Results 51 to 60 of about 5,596 (229)

Stratigraphy and uranium potential of Early Proterozoic metasedimentary rocks in the Medicine Bow Mountains, Wyoming

open access: yes, 1979
Stratigraphy and uranium potential of Early Proterozoic metasedimentary rocks in the Medicine Bow Mountains ...
K.E. Karlstrom (8754141)   +1 more
core   +1 more source

P–T Modelling Constrains the Depth of Emplacement of the Porto Azzurro Pluton and Implies Minor Exhumation Caused by the Zuccale Fault (Island of Elba, Italy)

open access: yesJournal of Metamorphic Geology, EarlyView.
ABSTRACT Understanding the pressure of emplacement of granitic intrusions is crucial to understanding the exhumation history of plutons and constraining the tectonic setting of magma emplacement. However, P–T and geochronological constraints from exhumed plutons are often characterized by large uncertainties, especially in shallow crustal settings with
Samuele Papeschi   +4 more
wiley   +1 more source

Chemical and isotopic compositions of Archean magmatic and metasedimentary rocks and minerals from the Podolia domain, Ukrainian Shield

open access: yes, 2013
Zircons from the oldest magmatic and metasedimentary rocks in the Podolia domain of the Ukrainian shield were studied and dated by the U-Pb method on a NORDSIM secondary-ion mass spectrometer.
L M Stepanyuk (8003609)   +15 more
core   +1 more source

Araguainha Dome, Brazil: A polygonal impact structure due to a complex pre‐impact regional structural framework

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract We investigated the structural framework of the north–northwestern Paraná Basin in Brazil to test whether the pre‐impact structures in this region may have had any influence on the first‐order formation and morphostructure of the Araguainha impact structure (AIS).
Renato B. Bernardes   +5 more
wiley   +1 more source

The Vazante and Canastra groups revisited: Sm-Nd and Sr isotopes - evidence for contribution from Tonian intraplate magmatism during passive margin development along the SW São Francisco margin, Brazil

open access: yesBrazilian Journal of Geology, 2019
Combined Sm-Nd isotope studies and U-Pb ages of detrital zircons have shown significant differences between the provenance patterns of Neoproterozoic metasedimentary successions in the Southern Brasília belt.
Manuela de Oliveira Carvalho   +4 more
doaj   +1 more source

From subduction to collision in the northern Tibetan plateau : evidence from the early Silurian clastic rocks, northwestern China [PDF]

open access: yes, 2012
The Qilian Orogen records early Paleozoic collisional suturing of the Qaidam Block and the Central Qilian Block to the North China Craton. The composition and U-Pb age of detrital zircons and the composition of Cr-spinels from the Early Silurian ...
Jianghai Yang   +7 more
core   +1 more source

Evolution Model for the Paleoproterozoic Talvivaara Mudstone‐Hosted Ni‐Zn‐Cu‐Co Deposit in Fennoscandia

open access: yesTerra Nova, EarlyView.
ABSTRACT The Paleoproterozoic Talvivaara mudstone is a very large sulfidic Ni‐Co deposit that records enhanced organic matter accumulation during the global Shunga Event. Here, rock geochemistry and microscale S and Fe isotope composition of in situ pyrrhotites and pyrites are studied in well‐characterised, well‐preserved drill core samples.
Raimo Lahtinen   +3 more
wiley   +1 more source

Ductile Extrusion Triggered by Continental Collision in NE Brazil

open access: yesTerra Nova, EarlyView.
ABSTRACT The Borborema Province in northeastern Brazil hosts one of the world's largest strike‐slip shear zone networks, active during the late Neoproterozoic assembly of West Gondwana. Whether these shear zones initiated during active continental collision or as a post‐orogenic response to far‐field stresses remains debated.
L. R. Tesser   +6 more
wiley   +1 more source

On reasons of specific composition of the Keivy domain rocks (the Kola Peninsula) [PDF]

open access: yesVestnik MGTU, 2017
The Keivy domain differs from the other structures of the Kola region by the specific composition of the metamorphic complexes, the presence of the oldest for the region alkaline granites and gabbroanorthosites associated with them as well as by the ...
Kozlov N. E.   +4 more
doaj   +1 more source

Emergence of Continents Stabilized the Bioavailability of Boron

open access: yesTerra Nova, EarlyView.
ABSTRACT Boron is an essential element for the development of life on Earth; borates stabilize ribose in prebiotic reactions and facilitate metabolism in higher plants. There is, however, a relatively narrow surface boron concentration range over which borates stabilize and serve as a micronutrient rather than a toxin.
Brendan V. Dyck, Jon Wade
wiley   +1 more source

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