Neoarchean magmatic arc in the Western Liaoning Province, northern North China Craton: Geochemical and isotopic constraints from sanukitoids and associated granitoids

Abstract

The Neoarchean Western Liaoning basement terranes in the northern part of North China Craton chiefly consist of tholeiitic basalts in the north, TTG gneisses and metavolcanic rocks in the northwest, and K-rich granitoids in the southeast. In the southeastern zone, porphyritic monzodioritic-quartz monzodioritic-granodioritic-monzogranitic (MQGM) gneisses are the major lithological assemblage, and locally contain minor xenoliths of TTG gneisses. Based on the major mafic mineral phases, the porphyritic MQGM gneisses can be divided into amphibole-dominated and biotite-dominated groups. Zircon U-Pb isotopic dating indicates that the amphibole-dominated MQGM gneisses, biotite-dominated MQGM gneisses, and tonalitic gneiss xenolith were emplaced during 2546-2529 Ma, 2546-2531 Ma, and at 2563 Ma, respectively. The 2563 Ma tonalitic gneiss xenolith displays geochemical affinities to high-SiO 2 adakites, and may be formed by the partial melting of descending oceanic slabs, with the melt contaminated by mantle peridotite. The amphibole-dominated MQGM gneisses are geochemically analogous to sanukitoids, and their magmatic precursors were formed by partial melting of lithospheric mantle, which was metasomatized by dehydration fluids and melts derived from subducted oceanic sediments and slabs. The magmatic precursors of the biotite-dominated MQGM gneisses were generated by the partial melting of medium-K to high-K mafic rocks at medium pressures. Integrated with previous studies on supracrustal sequences and granitoids in Western Liaoning Province, the Neoarchean lithological assemblages in the southeastern zone were most likely formed in an active continental margin setting.

Products of an Early Cretaceous extensional mechanism in the central Great Xing'an Range: Felsic plutons in the Zhalantun area and their parental magma compositions and diagenetic processes

“…Besides, with respect to intermediate-acid magmas, zircons are preferred to crystallize early, and therefore, provide better limits on temperatures of relatively pristine magmas(Zeng, Xu, Huang, Li, & Chen, 2020). Taken together, we prefer to interpret T Ti-Zrn values of $749 and $760 C as the best estimates for crystallization temperatures of GM and quartz monzodiorite, respectively, both of which are consistent with the temperature of the water-saturated melting of granitoid rocks (<803 C,Fu et al, 2018;L. Gao et al, 2018;Watson & Harrison, 1983) and imply fluid-present magmatic origins.…”

Reworking of Eoarchean to Mesoarchean Continental Crust in the Anshan–Benxi Area, North China Craton—Evidence from Lianshanguan ca. 2.5 Ga Syenogranites

“…In Northern Liaoning area (north of the Anshan-Benxi area) and Western Liaoning-Eastern Hebei area (west of the Anshan-Benxi area) (Figure 7A), there are abundant late Neoarchean non-tonalite-trondhjemite-granodiorite (non-TTG) granitoids reported [94][95][96][97][98][99][100]. Recently, Wang et al [94] summarized granitoids in the Suizhong granitic belt (which spans the Western Liaoning-Eastern Hebei area) and divided the non-TTG granitoids into two groups, namely sanukitoid-like granites and potassic granites.…”

Metamorphic evolution of the Sittampundi Layered Complex, India, during the Archaean–Proterozoic boundary: insight from pseudosection modelling and zircon U–Pb SHRIMP geochronology

“…The existence of subduction during the Archaean-Proterozoic transition is supported not only by granulite-facies metamorphism but also by the presence of arc-related Neoarchaean granitoids and paired metamorphic belt (Brown, 2010). In the Siziwangqi area of central Inner Mongolia, an arc-related granitoid intruded at c. 2520-2440 Ma (Chen et al 2017a, b), and in the southern part of eastern Hebei Province and western Liaoning Province, North China Craton, medium-grained monzogranitic-syenogranitic gneisses were emplaced during c. 2527-2511 Ma in a backarc basin tectonic setting (Fu et al 2017). In southern Jilin Province, a Neoarchaean subduction-related Andean-type active continental margin existed along the northern margin of the North China Craton and was associated with two major phases of subduction-related igneous activity at c. 2700 Ma and c. 2600-2500 Ma (Guo et al 2017).…”