Granitic Gneiss

2019 ◽  
pp. 228-228
Keyword(s):  
Granitic Gneiss

scholarly journals Provenance and tectonic significance of the Zhongwunongshan Group from the Zhongwunongshan Structural Belt in China: insights from zircon geochronology

2020 ◽  
Vol 12 (1) ◽  
pp. 25-43
Author(s):  
Yuan Peng ◽  
Yongsheng Zhang ◽  
Eenyuan Xing ◽  
Linlin Wang
Keyword(s):  
Detrital Zircon ◽  
Sedimentary Basin ◽  
Early Paleozoic ◽  
Granitic Gneiss ◽  
Metamorphic Belt ◽  
Early Devonian ◽  
Tectonic Environment ◽  
Tectonic Significance ◽  
North Qaidam ◽  
Back Arc

AbstractThe Zhongwunongshan Structural Belt (ZWSB) locates between the Olongbruk Microblock of North Qaidam and the South Qilian Block in China, and it has important implication for understanding the tectonic significance of North Qaidam. Nowadays, there are few discussion on the Caledonian tectonothermal events of the Zhongwunongshan Structural Belt, and there exist different opinions on provenance and tectonic environment of the Zhongwunongshan Group in the ZWSB and its adjacent North Qaidam. In this study, a comprehensive analysis of the detrital zircon geochronological research was carried out on the Zhongwunongshan Group. The detrital zircon U-Pb dating results showed two major populations. The first was Neoproterozoic (966-725 Ma) with a ∈Hf(t) = −15.9 to 9.5, and the other was late Early Paleozoic (460-434Ma) with a ∈Hf(t) = −9.6 to −3.1. In combination with previous research, the dominated provenances were found to be the Neoproterozoic granitic gneiss of the Yuqia-Shaliuhe HP-UHP metamorphic belt and the late Early Paleozoic granite of the Tanjianshan ophiolite-volcanic arc belt in North Qaidam. The Zhongwunongshan Group was deposited in the back-arc sedimentary basin related to the Caledonian collisional orogeny during Middle Silurian-Early Devonian (434-407.9 Ma).

Geotechnical characteristics of weathered granitic gneiss with geo-hazards investigation of pit excavation in Guangzhou, China

2016 ◽  
Vol 76 (2) ◽  
pp. 681-694 ◽  
Author(s):  
Mu Chen ◽  
Shui-Long Shen ◽  
Huai-Na Wu ◽  
Zhi-Feng Wang ◽  
Suksun Horpibulsuk
Keyword(s):  
Granitic Gneiss ◽  
Geotechnical Characteristics

scholarly journals Geochemical Classification and Geotectonic Setting of Granitic Gneisses from Southeastern Margin of Western Nigeria Basement

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Mohammed Olatoye Adepoju ◽  
Yinusa Ayodele Asiwaju-Bello
Keyword(s):  
Inductively Coupled Plasma ◽  
Tectonic Setting ◽  
Calc Alkaline ◽  
Granitic Gneiss ◽  
Basement Complex ◽  
Southwestern Nigeria ◽  
Inductively Coupled ◽  
Continental Arc ◽  
Southeastern Margin ◽  
Geochemical Classification

Chemical whole-rock major oxides and some trace element analyses were done on granitic gneiss rocks located on the southeastern margin of western Nigeria Basement Complex, exposed in parts of Dagbala-Atte District, southwestern Nigeria. This was meant to classify the rocks and to understand the tectonic setting in order to evaluate their crustal evolution. The chemical analyses were done using inductively-coupled plasma mass spectrometer. From the results obtained, these rocks classified into calc-alkaline to shoshonite series with metaluminous to peraluminous varieties, they are I-type granitoids of feroan composition. The granitic gneisses formed from metamorphism of granite and granodiorite. Tectonically, most of the rock samples plotted in the field of island arc, continental arc and continental-collisional granitoids, which indicated that the protolith granite and granodiorite are orogenic and are arc related inferring arc tectonic setting.

scholarly journals Asplenium X kentuckiense on Granitic Gneiss in Georgia

1966 ◽  
Vol 56 (4) ◽  
pp. 145 ◽  
Author(s):  
Wilbur H. Duncan
Keyword(s):  
Granitic Gneiss

Temperature effects on strength and deformation behaviour of rocks in Southern Ontario

1982 ◽  
Vol 19 (3) ◽  
pp. 307-319 ◽  
Author(s):  
Raymond S. C. Wai ◽  
K. Y. Lo
Keyword(s):  
Deformation Behaviour ◽  
Deformation Modulus ◽  
Temperature History ◽  
Granitic Gneiss ◽  
Experimental Procedure ◽  
Deformation Properties ◽  
History Of ◽  
Strength And Deformation ◽  
Effects Of Temperature ◽  
Increasing Temperature

A laboratory program to study the effects of temperature up to 350 °C on the strength and deformation properties of rocks was carried out. Particular attention was paid to the experimental procedure to avoid premature thermal cracking of the specimens. It was shown that the thermal–mechanical behaviour varies with the rock type. For granitic gneiss, the deformation modulus increases slightly with temperature up to 120 °C, then decreases at a rate of about 25% per 100 °C. Poisson's ratio generally decreases with increasing temperature up to 250 °C. The uniaxial compressive strength of granitic gneiss decreases with increasing temperature at a rate of the order of 30 MPa per 100 °C. The deformation properties of the granitic gneiss are also dependent on the temperature history of the specimen.In contrast, both the deformation and strength behaviour of the limestone appear to be insensitive to temperature change.

Charles Darwin on the Origin and Diversity of Igneous Rocks

1996 ◽  
Vol 15 (1) ◽  
pp. 49-67 ◽  
Author(s):  
Paul Pearson
Keyword(s):  
Charles Darwin ◽  
Modern Science ◽  
Igneous Rocks ◽  
Melting Points ◽  
Granitic Gneiss ◽  
Igneous Petrology ◽  
Physical Separation ◽  
Basaltic Melts ◽  
Sinking And Floating ◽  
Beagle Voyage

Charles Darwin provided one of the first detailed explanations for the diversity of igneous rocks. Building on many observations made during the Beagle voyage, Darwin hypothesized that density differences among crystals within a mass of partially molten rock would result in their physical separation by sinking and floating. Such a process, he proposed, could be responsible for the separation of compositionally distinct lavas from a single source. This idea, in modified form, lies at the heart of the modern science of igneous petrology. Darwin also speculated that partial melting of rocks in the deeper regions of the Earth's crust could produce basaltic melts. However, due to his lack of knowledge of the melting points of the silicate minerals, and his misinterpretation of a puzzling field locality at Bahia in Brazil, he wrongly believed granitic gneiss to be the progenitor of these basalts. Despite this error, Darwin's igneous speculations show a characteristic blend of detailed observation and broader theorizing. Most interesting of all, striking analogies can be found between Darwin's igneous work and his theory of natural selection, which he developed at about the same time.

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