Recycling Argon through Metamorphic Reactions: the Record in Symplectites [PDF]
The 40Ar/39Ar ages of metamorphic micas that crystallized at high temperatures are commonly interpreted as cooling ages, with grains considered to have lost 40Ar via thermally-driven diffusion into the grain boundary network.
Allaz+82 more
core +2 more sources
Petrography, geochemistry and mineral chemistry of the Almogholagh intrusive rocks (Hamedan, Iran): Evidences for their shallow-level emplacement [PDF]
The Almogholagh plutonic body with about 10 km2 is located 15 km of West of Hamedan city and on the Sanandaj-Sirjan zone. The Almogholagh pluton consists of diorite and gabbroic diorite, monzodiorite, quartz monzodiorite, monzonite, quartz monzonite ...
Hossein Shahbazi+6 more
doaj +1 more source
Evidence for a reducing Archean ambient mantle and its effects on the carbon cycle [PDF]
Chemical reduction-oxidation mechanisms within mantle rocks link to the terrestrial carbon cycle by influencing the depth at which magmas can form, their composition, and ultimately the chemistry of gases released into the atmosphere.
Aulbach, Sonja, Stagno, Vincenzo
core +1 more source
U-Pb SHRIMP zircon dating of Grenvillian metamorphism in Western Sierras Pampeanas (Argentina) : correlation with the Arequipa-Antofalla craton and constraints on the extent of the Precordillera Terrane [PDF]
The Sierras Pampeanas of Argentina, the largest outcrop of pre-Andean crystalline basement in southern South America, resulted from plate interactions along the proto-Andean margin of Gondwana, from as early as Mesoproterozoic to Late Paleozoic times (e ...
C. Mark Fanning+31 more
core +4 more sources
Micro-XANES determination of ferric iron and its application in thermobarometry
Micro-X-ray absorption near-edge structure (XANES) analysis was employed to determine the content of ferric iron in minerals formed in ultrahigh-pressure (UHP) eclogites. It is observed that omphacite and phengite contain significant amounts of Fe3+/Fetot (0.2–0.6), whereas only very low contents are present in garnet (Fe3+/Fetot=0.0–0.03), the latter ...
Schmid, R.+6 more
openaire +6 more sources
We present a petrologic study of the post-collapse rhyolites from Valles Caldera (New Mexico, USA) to evaluate changes in magmatic storage conditions following the eruption of the Upper Bandelier Tuff (UBT). We assess likely phenocrysts through textures,
Magdalen Grismer, Laura Waters
doaj +1 more source
Introduction The Aliabad area is located in the northwest of Nain. Volcanic rocks of the Aliabad area have andesitic to rhyolitic composition. On the basis of petrographic investigations, porphyritic texture is the main texture of these rocks.
Rezvan Mehvari, Mortaza Sharifi
doaj +1 more source
Garnet-Amphibolites Mineralogy and thermobarometry in Aliabad-Damagh (south of Hamedan, Sanandaj-Sirjan Zone) [PDF]
The garnet-amphibolites in Aliabad-Damagh area, occurs as layers and are enveloped by staurolite-schist. They composed predominantly of garnet, hornblende, feldspar (± muscovite and quartz) with titanite, epidote, ilmenite and graphite as accessory ...
Ali Akbar Baharifar+3 more
doaj +1 more source
The Mesozoic along-strike tectono-metamorphic segmentation of Longmen Shan (eastern Tibetan plateau) [PDF]
The Longmen Shan belt (eastern border of the Tibetan plateau) constitutes a tectonically active region as demonstrated by the occurrence of the unexpected 2008 Mw 7.9 Wenchuan and 2013 Mw 6.6 Lushan earthquakes in the central and southern parts of the ...
A. Robert+80 more
core +2 more sources