Results 81 to 90 of about 29,339 (247)

Salt Range Formation of Pakistan Preserves Unique Record of Volcanic Fertilization During the Ediacaran Shuram Excursion

open access: yesTerra Nova, EarlyView.
ABSTRACT Thin, discontinuous, organic‐rich oil shale beds in the siliciclastic‐evaporitic Salt Range Formation (SRF) of Pakistan are of approximate Neoproterozoic to Cambrian age based on stratigraphic constraints. The beds are enriched (26–43 wt.% total organic carbon, TOC) in aliphatic organic matter (OM) of low thermal maturity despite their ...
Paul C. Hackley   +4 more
wiley   +1 more source

Chemical composition of sandstones and paleogeodynamic reconstructions

open access: yesЛитосфера, 2016
The article analyzes the adequacy of compliance on paleogeodynamic nature of Upper Precambrian sedimentary associations - Bashkir meganticlinorium, Kama-Belaya aulacogene and Uchur-Maya region, received by geological methods and by using discriminant ...
A. V. Maslov   +3 more
doaj   +2 more sources

High-alumina gneisses of the Chupa Formation in the Belomorian Mobile Belt: metamorphic conditions, partial melting, and the age of migmatites

open access: yesЗаписки Горного института
Migmatized gneisses of the Chupa paragneiss Formation in the Belomorian Mobile Belt (BMB) of the Fennoscandian Shield have been studied, and the conditions of partial melting during high-grade metamorphism of the rocks were determined.
Anastasiya V. Yurchenko   +2 more
doaj  

Geochemistry of Zircon from Pegmatite-bearing Leucogranites of the Laghman Complex, Nuristan Province, Afghanistan

open access: yesRussian Journal of Earth Sciences
For the first time, a study was carried out on the geochemistry of zircon (SIMS method, 2 samples, 20 points) from leucogranites of the Laghman complex, located in the pegmatite-bearing (LCT-type) province of Nuristan (Afghanistan).
Levashova Ekaterina Valer'evna   +4 more
doaj   +1 more source

U–Pb Dating of Cambrian Magmatism in the Pinerolo‐Sanfront Unit, Dora‐Maira Massif (Western Alps)

open access: yesTerra Nova, EarlyView.
ABSTRACT The Pinerolo‐Sanfront Unit (PSU), the structurally lowest tectonic unit of the Dora‐Maira Massif (Western Alps), has been regarded as a monocyclic unit composed of Permo‐Carboniferous sediments and Permian granitoids that were metamorphosed during the Alpine orogeny.
Francesco De Cesari   +6 more
wiley   +1 more source

Multi‐Mineral Geochronology Across the Neoproterozoic Brasília Nappe Stack: Constraints on Thermal Resetting and Metamorphic Architecture

open access: yesTerra Nova, EarlyView.
ABSTRACT The Southern Brasília Orogen formed during Western Gondwana's final assembly and comprises nappe systems piled against the São Francisco Craton. We present new rutile U–Pb ages from the lowermost Canastra Group (> 2.2 Ga) and the uppermost Carrancas Group (~560 Ma), integrated with published zircon, monazite, garnet, and mica ages from the ...
Rodrigo Irineu Cerri   +7 more
wiley   +1 more source

The AGeS2 (Awards for Geochronology Student research 2) Program: Supporting Community Geochronology Needs and Interdisciplinary Science [PDF]

open access: yes, 2018
Geochronology is essential in the geosciences. It is used to resolve the durations and rates of earth processes, as well as test causative relationships among events.
Metcalf, James R.   +5 more
core   +1 more source

Sr-Nd Systematics and REE distribution in the type magnesite deposits in Lower Riphean of South Urals province

open access: yesЛитосфера, 2016
The geochemistry and REE of magnesite and host carbonate rocks of two Lower Riphean deposits of the South Urals province (Satka and Ismakaevo ore fields) confirm the metasomatic nature of the magnesite.
M. T. Krupenin   +2 more
doaj   +2 more sources

Mineralogy and thermobarometry of the Kalevian volcano-plutonic complex of the Kaskama block (Inari Terrane, Kola-Norwegian Region, Fennoscandian Shield)

open access: yesЗаписки Горного института
The petrogenesis and evolution of metamorphic rocks of the volcano-plutonic units of the Kaskama block of the Inari Terrane in northwestern Russia were studied.
Aleksandr B. Vrevsky   +2 more
doaj  

Uncertainty in helium diffusion in zircon limits thermochronologic resolution: application to the Great Unconformity [PDF]

open access: yesGeochronology
Thermochronology provides a unique perspective on the timing and magnitude of erosion during the generation of unconformities. Recently, thermochronology has been used to reinvigorate a long-standing debate about the origin of the Great Unconformity, a ...
M. Fox   +6 more
doaj   +1 more source

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