نتایج جستجو برای: post-collision volcanism

تعداد نتایج: 453614  

Habib Biabangard Javad Mehdipour Ghazi Mohammad Reza Ghasempour Rahim Dabiri

Both the Sistan Suture Zone of eastern Iran and the Nehbandan Fault contain Plio-Quaternary Nehbandan mafic lavas. Positive anomalies in the large ion lithophile elements (LILE) and negative anomalies in Nb (niobium) exist in these mafic lavas. This indicates the occurrence of subduction magmatism and post-collision volcanism. Petrologic and geochemical analyses distinguished two groups of lava...

2017
J. Wright D. A. Rothery M. R. Balme S. J. Conway

Introduction: The globally extensive smooth plains of Mercury are believed to be mostly volcanic in origin [1]. Widespread effusive volcanism on Mercury is thought to have ended by ~3.5 Ga due to secular cooling of the planet’s interior, and contraction of its lithosphere [2]. As the planet cools and contracts, melt should be produced at a slower rate and in smaller volumes, so it will stall de...

Journal: :journal of tethys 0

we present new whole major and trace elements data for a suite of adakitic dacite to rhyolite rocks from the sahand region. these rocks formed in the pliocene to pleistocene during the the collision between the arabian and eurasian plates following subduction of neo–tethys ocean. these subvolcanic intrusions were emplaced into late cretaceous and eocene sedimentary، volcano–clastic and volcanic...

The Eocene volcanic rocks exposed in the NW Sechangi area of Lut block, include pyroclastic deposits and lavas. These volcanic rocks are basalt, basaltic andesite, andesite, andesite-trachyandesite, trachydacite, dacite and rhyolite-ignimbrite in composition. Based on our field observations, the volcanic rocks erupted in four stages in the aquous to subaerial environments. The volcanic rocks ar...

2013
Claudio Faccenna Thorsten W. Becker Laurent Jolivet Mehmet Keskin

The Middle East region represents a key site within the Tethyan domain where continental break-up, collision, backarc extension and escape tectonics are kinematically linked together. We perform global mantle circulation computations to test the role of slab pull and mantle upwellings as driving forces for the kinematics of the Arabia–Anatolia–Aegean (AAA) system, evaluating different boundary ...

Journal: :journal of mining and environment 0
a. entezari harsini department of geology, ferdowsi university of mashhad, mashhad, iran s. a. mazaheri department of geology, ferdowsi university of mashhad, mashhad, iran s. saadat department of geology, mashhad branch, islamic azad university, mashhad, iran j. f. santos department of geosciences, geobiotec research unit, university of aveiro, aveiro, portugal

this paper presents the new geochemical isotopes sr and nd, and the mineralization data for the south neyshabour volcanic rocks located in ne iran. based on the chemical classifications, the studied rocks are basaltic trachy andesite, trachy andesite, trachyte, and trachy dacite in composition. all the analyzed volcanic rocks display enrichment in light rare earth elements (lree) relative to th...

2002
Alexander T. Basilevsky James W. Head

[1] We investigated the possibility of significant variations in the rates and styles of volcanism and rifting during the time postdating the formation of regional plains on Venus. We analyzed the age relations of all known impact craters 30 km in diameter (183 craters) with the neighboring geologic units. Of these we selected 164 craters which were superposed on regional plains and determined ...

2010
Timothy J. McCoy

As Earth evolved over the last 4.5 billion years, its mineralogy changed. As we peer back through Earth’s history, it seems logical to think that our lens would grow increasingly fogged and our light ever more dim. How do we see beyond the oldest preserved rocks and minerals, after billions of years of volcanism, plate tectonics, and weathering? How do we see past the Moon-forming collision, wh...

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