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In Central China, long-distance effects from collision between the North China and Yangtze cratons, uplift of the Tibetan Plateau and subduction of the Pacific Ocean are believed to converge in the Western Qinling. Mantle xenoliths from Baiguan and Haoti kamafugites in the Western Qinling were investigated to understand the lithospheric structure and mantle metasomatism beneath the orogenic belt....
Extensive (about 5000km 3 ) basaltic magmas erupted on the Hainan Island, south China, mostly during the past 1millionyears. U–Th disequilibrium data as well as Nd, Sr, Pb isotopes and major and trace element concentrations were measured on the youngest lavas from Maanling volcano and Leihuling volcano of the Hainan Island. All the Holocene Hainan basalts display light rare earth element (LREE)...
Mineralization at Maldon, Victorian goldfields, Australia, is part of the Western Lachlan Foldbelt and is hosted by deformed Lower Ordovician metasediments intruded by the Late Devonian Harcourt Granite. Gold–Bi–Te–S associations in the deposit include four gold-bearing minerals (maldonite, native gold, jonassonite, and aurostibite) and a range of sulphotellurides from the tetradymite group, all of...
The origin of the Quaternary silicic rocks in Iceland is thought to be linked to the thermal state of the crust, which in turn depends on the regional tectonic settings. This simple model is tested here on rocks from the Miocene to present, both to suggest an internally consistent model for silicic magma formation in Iceland and to constrain the link between tectonic settings and silicic magma petrogenesis...
A systematic study of textural and compositional zoning (An% and FeO variation) in plagioclase phenocrysts of historic (pre-1971) and recent (post-1971) lavas at Mount Etna was made through back-scattered electron (BSE) images and electron microprobe analyses (EMP). The textures considered include oscillatory zoning and several types of dissolution, resorption and growth textures at the phenocryst...
The age of high-pressure metamorphism is crucial to identify a suitable tectonic model for the vast Variscan orogeny. Banded HP granulites from the Gesso-Stura Terrain in the Argentera Massif, Italy, have been recently described (Ferrando et al., 2008) relicts of high-pressure metamorphism in the western part of the Variscan orogen. Bulk rock chemistry of representative lithologies reveals intermediate...
The Gümüşhane pluton, a high-K calc-alkaline I-type granodiorite/granite complex, forms an important component of the pre-Liassic basement of the Eastern Pontides (NE Turkey). In its eastern part, the pluton shows a compositional zonation ranging from biotite–hornblende granodiorite in the NW through biotite–hornblende granite to leucogranite/granophyre in the SE. Numerous mafic microgranular enclaves...
Mechanisms of interaction between a carbonatite magma and a silicate magma are inferred on the basis of the textural and geochemical features of a carbonate-bearing tuff from the Massif Central, characterized by the presence of carbonatite globules within a silicate glass matrix. A two-fluid dynamical model is proposed in order to constrain the formation of the carbonatite globules that underwent...
The A Silva granodiorite is a plutonic body intruded into the metasediments of the upper unit of the Órdenes Complex (Variscan belt, NW Spain). These metasediments represent the middle section of a magmatic arc located in northern Gondwana. The A Silva granodiorite has been classically considered a late Variscan granite. In this work, new field mapping, structural analysis, and SHRIMP U–Pb zircon...
Titanite, TiO 2 , and pseudorutile are associated with primary igneous Fe-oxide grains in basalt and rhyolite clasts from the Keweenaw Peninsula, Michigan, USA which were metamorphosed to the prehnite–pumpellyite facies. Pseudorutile occurs with titanite+TiO 2 in broad lamellae within titaniferous magnetites. It also occurs as intergrowths with titanite and Fe-oxide in embayments within...
The crust in southern Mongolia is part of the Central Asian Orogenic Belt, a vast accretionary orogen that records the opening and closure of the Palaeo-asian Ocean in the late Proterozoic to Palaeozoic. The crustal evolution of the region is revealed in basement inliers that also contain intrusion-related porphyry ore bodies that are important mineral exploration targets. The Saykhandulaan inlier...
The remnants of the Neotethyan Izmir–Ankara Ocean, the main branch of Neotethys in the eastern Mediterranean are represented by the Dagküplü Melange Complex in Central Sakarya, NW Turkey. It comprises several blocks or tectonic slices of pillow lavas, some of which include mudstones and radiolarian cherts as intra-pillow-fillings or interlayers. In the Igdecik area, a huge basaltic block has been...
Late tectonic, post-collisional granite suites are a feature of many parts of the Late Neoproterozoic to Cambrian East African Orogen (EAO), where they are generally attributed to late extensional collapse of the orogen, accompanied by high heat flow and asthenospheric uprise. The Maevarano Suite comprises voluminous plutons which were emplaced in some of the tectonostratigraphic terranes of northern...
The Fosdick migmatite–granite complex in West Antarctica records evidence for crustal melting during two periods of tectonism along the East Gondwana margin. Initial high-temperature metamorphism in the Devonian–Carboniferous (M 1 ) was broadly contemporaneous with emplacement of calc-alkaline arc magmas during Pacific-style accretionary margin convergence. This event involved metamorphism...
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