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Our current understanding of the rates and timescales of mountain-building processes is largely based on information recorded in U-bearing accessory minerals such as monazite, which is found in low abundance but which hosts the majority of the trace element budget. Monazite petrochronology was used to investigate the timing of crustal melting in migmatitic metasedimentary rocks from the Jomolhari...
A geologic investigation was undertaken in the Hoh-Xil–Songpan-Ganzi (HXSG) complex, northern Tibet in order to better understand magma genesis and evolution during the late stages of Paleo-Tethys ocean closure. The HXSG complex is composed of vast accumulations of Middle–Upper Triassic marine gravity flow deposits that were extensively intruded by igneous rocks. These early Mesozoic rocks exposed...
The Jiaodong Terrane of the Eastern Shandong Complex in the Eastern Block of the North China Craton (NCC) consists predominantly of Archean granitoid gneisses with minor supracrustal rock enclaves or lenses. This study presents new zircon LA-ICP-MS U–Pb and Lu–Hf isotopic data for these lithologies, which help to better understand the Archean crustal evolution of the Eastern Block of the NCC. Magmatic...
We have conducted a whole-rock geochemical, U–Pb zircon geochronological, and in situ zircon Hf–O isotopic compositional study of rocks in southern Tibet from the Langxian igneous suite (including a lamprophyre dyke, mafic enclaves, a granodiorite, and a two-mica granite) and the Nuri igneous suite (a quartz–diorite). U–Pb zircon dating indicates that the timing of crystallization of the mafic enclaves...
We analysed the Mo isotope composition of a comprehensive series of molybdenite samples from the porphyry-type Questa deposit (NM, USA), as well as one rhyolite and one granite sample, directly associated with the Mo mineralization. The δ 98 Mo of the molybdenites ranges between −0.48‰ and +0.40‰, with a median at −0.05‰. The median Mo isotope composition increases from early magmatic (−0...
Granitoids near the Bayan Obo giant rare earth element (REE) deposit at the north margin of the North China Craton (NCC), the world's largest light REE (LREE) deposit, have been taken by some authors as the key factors that controlled the mineralization. In contrast, others proposed that the REE deposit has been partially destructed by these granitoids. Here we report systematic studies on geochronology...
Meso-Archean sedimentary sequences at Mt. Narryer and the Jack Hills of the Narryer Terrane in Western Australia's Yilgarn Craton contain detrital zircon grains with ages as old as 4.37Ga, the oldest preserved terrestrial matter. These grains are rare remnants of Hadean (4.5–4.0Ga) terrestrial crust and their survival stems from the crystallographic properties of zircon during crustal reworking: they...
A combined study of whole-rock major-trace elements and Sr–Nd–Pb–Hf isotopes as well as zircon U–Pb ages and Hf–O isotopes was carried out for Mesozoic andesitic–basaltic volcanics from the Luzong basin in the Middle–Lower Yangtze River Belt, South China. The results provide insights into the origin of mantle sources above fossil Andes-type oceanic subduction zone and thus into the petrogenesis of...
Accretionary orogenic belts are considered the most important sites for the generation of continental crust. However, it is still not very clear whether in such settings the continental crust has been significantly transported back to the mantle accompanied with its lateral growth. Continental UHP rocks, the best indicators of the recycling of the continental crust, have rarely been discovered in...
We have investigated lava flows representative of the whole eruptive history of the Colli Albani ultrapotassic volcanic district (Central Italy). One of the most intriguing features concerning some of these lava flows is the occurrence of primary, magmatic calcite in the groundmass. The primary, magmatic nature of calcite has been inferred by microtextural investigations showing that it typically...
The Yulekenhalasu porphyry copper deposit is located in the Kalaxiange'er metallogenic belt in northern Junggar, China. We present the results from zircon U–Pb geochronology, and geochemical and Sr–Nd–Hf isotope analyses of the granitoids associated with the ore deposits with a view to constrain their petrogenesis and tectonic setting. The granitoids consist of quartz diorite, diorite porphyry, porphyritic...
Field and petrographic observations combined with major and trace element bulk rock geochemistry show that metabasic rocks within Val Strona di Omegna in the central Ivrea Zone partially melted during granulite facies regional metamorphism. A transition from granoblastic amphibolite facies metabasic rocks at the lowest metamorphic grades to metatexitic and diatexitic migmatites in the granulite facies...
The crustal structure of the Tibetan Plateau records the dynamic processes of several terranes that underwent disaggregation, aggregation, and amalgamation. The dynamic evolution of continental crusts is best understood from these three processes. However, the detailed geochemical province division of the Tibetan Plateau and the palaeo-tectonic affinity or evolution of terranes remains unclear. In...
Following the amalgamation of the late Mesoproterozoic–Carboniferous Central Asian Orogenic Belt with the Siberian and North China cratons, NE China underwent late Mesozoic lithospheric extension and widespread formation of volcano-sedimentary basins. We report U–Pb zircon ages and geochemical data for mafic and felsic volcanic rocks from the Hailar basin, located about 1000km north of Beijing. Zircon...
This contribution presents the first detailed three-dimensional (3D) in situ analysis of samples from the Platinova Reef using high-resolution X-ray computed tomography (HRXCT) and 3D image processing and quantification coupled with microscopic and mineralogical investigations. Our HRXCT analyses reveal the complex textural relationships between Cu-rich sulfides (bulk composition close to bornite),...
We investigated high temperature Mo isotope fractionation in a hydrous supra-subduction volcano-plutonic system (Kos, Aegean Arc, Greece) in order to address the debate on the δ 98/95 Mo variability of the continental crust. In this igneous system, where differentiation is interpreted to be dominated by fractional crystallization, bulk rock data from olivine basalt to dacite show δ 98/95...
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