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In this paper, we report an integrated study of trace element, U-Pb age and Hf isotopic composition of zircons from alkali feldspar granites, granodiorites and diorite enclaves in a recently discovered ring complex at Lianghe in western Yunnan, China. The granitoids showed identical U-Pb ages of 127, 115 and 122 Ma, from felsic to mafic, but had different zircon trace elements and Hf isotopic compositions. Trace element content decreased with a gradual increase in ε Hf (t) values of −9.1 to −5.4, −4.5 to 0, and 3.6 to 6.2, respectively. Results indicate that changes in zircon trace elements generally correlate with changes in Hf isotope signatures within single samples and among various granitoids. These relationships reflect the mixing of felsic and mafic magmas. Evidence indicates that depleted mantle-derived mafic magma underplating caused ancient crustal melting, and then formed large-scale granites in Lianghe during the Early Cretaceous. These granodiorites were formed mainly by the mixing of mafic magma and granitic magma.

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In this paper, we report an integrated study of U‐Pb age and Hf isotope compositions of zircons from biotite plagioclase gneiss at Lianghe in western Yunnan. The zircons preserved inherited core and rim texture. Igneous zircon grains and rims yielded a weighted mean 206Pb/238U age of 120.4±1.7 Ma, their εHf (120 Ma) values were mainly negative ranging from –13.9 to –10.7, with Hf model ages between 1.9 Ga and 2.0 Ga, some zircons had positive εHf (120 Ma) values ranging from 0.2 to 2.1. The inherited cores showed the wide variations in the U‐Pb age of 375–1315 Ma. One of them showed the εHf (506 Ma) value of –4.2, it was similar to the gray gneiss of old crust, which εHf (500 Ma) values were negative ranging from –4.5 to –3.3. Combining geological feature and geochemical data, we concluded that the protolith of biotite plagioclase gneiss was old crust‐derived tonalitic magma during the early Cretaceous.

The Lesser Himalayan Belt in the northern margin of Indian Shield preserves abundant sedimentary and magmatic records related to the assembly and breakup of the Columbia supercontinent. However, the Palaeoproterozoic tectonic history of the northern margin of the Indian Shield and its position in the Columbia supercontinent are still controversial. Based on detailed geological investigations in the Dailekh area of western Nepal, we conducted zircon U-Pb dating and Lu-Hf isotopic analysis for meta-granitoids that intruded into the Lesser Himalayan Crystalline and Metasediments. The Dungeshworl granitic augen gneiss, meta-monzogranite, and tonalitic gneiss yielded crystallization ages of 1,829 ± 12 Ma, 1,856 ± 11 Ma, and 1,852 ± 11 Ma respectively, which demonstrate that the deposition limits of both the Lesser Himalayan Crystalline and Metasediments are the Palaeoproterozoic. Zircon ε Hf (t) values of these meta-granitoids range from À3.99 to +0.18, with corresponding depleted mantle two-stage model (T DM2 ) ages of 2.41-2.62 Ga, indicating that they formed by reworking of Neoarchean to Palaeoproterozoic crust. Synthesizing existing geochronological, petrochemical, and zircon Lu-Hf isotopic data for metamorphic sedimentary and igneous rocks from the entire Lesser Himalayan Belt, we suggest that the Palaeoproterozoic magmatism in the northern margin of Indian Shield may be formed within subduction-related tectonics responded to the assembly of Columbia supercontinent.