Showing papers in "Gondwana Research in 2009"

TL;DR: In this article, the authors evaluate the global age distribution of granitoid magmatism and juvenile continental crust production with U/Pb isotopic ages from igneous and detrital zircons, and with Nd isotopic data.

TL;DR: In this paper, a model involving Pacific-type orogeny was proposed to explain the Neoproterozoic evolution of southern India and its final amalgamation within the Gondwana assembly.

TL;DR: The assembly of the supercontinent Columbia at about 1.85-1.90 ǫ-Ga coincided with several events that affected the entire earth, including rapid increase in the concentration of oxygen in the atmosphere and oceans and probably the evolution of eukaryotes as discussed by the authors.

TL;DR: In this paper, the authors identify two major types of subduction zones on the globe: the Circum-Pacific subduction zone and the Tethyan subduction Zone and propose the tectonic framework leading to the future supercontinent Amasia 250 million years from present, with the present day Western Pacific region as its frontier.

TL;DR: The Xiong'er volcanic belt was most likely a Paleo-Mesoproterozoic continental magmatic arc that formed at the southern margin of the North China Craton.

TL;DR: The Dabie-Sulu Triassic orogen in central-eastern China was created by northward subduction of the Yangtze cratonal plate beneath the Sino-Korean craton.

TL;DR: In this paper, the authors examined the extensive regions of Proterozoic accretionary belts that either formed most of the Amazonian Craton, or are marginal to its southeastern border.

TL;DR: In this article, the authors present Sensitive High Resolution Ion Microprobe (SHRIMP) U and Pb isotope analyses of zircon from a charnockite and a charnsockite-hosted leucosome in order to determine the age of magmatism and anatexis related to high-grade metamorphism immediately to the north of the Palghat Cauvery Shear System (PCSS), a proposed Neoproterozoic terrane boundary within Southern India.

TL;DR: In this paper, the authors reviewed occurrences of Late Neoproterozoic-Mesozoic seamounts of the Paleo-Asian and Paleo-Pacific oceans, which are hosted by accretionary complexes (ACs) of Russian Altai, East Kazakhstan, Mongolia, Russian Far East and Japan.

TL;DR: In this article, the authors introduce the methodology of multiscale seismic tomography and the way to interpret the obtained tomographic images, and then review the significant recent results of multi-scale seismic imaging with emphasis on mantle plumes and subducting slabs.

TL;DR: In this paper, geochemical analyses of K-bentonites show that the parent magma originated in syn-collisional, volcanic-arc and within-plate tectonic settings, which produced mainly intermediate-to-felsic series magmas associated with continuous collision and subduction of paleo-continental blocks/arcs.

TL;DR: Coltice et al. as discussed by the authors used 3D numerical simulations of mantle convection to show that the mantle global warming model could explain the peculiarities of magmatic provinces that developed during the formation of Pangea and Rodinia, as well as putative Archaean supercontinents such as Kenorland and Zimvaalbara.

TL;DR: In this article, the authors present new pieces of evidence from seismology and mineral physics for the existence of low-velocity zones in the deep part of the upper mantle wedge and the mantle transition zone that are caused by fluids from the deep subduction and deep dehydration of the Pacific and Philippine Sea slabs under western Pacific and East Asia.

TL;DR: In this article, the authors classified the upper mantle in this region into three major domains: (a) metasomatic-metamorphic factory (MMF), subduction zone magma factory (SZMF), and the big mantle wedge (BMW).

TL;DR: In this paper, the Rangit duplex (RD) was reconstructed from the original Lesser Himalayan Sequence (Gondwana, Buxa, Upper Daling) in the Darjeeling - Sikkim Himalaya.

TL;DR: In this paper, the authors pointed out that a significant change in the geodynamo in the outer core of the planet after a 50 million years of stable geomagnetism was likely led by the appearance of a thermal instability at the 2900 km-deep core-mantle boundary in connection with mantle superplume activity.

TL;DR: In this paper, the authors proposed a model that involves a volcanic arc formed by northward subduction of the ancient Junggar ocean and amalgamation of different terranes during the Late Paleozoic to interpret the formation of the Late Devonian volcanic rocks in the Eastern Junggars terrane, and they presented major element, trace element and Sr-Nd isotopic analyses of 64 (ultra)mafic to intermediate volcanic rock samples of these formations.

TL;DR: In this article, the authors used the available data to develop an integrated plume-lithosphere interaction model for the mid-Neoproterozoic South China block, and calculated the primary MgO, FeO, and SiO 2 contents of basalts through carefully selecting less-evolved samples using a melting model.

TL;DR: In the early half of the Earth history, the felsic continental crust on the surface which formed in an intra-oceanic environment has mostly been subducted into the deep mantle, except in the rare case of parallel arc collision.

TL;DR: In this paper, late-stage Pan-African granitoids, including monzogranite, syenogranites, and alkali granite, were collected from four separate localities in Sinai.

TL;DR: In the early Neoproterozoic, the onset of subduction in the interior (Rheic) ocean was coeval with a major change in the tectonic regime in the exterior (paleo-Pacific) ocean, suggesting a geodynamic linkage between these events.

TL;DR: In this paper, the authors reviewed the mechanism of earthquake and magma generation associated with plate subduction and showed that water released by dehydration of the slab and secondary convection in the mantle wedge, mechanically induced by slab subduction, are responsible for magma generating in the Japanese islands.

TL;DR: In this article, the authors classified low-MgO-Ni-Cr and high-mgO−Ni−Cr into two groups: low MgO samples were derived from partial melting of thickened lower crust, whereas high Mg O samples were melts from delaminated lower crust which subsequently interacted with mantle peridotite upon ascent.

TL;DR: The petrographic results for the Baogutu porphyry copper belt recognize them as diorite stocks rather than the granodiorite porphyries as previously identified as mentioned in this paper.

TL;DR: Zhang et al. as discussed by the authors proposed a new model for the origin of the Xiong'er volcanic belt and considered it to be a Paleo-Mesoproterozoic continental magmatic arc.

TL;DR: In this paper, SHRIMP analyses of zircons from three metarhyolites of the Kangbutiebao Fm. in the Kelang Basin yield weighted mean 206 Pb/ 238 U ages of 412.6−3.5−5.3

TL;DR: In this article, the authors document a Palaeoproterozoic Andean-type continental arc granitoid emplacement event in the northwestern segment of the Aravalli mountain range, NW India, in good agreement with a zircon Pb-Pb evaporation age of 1821.

TL;DR: Based on geochronologic data and regional geological evidence, it is suggested that the mineralization in the Xilamulun belt was formed during multiple events as discussed by the authors, including a post-collisional extension stage, a tectonic stress transformation from NS to EW, and a lithospheric thinning stage.

TL;DR: In this paper, the authors show that bottom-up mantle convection, including voluminous plume ascent, efficiently rid the planet of heat, but lessened over time, and plate thickening and broadening is reflected in the post-Hadean rock record.

TL;DR: In this paper, the bulk density variations of some representative compositions for the lower mantle based on the pressure-volume-temperature equation of state of the constituent mineral phases were investigated at a temperature of 300 k and at lower mantle pressures.