Results 21 to 30 of about 759 (173)
The Shahewan rapakivi-textured granite-quartz monzonite pluton, Qinling orogen, central China: Mineral composition and petrogenetic significance [PDF]
Bulletin of the Geological Society of Finland, 2002 The Mesozoic Shahewan pluton consists of four texturally different types of biotite-hornblende quartz monzonite. In the porphyritic types alkali feldspar occurs as euhedral or ovoidal megacrysts that are often mantled by one or more plagioclase shells ...
X. Wang, T. Wang, I. Haapala, X. Lu
doaj +1 more source
Earth Surface Processes and Landforms, Volume 48, Issue 10, Page 1956-1968, August 2023., 2023 In this paper, we link natural fractures with outcrop morphologies and apply the findings in understanding the glacial erosion signatures in crystalline rocks. Abstract This paper addresses the effect of fractures within crystalline bedrock on glacial erosion processes in fast flowing hard bed glacier environments. In particular, we examine (i) whether
Pietari Skyttä +7 more
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Journal of Geophysical Research: Solid Earth, Volume 128, Issue 4, April 2023., 2023 Abstract We analyze envelopes of 233 and 22 ML0.0 to ML1.8 earthquakes induced by two geothermal stimulations in the Helsinki, Finland, metropolitan area. We separate source spectra and site terms and determine intrinsic attenuation and the scattering strength of shear waves in the 3–200 Hz frequency range using radiative transfer based synthetic ...
Tom Eulenfeld +3 more
wiley +1 more source
Secular Evolution of Continents and the Earth System
Reviews of Geophysics, Volume 60, Issue 4, December 2022., 2022 Abstract Understanding of secular evolution of the Earth system is based largely on the rock and mineral archive preserved in the continental lithosphere. Based on the frequency and range of accessible data preserved in this record, we divide the secular evolution into seven phases: (a) “Proto‐Earth” (ca. 4.57–4.45 Ga); (b) “Primordial Earth” (ca. 4.45–
Peter A. Cawood +6 more
wiley +1 more source
Review on geology and mineralization of North Korea (I: Precambrian)
Resource Geology, Volume 71, Issue 4, Page 492-513, October 2021., 2021 The Precambrian geotectonic provinces of North Korea contain continental cores and massifs, active continental margins, and rift zones. The Precambrian strata between the eastern North China Craton (NCC) and North Korea are newly correlated considering rearranged stratigraphy in this review.
Bum Han Lee +3 more
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Terra Nova, Volume 33, Issue 5, Page 502-510, October 2021., 2021 Abstract Fault‐ and fracture‐hosted multi‐stage mineral assemblages that formed by fracture reactivation and fluid migration, constitute archives of the tectonic evolution of Precambrian cratons. Complex intergrowth patterns of these mineral records often hinder absolute dating of mineralization events for geological models.
Mikael Tillberg +5 more
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The Mullnäset rapakivi granite, its chemical and mineralogical composition including a comparison with the Sörvik granite, west central Sweden. [PDF]
, 2016 This contribution presents complimentary mineralogical and whole-rock chemical data for the Mullnäset rapakivi massif. Three rock types occur: gabbro, syenite with associated granite and “normal” rapakivi granite, here denoted rapakivi-textured granite ...
Lindh, Anders
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Plagioclase-mantled K-feldspar in the Carboniferous porphyritic microgranite of Altenberg-Frauenstein, Eastern Erzgebirge / Krušné Hory [PDF]
Bulletin of the Geological Society of Finland, 2002 The Upper Carboniferous porphyritic microgranite of Altenberg-Frauenstein, formerly known as Granitporphyr (Dalmer 1896) and here abbreviated as GP, forms a 36 km long and up to 18 km wide complex of ring dykes related to the Teplice-Altenberg caldera in
A. Müller, R. Seltmann
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Crustal development in relation to granitic magmatism in regard to D/H partition between coexisting hornblende and biotite in the Svecofennian belt [PDF]
Bulletin of the Geological Society of Finland, 1993 Tie-lines in the σD-XFe diagram of hornblende and biotite in Japanese island arc granites give commonly a similar slope to that derived from the equation of Suzuoki-Epstein's experimental work (1976).
Y. Kuroda +5 more
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The rapakivi granite plutons of Bodom and Obbnäs, southern Finland: petrography and geochemistry [PDF]
Bulletin of the Geological Society of Finland, 1999 The Obbnäs and Bodom granite plutons of southernmost Finland show the typical petrographic and geochemical features of the Proterozoic rapakivi granites in Finland and elsewhere: they cut sharply across the 1900 Ma Svecofennian metamorphic bedrock and ...
P. Kosunen
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