Results 51 to 60 of about 31,446 (282)

Cryogenian Glacial Erosion and Tectonics as Agents of Crustal Recycling

open access: yesTerra Nova, EarlyView.
ABSTRACT Zircon preserves evidence of recycling processes that link surface environments to the mantle. Combined δ18O‐εHf in zircon fingerprints magmatic sources and tracks how crustal material is reworked over time. We apply statistical analyses to a global compilation that apparently resolves shifts in zircon U–Pb, δ18O, and Lu‐Hf data spanning the ...
M. Seraine   +9 more
wiley   +1 more source

Petrogenesis of the Kanker Granites From the Bastar Craton: Implications for Crustal Growth and Evolution During the Archean-Proterozoic Transition

open access: yesFrontiers in Earth Science, 2020
Archean-Proterozoic boundary represents a significant transitional phase in the Earth's history. Bastar Craton is one of the major Archean cratons in the Indian subcontinent with voluminous granites, supracrustal rocks, and tectonic belts.
Ajay Dev Asokan   +4 more
doaj   +1 more source

Criteries and prospects of diamonds of the Vitebsk granulite massif

open access: yesЖурнал Белорусского государственного университета: География, геология, 2021
The article describes the history of studying the diamond content of tectonic structures of the territory of Belarus. Based on the results of magnetometric, mineralogical, tectonic studies carried out by industrial geologists and scientists over the past
Victor S. Konishchev   +1 more
doaj   +1 more source

Proterozoic Geology

open access: yesEos, Transactions American Geophysical Union, 1984
This book and its companion, Early Proterozoic Geology of the Great Lakes Region (Mem. 160 Geological Society of America, 1984), edited by L.G. Medaris, Jr., are the products of an International Proterozoic symposium held at the University of Wisconsin, Madison, May 18–21, 1981.
openaire   +1 more source

Archaean and Proterozoic diamond growth from contrasting styles of large-scale magmatism

open access: yesNature Communications, 2017
Precise dating of diamond growth is required to understand the interior workings of the early Earth and the deep carbon cycle. Here we report Sm-Nd isotope data from 26 individual garnet inclusions from 26 harzburgitic diamonds from Venetia, South Africa.
J. Koornneef   +5 more
semanticscholar   +1 more source

Old subcontinental mantle zircon below Oahu

open access: yesCommunications Earth & Environment, 2021
Oceanic mantle-derived zircon grains recovered from pyroxenite xenoliths in Hawaii have 14-million-year-old rims, Cretaceous cores and Proterozoic lutetium-hafnium model-ages, according to mass spectrometry and electron microprobe analyses.
John D. Greenough   +7 more
doaj   +1 more source

The structure of the Western and Central parts of the Ukrainian schield. Controversial issues

open access: yesГеофизический журнал, 2018
Some controversial issues of composing the Scheme of the fault megablock tectonics of the western half of the Ukrainian shield in connection with the decision of the Interdepartmental Tectonic Committee of Ukraine on drawing up the Tectonic map of the ...
О. B. Gintov   +7 more
doaj   +1 more source

Dating mylonitic overprinting of ancient rocks

open access: yesCommunications Earth & Environment, 2023
The timing of deformation in ancient shear zones of the Akia Terrane, Greenland, is recorded by the Proterozoic Rb-Sr age of mylonitic biotite which is determined through collision cell laser ablation and inverse thermal history modelling.
Christopher L. Kirkland   +6 more
doaj   +1 more source

Proterozoic basins of Canada: Early Proterozoic sequences in Labrador

open access: yes, 1981
Early Proterozoic ( Aphebian) sedimentary and volcanic rocks in Labrador are described from two tectonic belts: the Churchill Province of western Labrador, and the Makkovik Subprovince of eastern Labrador. The Aphebian in the Churchill Province is represented mainly by the Labrador Trough ( Kaniapiskau Supergroup) but also in the Laporte Croup, Lake ...
R J Wardle, D G Bailey
openaire   +1 more source

Trace element and Sr-Nd-Pb isotope geochemistry of Rungwe Volcanic Province, Tanzania: Implications for a superplume source for East Africa Rift magmatism

open access: yesFrontiers in Earth Science, 2014
The recently discovered high, plume-like 3He/4He ratios at Rungwe Volcanic Province (RVP) in southern Tanzania, similar to those at the Main Ethiopian Rift in Ethiopia, strongly suggest that magmatism associated with continental rifting along the entire ...
Paterno R Castillo   +3 more
doaj   +1 more source

Home - About - Disclaimer - Privacy