figshare
Browse
1/1
2 files

Late Paleocene–early Eocene granitoids in the Jiamusi Massif, NE China: Zircon U–Pb ages, geochemistry, and tectonic implications

dataset
posted on 2018-02-28, 06:37 authored by Peng-Chuan Li, Zheng-Hong Liu, Shi-Chao Li, Qing-Ying Zhao, Qiang Shi, Chang-Hai Li, Xu-Hai Yang

Northeast (NE) China is characterized by large areas of Mesozoic and Paleozoic granitoids, whereas Cenozoic granitoids are scarce. This paper reports LA-ICP-MS zircon U–Pb ages and whole-rock geochemical data for late Paleocene–early Eocene granitoids from the Jiamusi Massif, NE China, in order to determine their petrogenesis and tectonic implications. Geochronological data indicate that the granodiorite and dioritic porphyry from the Wudingshan pluton formed at 51.5 ± 0.3 Ma and 56.3 ± 0.8 Ma, respectively. The biotite–quartz diorite, biotite granodiorite, and dioritic porphyry have high SiO2 (68.38–70.06 wt.%), Al2O3 (15.34–15.79 wt.%), and Na2O (3.96–4.49 wt.%) contents, low MgO contents (1.10–1.26 wt.%), A/CNK ratios of 0.99–1.11, and are classified as medium- to high-K calc-alkaline and weakly peraluminous I-type granitoids. They are enriched in LREEs and LILEs, and depleted in HFSEs, with Nb/Ta ratios of 10.4–15.0. Moreover, they have negative Nb–Ta–Ti anomalies, indicating that they were derived from continental crust. Combining with the previously published isotopic data and regional geological results, we suggest that the late Paleocene–early Eocene granitoids (56–52 Ma) were probably derived from partial melting of juvenile lower crust, and formed in an active continental margin setting, possibly related to subduction slab rollback of the Paleo-Pacific Plate.

Funding

This work was financially supported by the National Natural Science Foundation of China [grant number 41272223] and the China Geological Survey [grant number 12120115001601 and 1212011120973].

History