نتایج جستجو برای: oib like volcanism
تعداد نتایج: 656131 فیلتر نتایج به سال:
Mud volcanism was initiated when overpressured muds rose through the Mediterranean Ridge accretionary prism. Early mud volcanism was marked by eruption of coarse clastic sediments forming small cones of debris flow deposits and turbidites, followed by eruption of large volumes of clast-rich matrix-supported debris flows. Eruption was accompanied by progressive subsidence to form moat-like featu...
The effect of octaisobutyl-polyhedral oligomeric silsesquioxane (OIB-POSS) as a nanosized reinforcement on the cure kinetics, crosslinking density, and mechanical properties styrene-butadiene rubber (SBR) nanocomposites was examined in this study. For purpose, SBR compounds with various OIB-POSS nanoparticle loadings at 1, 3, 5 phr were prepared their results compared reference compound without...
A fundamental challenge in modern mantle geochemistry is to link geochemical data with geological and geophysical observations. Most of the early geochemical models involved a layered mantle and the concept of geochemical reservoirs. Indeed, the two layer mantle model has been implicit in almost all geochemical literature and the provenance of oceanic island basalt (OIB) and mid-ocean ridge bas...
We provide estimates of volcanism versus time for planets with Earth-like composition and masses 0.25 25 M⊕, as a step toward predicting atmospheric mass on extrasolar rocky planets. Volcanism requires melting of the silicate mantle. We use a thermal evolution model, calibrated against Earth, in combination with standard melting models, to explore the dependence of convection-driven decompressi...
Abstract Bimodal volcanism occurs in a range of extensional environments that are characterized by distinctive but overlapping, lithogeochemical and isotopic signatures lithological assemblages. Where basaltic magmatism is associated with ferroan (A‐type) rhyolites, it typically the lithogeochemistry systematics rocks most beneficial constraining tectonic evolution. This study presents geochemi...
The Paleocene-Eocene thermal maximum (PETM) has been attributed to a sudden release of carbon dioxide and/or methane. 40Ar/39Ar age determinations show that the Danish Ash-17 deposit, which overlies the PETM by about 450,000 years in the Atlantic, and the Skraenterne Formation Tuff, representing the end of 1 +/- 0.5 million years of massive volcanism in East Greenland, are coeval. The relative ...
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...
Numerous research data have been obtained about the Sumdo Palaeo‐Tethys, but reports on occurrence of Permian Ocean islands are relatively scarce. Here, we present zircon U–Pb geochronology, geochemistry, and in situ Hf isotopic characteristics ocean island basalt (OIB)‐type gabbros from Ewulang Nianqing‐Sumdo, Tibet. The age OIB‐type is 263 Ma (the Middle Permian), representing formation gabbr...
The Earth’s mantle exhibits marked chemical heterogeneity. We provide an examination of thallium systematics in ocean island basalts (OIB): new high-precision trace element analyses, including Tl, and Tl isotopic compositions for 48 OIB spanning the entire range observed Sr-Nd-Hf-Pb isotope ratios. All investigated are characterised by ubiquitous depletion requiring sources to have concentratio...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید