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Spatially associated A- and I- type granites and mafic dyke rocks from the Jiuhuashan region (South China) have been geochemically studied with a special emphasis on their halogen (F, Cl, Br, I) contents to better understand the role of halogens during their genesis. The A-type granites and mafic dyke rocks (125–130Ma) intruded later than the I-type rocks (140–143Ma) and whole-rock Nb/Ta ratios increase...
Many Late Triassic granitic plutons are present in the eastern Yidun arc belt (EYAB), and seven have been investigated in this study. From west to east, they are: the Sucuoma (235±2Ma), Ajisenduo (224±2Ma), Jiaduocuo (218±1Ma), Cuojiaoma (219±1Ma), Maxionggou (225±2Ma), Dongcuo (222±3Ma) and Daocheng (220±2Ma) plutons. Most of the plutons have granitic compositions and contain high SiO2, Al2O3 and...
This paper presents geochronological, mineralogical, geochemical, and Sr-Nd isotopic data for recently identified Upper Triassic appinite dyke swarms in the East Kunlun orogenic belt (EKOB), northern Tibetan Plateau. Zircon U-Pb isotopic analyses using SHRIMP and LA-ICP-MS techniques yield 206Pb/238U ages of 226.1±1.9Ma and 226.4±3.5Ma, which can be interpreted as the crystallization ages of the appinite...
An integrated study of the geochronology, mineralogy, geochemistry and Sr–Nd isotope compositions of the upper Permian Yushu mafic rocks in the central Tibetan Plateau (CTP) was conducted to evaluate the interaction between the Emeishan mantle plume and the Paleo-Tethyan subduction system. These mafic rocks can be geochemically subdivided into three groups. Group 1 rocks yielded a weighted mean 206...
Cenozoic mafic rocks in Jiangsu and Anhui Provinces, east-central China are chiefly basanites and alkali olivine basalts with subordinate tholeiites, which were erupted in three stages; Paleogene, Neogene and Quaternary. The rocks become increasingly alkaline as they become younger. On a primitive mantle-normalized multi-element plot, these lavas exhibit typical OIB-like trace element patterns, including...
Although numerous Paleo-Tethyan ophiolites with mid-oceanic ridge basalts (MORB) and/or oceanic-island basalt (OIB) affinities have been reported in the central Tibetan Plateau (CTP), the origin and tectonic nature of these ophiolites are not well understood. The petrogenesis, mantle sources and geodynamic setting of the mafic rocks from these ophiolites are unclear, which is the main reason for this...
The Triassic Yidun arc belt (YAB) lies between the Jinshajiang suture zone to the west and the Garzê-Litang suture zone to the east, Eastern Tibetan Plateau. To study the YAB can not only help us to better understand the evolutionary history of the Garzê-Litang Ocean but can also provide some important information to constrain the evolution of the eastern Paleo-Tethys. In this paper, the geochronological...
A comprehensive study on zircon U-Pb age dating, whole-rock geochemistry and Sr-Nd isotope data has been conducted on the mafic rocks of the Xiazhuang uranium ore district and adjacent regions in South China. Based on field work and petrographic features, three rock types (the Kuzhukeng gabbro, the WNW-trending dolerite dykes and the NNE-trending lamprophyre dykes) are distinguished. Early Jurassic...
The Mesozoic geology in SE China is characterized by widespread Jurassic–Cretaceous magmatism. There appears, however, an episode of “magmatic quiescence” at ca. 130–110Ma in terms of increasing high-precision isotopic age data. The causes and regional tectonic significance of this magmatic quiescence are unclear. In this paper, we report integrated in situ U–Pb, Hf and O isotope analyses of zircons...
Cenozoic continental basalts from Zhejiang Province, southeast China are tholeiitic to weakly alkalic in composition, with moderate MgO contents (6–11wt.%) and an average Mg# of 62. They display typical OIB-like trace element features, including enrichment in most incompatible elements, both LILE and LREE, and negative K, Pb, Zr, Hf anomalies. In particular, they are characterized by high Fe/Mn (73±5),...
Low- 18 O felsic igneous rocks (with δ 18 O values of <5‰) are a group of volumetrically minor rocks that in their genesis require involvement of oxygen from seawater or meteoric water at high temperature. Most low- 18 O felsic rocks are reported in caldera or rift settings, where high-temperature hydrothermal exchange of surface waters with source rocks readily imprints...
We present major and trace elemental geochemical data, Sr–Nd–Hf isotopes and zircon U–Pb ages for igneous rocks of the Mufushan complex (~2400km 2 outcrop area) in South China. The complex intruded episodically from late Jurassic (ca.154Ma) to early Cretaceous (ca. 146Ma) with a compositional evolution from diorite through granodiorite and biotite-bearing monzogranite to two-mica leucogranite...
The NWW-striking Qinling Orogen formed in the Triassic by collision between the North China and Yangtze Cratons. Triassic granitoid intrusions, mostly middle- to high-K, calc-alkaline, are widespread in this orogen, but contemporaneous intrusions are rare in the southern margin of the North China Craton, an area commonly considered as the hinterland belt of the orogen. In this paper, we report zircon...
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