نتایج جستجو برای: OIB-like volcanism

تعداد نتایج: 656131  

Journal: :iranian journal of earth science 0
farhad moharami department of geology, payame noor university issa azadi faculty of earth science, shahid beheshti university, tehran, iran mirsaleh mirmohamadi school of mining engineering, faculty of engineering, university of tehran, iran javad mehdipour ghazi faculty of earth science, shahid beheshti university, tehran, iran mohammad rahgoshay faculty of earth science, shahid beheshti university, tehran, iran

chaldoran area in nw of iran has mesozoic oceanic crust basement. the studied rocks of this region can be divided into three groups: ophiolitic gabbros and pillow lavas, ophiolitic volcanoclastics and eocene lava flows. ophiolitic mafic rocks show continental volcanic arc natures and eocene lava flow shows oib-like nature. during the mesozoic,the chaldoran region was situated in the active cont...

Farhad Moharami Issa Azadi Javad Mehdipour Ghazi Mirsaleh Mirmohamadi Mohammad Rahgoshay

Chaldoran area in NW of Iran has Mesozoic oceanic crust basement. The studied rocks of this region can be divided into three groups: ophiolitic gabbros and pillow lavas, ophiolitic volcanoclastics and Eocene lava flows. Ophiolitic mafic rocks show continental volcanic arc natures and Eocene lava flow shows OIB-like nature. During the Mesozoic,the Chaldoran region was situated in the active cont...

2018
Quanshu Yan Xuefa Shi Ian Metcalfe Shengfa Liu Taoyu Xu Narumol Kornkanitnan Thanyapat Sirichaiseth Long Yuan Ying Zhang Hui Zhang

Intraplate volcanism initiated shortly after the cessation of Cenozoic seafloor spreading in the South China Sea (SCS) region, but the full extent of its influence on the Indochina block has not been well constrained. Here we present major and trace element data and Sr-Nd-Pb-Hf isotope ratios of late Cenozoic basaltic lavas from the Khorat plateau and some volcanic centers in the Paleozoic Sukh...

2013
Zong-Feng Yang Jun-Hong Zhou

The nature of source rocks of basaltic magmas plays a fundamental role in understanding the composition, structure and evolution of the solid earth. However, identification of source lithology of basalts remains uncertainty. Using a parameterization of multi-decadal melting experiments on a variety of peridotite and pyroxenite, we show here that a parameter called FC3MS value (FeO/CaO-3*MgO/SiO...

2017
Mark Edwards

Introduction Ocean island basalts (OIB) are thought to sample the Earth’s deep mantle, whereby thermochemical plumes entrain lower mantle material and bring it to the surface where it erupts. By measuring the isotopic compositions of global OIB—which record the isotopic compositions of OIB mantle sources—geochemists can “map” the isotopic heterogeneity of the Earth’s deep mantle (e.g., Gast et ...

2010
Guillaume Bronsard Michel Botbol Sylvie Tordjman

BACKGROUND Parents, caregivers and mental health professionals have often reported violence and aggression in children or adolescents with autistic disorder. However, most of these observations derived from anecdotal reports, and studies on frequency and characterization of aggression in autism remain limited. Our objective was to better characterize and understand the different types of aggres...

2016
N. A. Starkey S. Parman M. Jackson

Measurements of Xe isotope ratios in ocean island basalts (OIB) suggest that Earth’s mantle accreted heterogeneously, and that compositional remnants of accretion are sampled by modern, high-He/He OIB associated with the Icelandic and Samoan plumes. If so, the high-He/He source may also have a distinct oxygen isotopic composition from the rest of the mantle. Here, we test if the major elements ...

2017
S. Parman

Measurements of Xe isotope ratios in ocean island basalts (OIB) suggest that Earth’s mantle accreted heterogeneously, and that compositional remnants of accretion are sampled by modern, high-He/He OIB associated with the Icelandic and Samoan plumes. If so, the high-He/He source may also have a distinct oxygen isotopic composition from the rest of the mantle. Here, we test if the major elements ...

2010
Pranab Das Sridhar D Iyer

The geochemical discriminate diagrams help to distinguish the volcanics recovered from different tectonic settings but these diagrams tend to group the ocean floor basalts (OFB) under one class i.e., as mid-oceanic ridge basalts (MORB). Hence, a method is specifically needed to identify the OFB as normal (N-MORB), enriched (E-MORB) and ocean island basalts (OIB). We have applied Artificial Neur...

2009
Esteban Gazel Michael J. Carr Kaj Hoernle Mark D. Feigenson David Szymanski Paul van den Bogaard M. J. Carr K. Hoernle M. D. Feigenson D. Szymanski F. Hauff

[1] Although most Central American magmas have a typical arc geochemical signature, magmas in southern Central America (central Costa Rica and Panama) have isotopic and trace element compositions with an ocean island basalt (OIB) affinity, similar to the Galapagos-OIB lavas (e.g., Ba/La < 40, La/Yb > 10, Pb/Pb > 18.8). Our new data for Costa Rica suggest that this signature, unusual for a conve...

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