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A compilation of magmatic ages from the Mesozoic South China Block suggests a number of “magmatic quiescence” periods at ca. 205–195Ma, ca. 150–140Ma and ca. 125–115Ma, casting doubt on tectonic models that suggest ongoing Andean-type subduction along the South China continental margin. However, SIMS U-Pb analyses on two detrital zircon samples from the Cretaceous Lumuwan Formation on Hainan Island,...
Charnockites are Opx-bearing igneous rocks commonly found in high-grade metamorphic terranes. Despite being volumetrically minor, they show a wide range in both bulk geochemistry and intensive parameters. They form a characteristic component of the AMCG (anorthosite–mangerite–charnockite–granite) suite, but their association with typical S-type granites is less well-known. The Darongshan S-type granitic...
Nephrite is a kind of valuable jade which forms during metamorphism under greenschist facies conditions. Most investigations focus on the genesis of nephrite, however, the formation age of nephrite remains poorly constrained due to the lack of suitable dating methods. In this paper, the petrological, chemical characteristics, and mineral inclusions of nephrite collected from Luanchuan, Henan, China...
Knowledge of the age and timing of ophiolite sequences is essential for understanding the mechanisms of plate tectonics. The ophiolites in the Schistes Lustrés and the Upper nappes of Alpine Corsica represent remnants of the Liguria–Piemonte ocean basin that formed as a branch of the Central Atlantic basin during the opening of the Mesozoic Western Alpine Tethys. Despite numerous isotopic and paleontological...
Kashmar granitoids outcrop for ~100km along the south flank of the Sabzevar ophiolite (NE Iran) and consist of granodiorite and monzogranite along with subordinate quartz monzonite, syenogranite and aplitic dikes. These granitoids intruded Early to Middle Eocene high-K volcanic rocks and can spatially be grouped into eastern and western granitoids. Five samples of granite have identical zircon U-Pb...
Carboniferous igneous rocks constitute volumetrically minor components of Iranian crust but preserve important information about the magmatic and tectonic history of SW Asia. Ghushchi granites and gabbronorites in NW Iran comprise a bimodal magmatic suite that intruded Ediacaran–Cambrian gneiss and are good representatives of carboniferous igneous activity. Precise SIMS U–Pb zircon ages indicate that...
Perovskite-bearing harzburgites occur in a “mélange” type blueschist-bearing accretionary wedge complex of the Inner Western Carpathians Meliata Unit in Slovakia. Although dark rounded, slightly hydrated relic “cores” of harzburgite boulders are perovskite-free, perovskite (Prv) occurrence in the surrounding serpentinites and rodingites enabled dating of hydration, resulting in two metamorphic–metasomatic...
Assessment of the synchroneity between the Siberian Traps and the Permo-Triassic boundary (PTB) mass extinction has led to the proposition that the Siberian flood volcanism was responsible for the severest biotic crisis in the Phanerozoic. However, recent studies suggest that the Siberian Traps may have postdated the main extinction horizon. In this paper, we demonstrate, using stratigraphy, a time...
Silicic igneous provinces have important implications for geodynamic processes. In this study, we show that the predominantly Early Permian (ca. 280Ma) granitoids in the Alxa Block correspond to an important silicic igneous province with areal distribution in Northwest (NW) China. We present zircon U–Pb age and Hf–O isotopic, and whole-rock geochemical and Sr–Nd isotopic data for the newly identified...
The Early Permian Tarim Large Igneous Province (LIP) in northwestern China contains a large area of silicic volcanics (~48,000km 2 ) which are spatially and temporally associated with mafic–ultramafic rocks. In order to understand the behavior of crust above a mantle plume, selected rhyolitic samples are investigated in terms of U–Pb zircon dating, geochemical and isotopic analyses. The Tarim...
Zircon is widely used in geochronology and as an isotopic tracer in igneous processes. However, the use of isotopic data obtained from zircon requires evaluating of processes that might compromise the robustness of its isotopic systems. In this study we have assessed how different U contents and degrees of metamictization have affected the SIMS U-Pb and oxygen-isotope signatures of zircon-quartz pairs...
The Qieganbulake ultramafic–carbonatite complex located within the northeastern margin of the Tarim Block of Northwest China hosts the world's second largest vermiculite deposit. Field observations, radiometric dating results and Sr–Nd–Hf isotopes reveal that the parental magmas of the carbonatite and ultramafic rocks are cogenetic and formed synchronously at ~810Ma. They are characterized by unusually...
The Chenaillet Ophiolite is one of the best-preserved remnants of the Piemont-Liguria oceanic basin, a branch of the Central Atlantic that opened during the separation of Adria/Africa from Europe. Despite numerous studies of structure, petrology, geochemistry and isotope geochronology, the timing and genesis of various magmatic rocks within the Chenaillet Ophiolite are still controversial. We provide...
Understanding the processes responsible for the intra-plate early Paleozoic Wuyi–Yunkai orogeny (>460Ma to 420–415Ma) in the South China Block (SCB) is important for deducing the interactions of this block with other continents at that time, as well as the tectonic evolution of East Asia. One salient feature of the orogen is that despite the wide occurrence of syn- to late-orogenic (440Ma to 420–415Ma)...
Mesozoic magmatism is extensively developed in eastern China along the eastern Asian continental margin, but the geochronological framework is not well understood for each area. In this study, seventy-eight samples were collected from the Mesozoic igneous rocks in south Anhui Province, east-central China, in order to precisely constrain their formation ages and contributions to crustal growth. Zircon...
We report SIMS U–Pb zircon, elemental and Nd–Sr–Pb isotopic data for the volcanic rocks and their subvolcanic units from the Xiemisitai Mountains in the West Junggar Region (Xinjiang, China), aiming to determine their ages, source regions and tectonic setting. Zircon U–Pb dating results of the volcanic rocks (422.5±1.9Ma–411.2±2.9Ma) indicate that the volcanic strata occurred in the Xiemisitai Mountains...
The West Junggar, northwestern China, is located in the southwest of the Central Asian Orogenic Belt (CAOB) and consists of Paleozoic ophiolitic mélanges, arcs and accretionary complexes. The Mayile Mountain ultramafic–mafic mélange in the southern West Junggar is the northeastern part of the Mayile ophiolitic mélange. The Mayile Mountain mélange is represented by a ca. 30km long, 5km wide, north–northeast-striking...
The debate on the Mesozoic tectonics of the South China Block (SCB), featuring a broad orogenic belt and a large continental magmatic province, has been rejuvenated in the past years. There are a number of competing tectonic models, each predicting different time, space, and compositional evolutional trends for the Mesozoic igneous rocks, including sporadic basalts. In this paper, we report high precision...
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