A Jurassic garnet-bearing granitic pluton from NE China showing tetrad REE patterns

TL;DR: In this paper, the authors used the ICP-MS zircon U-Pb ages and geochemical data for the Mesozoic volcanic rocks in northeast China, with the aim of determining the tectonic settings of the volcanism and constraining the timing of the overprinting and transformations between the Paleo-Asian Ocean, Mongol-Okhotsk, and circum-Pacific Tectonic regimes.

TL;DR: In this article, the authors proposed that granites are an important sign indicating compositional maturity of the continental crust, and they are also closely related to the rare-elemental (metal) mineralization of W, Sn, Nb, Ta, Li, Be, Rb, Cs, REEs, etc.

TL;DR: In this article, the ages of 43 volcanic rocks from the four recognized formations (Manketouebo, Manitu, Baiyingaolao and Meiletu) in the southern Great Xing'an Range are presented.

TL;DR: The postcollisional magmatism of the Junggar Terrane is characterized by intrusion of large amounts of granitoids and minor basic/ultrabasic rocks as mentioned in this paper.

Abstract: Granites and related volcanic rocks of the Lachlan Fold Belt can be grouped into suites using chemical and petrographic data. The distinctive characteristics of suites reflect source-rock features. The first-order subdivision within the suites is between those derived from igneous and from sedimentary source rocks, the I- and S-types. Differences between the two types of source rocks and their derived granites are due to the sedimentary source material having been previously weathered at the Earth's surface. Chemically, the S-type granites are lower in Na, Ca, Sr and Fe3+/Fe2+, and higher in Cr and Ni. As a consequence, the S-types are always peraluminous and contain Al-rich minerals. A little over 50% of the I-type granites are metaluminous and these more mafic rocks contain hornblende. In the absence of associated mafic rocks, the more felsic and slightly peraluminous I-type granites may be difficult to distinguish from felsic S-type granites. This overlap in composition is to be expected and results from the restricted chemical composition of the lowest temperature felsic melts. The compositions of more mafic I- and S-type granites diverge, as a result of the incorporation of more mafic components from the source, either as restite or a component of higher temperature melt. There is no overlap in composition between the most mafic I- and S-type granites, whose compositions are closest to those of their respective source rocks. Likewise, the enclaves present in the more mafic granites have compositions reflecting those of their host rocks, and probably in most cases, the source rocks.S-type granites have higher δ18O values and more evolved Sr and Nd isotopic compositions, although the radiogenic isotope compositions overlap with I-types. Although the isotopic compositions lie close to a mixing curve, it is thought that the amount of mixing in the source rocks was restricted, and occurred prior to partial melting. I-type granites are thought to have been derived from deep crust formed by underplating and thus are infracrustal, in contrast to the supracrustal S-type source rocks.Crystallisation of feldspars from felsic granite melts leads to distinctive changes in the trace element compositions of more evolved I- and S-type granites. Most notably, P increases in abundance with fractionation of crystals from the more strongly peraluminous S-type felsic melts, while it decreases in abundance in the analogous, but weakly peraluminous, I-type melts.

TL;DR: In this paper, the authors investigated the properties of trace elements in aqueous systems and showed that trace element fractionation is not solely dependent on ionic charge and radius, but is also controlled by the electron configuration and the type of complexing ligand, since the latter two determine the character of the chemical bonding in the various complexes.

TL;DR: A-type granites are widely distributed in northeastern China (NE China). They were emplaced during three major episodes (the Permian, late Triassic to early Jurassic, and early Cretaceous) and evolved in different tectonic regimes.