نتایج جستجو برای: the lower triassic rocks indicate
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Amphibolites in the studied area have upper Triassic age and seen with various rocks such as micaschiste, marble and metadolomite. These rocks with dark and green color contain minerals as hornblende, plagioclase, actinolite, tremolite and epidote that dark and light minerals were separated and seen as dark and light bands. Based on whole rock geochemical analysis, these rocks belong to sub-alk...
The intrusive bodies of Central Alborz, with display lithological composition, include olivine gabbro, olivine monzodiorite, olivine monzonite and pyroxene monzonite. They are accompanied by pyroclastic rocks of the Karaj Formation, and they occur as sill, lopolith, stock and plug. The essential minerals of these rocks are plagioclase, alkali feldspar, pyroxene, olivine and biotite. Mineral che...
The plutonic bodies in northeast of the Sonqor area is a small part of the Sanandaj-Sirjan zone. According to the field and microscopic observations, the study area is composed of two major units; massive rocks (hornblende gabbro, intermediate and felsic rocks) and dikes (pyroxene gabbro). Mineralogical and geochemical studies show that this granitoide compelex is I-type, calk-alkaline and meta...
the speech act of disagreement has been one of the speech acts that has received the least attention in the field of pragmatics. this study investigates the ways power relations, social distance, formality of the context, gender, and language proficiency (for efl learners) influence disagreement and politeness strategies. the participants of the study were 200 male and female native persian s...
Conodonts are the most important fossil remains from the largest Phanerozoic extinction as well as the mass extinction of the late Paleozoic and could be used for exact dating during this period. Triassic deposits located in the Elikah Formation contain exposures in most of the Alborz sections as well as the Zal section in northwestern Iran. In this study, the Elikah Formation was investigated ...
Generally Early Triassic floras are believed to be depauperate, suffering from protracted recovery following the Permian-Triassic extinction event. Here we present palynological data of an expanded East Greenland section documenting recovered floras in the basal Triassic (Griesbachian) and a subsequent fundamental floral turnover, postdating the Permian-Triassic boundary extinction by about 500...
The discovery of the first definitively correlated earliest Jurassic (200 million years before present) tetrapod assemblage (Fundy basin, Newark Supergroup, Nova Scotia) allows reevaluation of the duration of the Triassic-Jurassic tetrapod extinction event. Present are tritheledont and mammal-like reptiles, prosauropod, theropod, and ornithischian dinosaurs, protosuchian and sphenosuchian croco...
Intrusion of the Chahghand gabbrodiorite in regionally metamorphosed rocks of the Sanandaj-Sirjan zone in NE of Neyriz has caused contact metamorphism. A variety of pelitic hornfelses are formed as a result of thermal metamorphism. Spatial distribution of minerals in the Chahghand aureole defines three mineralogical zones namely cordierite, andalusite and sillimanite zones. Study of metamo...
The tectonic evolution of the Paleo-Jinshajiang Ocean, and in particular time its closure, is debated. Here we present new constraints on this region from an integrated paleomagnetic geochronologic study Late Triassic Batang Group volcanic rocks Qamdo, Eastern Qiangtang Terrane (EQT). Two zircon U-Pb ages indicate that erupted at ∼227–222 Ma. New results yield a robust paleopole 57.6°N, 176.4°E...
The initiation of a continental rift or the birth an oceanic basin, and their long-term evolution, are challenges in understanding evolution regional global tectonics. Rifts develop within interior margins plates, essentially as extensional structures, they have been studied widely since discovery plate eastern segment Paleo-Tethys traversed central Asia, its structural features, timing, geolog...
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