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Zircon SHRIMP U–Pb ages and cathodoluminescence (CL) images reveal that most zircon separated from two tonalitic gneiss samples in the northern Dabie high T/P metamorphic zone (NDZ) have four different domains: (1) inherited core, with clear oscillatory zoning, low-P mineral inclusions and high Th/U ratios, indicating the Neoproterozoic age of the protolith; (2) inner-mantle, with homogeneous CL intensity,...
The North China craton (NCC) was stabilized in Paleo-Proterozoic times, and the eastern part of it was remobilized in the Mesozoic, as is indicated by the presence of voluminous Mesozoic magmas in eastern NCC. In particular, the lithospheric mantle beneath eastern NCC was significantly thinned during the intense Mesozoic tectono-magmatic activity, which makes the NCC different from most other ancient...
Multiple subduction events occurred preceding the collision of Greater India with the Karakoram terrane that consumed the Neotethyan Ocean between Early Cretaceous and Eocene time. Zircon U–Pb dating and Hf isotope analyses of granitic rocks collected from the Karakoram terrane and Ladakh batholith have been conducted to constrain these geological processes. Undeformed Ladakh batholith granodiorite...
The Late Paleozoic to Early Mesozoic mafic–ultramafic complexes from the northern North China Block (NCB) are used to constrain the isotopic composition and evolution of mantle reservoirs during different tectonic stages prior to the initiation of lithosphere destruction in the Late Mesozoic. Zircon U–Pb ages show that emplacement of the mafic–ultramafic complexes occurred in at least three stages:...
Zircon grains from modern and ancient drainages of the Gawler Craton, South Australia have been analysed to define the relative contributions of juvenile sources and recycled crust to magmatic activity as a function of time, and to constrain the role of mantle inputs during the Proterozoic rejuvenation of the Archean Gawler Craton. The integration of Hf-isotope data with U–Pb age spectra shows that...
Kyanite and zoisite eclogites from the Limousin area in the Variscan French Massif Central (FMC) have been formed by deep subduction to 100km depth at peak pressure–temperature conditions around 660°C and 2.9GPa. They belong to a thin tectonic unit comprising ophiolitic bodies devoid of HP-UHP markers and forming a transported suture zone now separating the two main lithotectonic units of the FMC...
This paper presents a set of new SHRIMP zircon U–Pb geochronological, elemental and Sr–Nd–Pb isotopic data for the Wusu and Yaxuanqiao basaltic rocks (the Mojiang area) along the Ailaoshan tectonic zone. The Wusu basaltic sequence is dominated by SiO 2 -poor, MgO- and TiO 2 -rich basalts with a major mineral assemblage of plagioclase+clinopyroxene. These rocks gave a SHRIMP zircon...
Hydrothermally altered rocks are products of fluid–rock interactions, and typically preserve numerous quartz veins that formed as chemical precipitates from fluids that fill up cracks. Thus, quartz veins are the record of the fluid system that involved fracture flow in the direction of changing temperature or pressure. In order to decipher the fluid activity in the Sulu ultrahigh-pressure (UHP) terrane...
During the Late Mesozoic, extensive magmatism and associated ore deposits were developed in the southeast Hubei Province, Middle–Lower Yangtze River metallogenic belt (MLYRB), East China. To understand the petrogenesis of the intrusions in the area, we performed in situ zircon U–Pb and Hf isotopic analyses on 14 samples from the Fengshangdong stock, and from the Echeng, Tieshan, Wangbaoshan–Jinshandian...
In-situ zircon U–Pb ages, Hf isotopic compositions and whole rock geochemical and Sr–Nd isotopic compositions are presented for three Mesozoic syenitic–monzonitic intrusions from Shanxi province, central North China Craton. Zircons from these intrusions all show core–rim structures in that the oscillatory rims recorded their intrusive ages, whereas the cores are interpreted as xenocrysts. The U–Pb...
The Jinshajiang suture zone, located in the eastern part of the Tethyan tectonic domain, is noticeable for a large-scale distribution of Late Jurassic to Triassic granitoids. These granitoids were genetically related to the evolution of the Paleo-Tethys Ocean. Beiwu, Linong and Lunong granitoids occur in the middle zone of the Jinshajiang Suture Zone, and possess similar geochemical features, indicating...
The Late Carboniferous to Permian marks an important phase of terrane amalgamation through accretion–collision in the Central Asian Orogenic Belt (CAOB). The Tianshan Belt forms part of this sequence, where the post-collisional event generated an E–W trending bimodal volcanic zone that extends for ca. 500km from the southern Bogda Mt. to the easternmost Tianshan Belt. Here we report the petrology,...
During geological investigations conducted over the past several years, the authors found a group of A-type granites in the middle segment of the Bangonghu–Nujiang suture on the Tibetan plateau. These granitic plutons occur as stocks with exposed areas of less than 1km 2 and lithologically include biotite granite and granodiorite porphyry, which had intruded into Cretaceous sedimentary rocks...
Zircon U–Pb ages and Hf isotopic compositions of Mesozoic magmatic rocks from the Chizhou Area are systematically investigated to reveal the tectonic setting of magmatism and their relationship with Cu–Au mineralization in the Lower Yangtze River Belt, southeastern China. The samples cover nearly all types of magmatic rocks in a 30×50km 2 region, including 6 granite porphyries, 6 dacites and...
In the eastern South China Block (SCB), the presence of middle Paleozoic volcanics and mafic rocks is poor in spite of the extensive occurrence of granites in response to the synchronous (Kwangsian) intracontinental orogen event. The nature of the lithosphere and its associated orogenic process are poorly known for such a major orogen. In this paper, a set of new U–Pb zircon geochronological, elemental...
The Gejiu tin district in western Cathaysia block comprises a series of igneous rocks including equigranular and porphyritic granites, gabbro and nepheline syenite. Systematic SHRIMP or LA-ICP-MS zircon U–Pb analyses of 15 representative samples from various phases of the Gejiu complex yielded Late Cretaceous ages of 78–85Ma. Based on their mineralogical, geochemical and Sr–Nd–Hf isotope characteristics,...
The Dunhuang Block, located in the eastern Tarim Craton, widely exposes Precambrian TTG gneisses and metamorphosed supracrustal rocks. A suite of metasedimentary rocks of the Dunhuang Group in the Hongliuxia area on the eastern margin of the Tarim Craton are characterized by moderate contents of quartz, plagioclase, and biotite, with minor amounts of garnet or kyanite, most of which have experienced...
Early Mesozoic igneous rocks are rarely found in the area east of Wuyi Mountain, southeast China. Our study of petrography and geochronology reveals that the Dayinchang (DYC hereafter) granitic pluton and Xiamao diabases are Early Mesozoic igneous rocks. The DYC pluton can be divided into two parts: the western and eastern parts. Zircon U-Pb dating revealed that the crystallization age of the western...
The Erhongwa mafic–ultramafic intrusion is located in the southern margin of the Central Asian Orogenic Belt in northern Xinjiang where many early-Permian mafic–ultramafic intrusions host important Ni–Cu sulfide deposits. In this paper we report zircon U–Pb age, olivine chemistry and integrated whole-rock chemical and isotopic compositions for the Erhongwa mafic–ultramafic intrusion. This intrusion...
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...
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