granite and quartz syenite intruded by microgranite dikes veins) were investigated in the Nikeiba region Egypt. The main components of studied intrusive rocks, comprised granites syenite, are plagioclase, amphibole, biotite, K-feldspar different proportions. Ground gamma ray measurements show that syenogranite, have highest radioactivity (K, e...

2002
D. R. Marchant A. R. Lewis

A thin glacial diamicton, informally termed Granite drift, occupies the floor of central Beacon Valley in southern Victoria Land, Antarctica. This drift is ,1.0 m thick and rests with sharp planar contacts on stagnant glacier ice reportedly of Miocene age, older than 8.1 Ma. The age of the ice is based on 40Ar/39Ar analyses of presumed in situ ash-fall deposits that occur within Granite drift. ...

Journal: :Frontiers in Earth Science 2023

Lying along the south of Mongol–Okhotsk Suture Belt (MOSB) in Horqin Right Middle Banner Inner Mongolia, Chuhuertu granite is exposed Duerji tectonic melange. Based on systematic field geological characteristics, petrology, geochemistry, and zircon U-Pb chronology, we determined petrogenesis pluton setting, provide evidence for dominant factors magmatism study area. LA-ICP-MS dating showed an a...

Journal: :Applied occupational and environmental hygiene 1999
N J Simcox D Lofgren J Leons J Camp

Occupational exposure to crystalline silica has received renewed attention. The National Conference to Eliminate Silicosis in March 1997, was extensive. The conference included workshops that covered silica exposures and the risks in construction, the mining industry, quarries, and foundries.(1) The Occupational Safety and Health Administration (OSHA) launched a special emphasis program in May ...

1999
T. MARK HARRISON MARTY GROVE KEVIN D. McKEEGAN C. D. COATH OSCAR M. LOVERA PATRICK LE FORT

decompression to achieve the same result appear to require extreme The Manaslu granite is the most studied of the dozen or so plutons conditions not permitted by available geological constraints. that make up the High Himalayan leucogranite belt. The inferred relationship of the Manaslu granite with important Himalayan tectonic structures has inspired repeated attempts to determine its crystall...

Journal: :Science 1982
R V Gentry T J Sworski H S McKown D H Smith R E Eby W H Christie

An innovative ultrasensitive technique was used for lead isotopic analysis of individual zircons extracted from granite core samples at depths of 960, 2170, 2900, 3930, and 4310 meters. The results show that lead, a relatively mobile element compared to the nuclear waste-related actinides uranium and thorium, has been highly retained at elevated temperatures (105 degrees to 313 degrees C) under...

2013
Wu-Bin Yang He-Cai Niu Wei-Dong Sun Qiang Shan Yong-Fei Zheng Ning-Bo Li Cong-Ying Li Nicholas T. Arndt Xing Xu Yu-Hang Jiang Xue-Yuan Yu

Cretaceous represents one of the hottest greenhouse periods in the Earth's history, but some recent studies suggest that small ice caps might be present in non-polar regions during certain periods in the Early Cretaceous. Here we report extremely negative δ(18)O values of -18.12‰ to -13.19‰ for early Aptian hydrothermal zircon from an A-type granite at Baerzhe in northeastern China. Given that ...

The granite stone is the most widely used in the construction and granite slurry is generated through cutting and polishing of the stone. Granite slurry is waste material consisting of very fine powder and creats disposal and environmental problems in worldwide today. Disposal of granite waste leads to health hazards like respiratory and allergy problems to the people around. It also causes the...

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