3 research outputs found
Supplemental Material: Diachronous subduction, closure of the Proto-Tethys Ocean, and collisional accretion of microcontinents: Insights from the early Paleozoic intermediate-mafic rocks in the Amdo microcontinent of the Tibetan Plateau
Table S1: Summary of age data for the Ediacaran–early Paleozoic magmatic rocks in the East Asian blocks along the northern margin of East Gondwana. Table S2: LA-ICP-MS zircon U-Pb dating results for the igneous rocks from the Amdo microcontinent, central Tibet. Table S3: Hf isotopic data of zircons for the intermediate-mafic rocks from the Amdo microcontinent, central Tibet. Table S4: Whole-rock Sr-Nd isotopic compositions of the meta-basites from the Amdo microcontinent, central Tibet. Table S5: Major- and trace-element compositions of the intermediate-mafic rocks from the Amdo microcontinent, central Tibet. Figure S1: TiO2 (wt%) vs. Th/NbPM, showing partial melting of spinel peridotite source with assimilation of crustal melts.</p
<em>c</em>. 1.85 Ga HP granulite-facies metamorphism in the Dunhuang block of the Tarim Craton, NW China: evidence from U–Pb zircon dating of mafic granulites
<p>Mafic granulites of the Dunhuang block, eastern Tarim Craton, record high-pressure granulite-facies metamorphism followed
by a medium- to low-pressure granulite-facies metamorphic overprint, suggesting a clockwise <em>P–T</em> path and implying an environment of collisional orogenesis. Zircon U–Pb ages of two samples are 1834 ± 12 Ma and 1842 ± 5
Ma. Mineral inclusions in zircon indicate that these ages record the high-pressure granulite-facies event, suggesting that
the Tarim Craton may be related to the <em>c</em>. 1.85 Ga assembly of the Columbia supercontinent. Similar <em>c</em>. 1.85 Ga metamorphism in both the Dunhuang block and the Alxa block of the North China Craton supports their correlation
across the Altyn Tagh fault.
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Two contrasting accretion v. collision orogenies: insights from Early Paleozoic polyphase metamorphism in the Altun–Qilian–North Qaidam orogenic system, NW China
Cathodoluminiscence imagery of zircons revealing <sup>206</sup>Pb/<sup>238</sup>U ages and Th/U
ratios (Table S1) and analysis of biotite from mylonitized paragneiss yielding Ar–Ar plateau and isochron ages (Table S2