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We report in situ O and Hf isotope data of zircon grains from coeval Mesoproterozoic (ca. 1.4 Ga) igneous metamafic (amphibolite) and granitic rocks of the Chinese Central Tianshan microcontinent (CTM) in the southern Central Asian Orogenic Belt (CAOB). Zircon grains from amphibolite have mantle-like δ18OVSMOW values of 4.7–5.6‰ and juvenile Hf isotopic compositions (εHf(t) = 8.4–15.3; TDMC = 1.57–1.22 Ga), whereas those from granitic rocks have δ18OVSMOW values of 5.6–7.0‰ and evolved Hf isotopic compositions (εHf(t) = −1.0–8.2; TDMC = 2.09–1.62 Ga). Zircon O–Hf isotopic compositions of the metamafic and granitic rocks provide evidence for Mesoproterozoic (ca. 1.4 Ga) crustal growth and a substantial Palaeoproterozoic supracrustal component in the CTM. These findings and previous studies, reporting ca. 1.4 Ga magmatic rocks from other microcontinents of the CAOB, suggest that a large belt of Mesoproterozoic (ca. 1.4 Ga) juvenile continental crust formed in a continental terrane, fragments of which now occur over a distance of more than a thousand kilometres in the southern CAOB. [ABSTRACT FROM AUTHOR]

The formation and evolution of the basement rocks in the Tibetan Plateau remain poorly constrained. Here we report petrology, geochemistry, and zircon U-Pb geochronology of orthogneisses, metamafic intrusions, andmetasedimentary rocks from the Amdo basement in central Tibet. The oldest Neoproterozoic (∼820 Ma) orthogneisses show chemical affinity to a volcanic arc setting. These rocks, together with the coeval arc-magmatic rocks, belong to an Andeantype setting traced from the Seychelles, Madagascar, western India, Lhasa, and South China blocks, following the Rodinia supercontinent assembly. The later early Paleozoic (∼500 Ma) bimodal intrusions in Amdo also show an affinity to arc-related igneous rocks and probably formed in an active continental margin associated with the subduction of the Proto-Tethys Ocean beneath the Gondwana supercontinent. In contrast to the adjacent Lhasa and Qiangtang terranes, the Amdo block experienced complex Neoproterozoic and early Paleozoic tectono-thermal events and coherent Jurassic (∼190 Ma) high-pressure granulite-facies metamorphism and associated magmatism, suggesting that the Amdo block was an isolated microcontinent in the Tethyan Ocean and underwent deep subduction before its collision with the Qiangtang or Lhasa terrane. [ABSTRACT FROM AUTHOR]

The unique tetrapyridyl ligand 1,2,4,5-tetra(4-pyridyl)benzene (bztpy) isolated from previous hydrothermal in situmetal ligand reaction is found to exhibit remarkable anion-dependent assembly of a series of novel metal–organic frameworks (MOFs), [Cu2(CN)2(bztpy)] (1), [Cu(SO4)(bztpy)]·1.5H2O (2), [Cu2Br2(bztpy)]·MeCN (3) and [Cu10I10(bztpy)2]·2H2O (4), which were synthesized under hydro/solvothermal conditions. These MOFs were characterized by elemental analysis, IR and single-crystal X-ray diffraction. Compound 1consists of [Cu(CN)]nchains that link the neighbouring ones viatetradentate bztpy bridges to form a corrugated 2D layer. When bztpy is treated with CuSO4, a 3D (3,5)-connected network 2is obtained, in which novel [Cu(bztpy)]nladders are interconnected by sulfate anions μ-bridges. However, Br−and I−anions assist the formation of {Cu2Br2} and {Cu10I10} SBU in the cluster-based metal–organic frameworks 3and 4, respectively, and result in a completely different topology. Compound 3shows a 3D PtS net, while compound 4has a new 3D (4,8)-connected topology. A discussion of the crystal structures, as well as the coordination behaviour of the special tetrapyridyl ligand upon different geometries of the central connecter is provided. In addition, the photoluminescent properties of 1, 3and 4in the solid state at ambient temperature are also investigated. [ABSTRACT FROM AUTHOR]