Metamorfismo

Journal of Asian Earth Sciences 49 (2012) 214–233

Contents lists available at SciVerse ScienceDirect

Journal of Asian Earth Sciences
journal homepage: www.elsevier.com/locate/jseaes

Zircon U–Pb ages of the metamorphic supracrustal rocks of the Xinghuadukou Group and granitic complexes in the Argun massif of the northern Great Hinggan Range, NE China, and their tectonic implicationsGuang Wu a,b,⇑, Yuchuan Chen c, Yanjing Chen d, Qingtao Zeng e
a

Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, PR China Henan Lingbao Jinyuan Mining Limited Liability Company, Lingbao 472500, PR China Chinese Academy of Geological Sciences, Beijing 100037, PR China d Key Laboratory of Orogen and Crust Evolution, Ministry of Education, Peking University,Beijing 100871, PR China e Center for Exploration Targeting, The School of Earth and Environment Sciences, University of Western Australia, Perth, WA 6009, Australia
b c

a r t i c l e

i n f o

a b s t r a c t
The basement of the Argun massif in the northern Great Hinggan Range consists of the metamorphic supracrustal rocks of the Xinghuadukou Group and associated granitic complexes. Themetamorphic supracrustal rocks were previously interpreted as Paleoproterozoic, while the granitic complexes were considered Mesoproterozoic in age. This paper presents new zircon LA-MC-ICP-MS U–Pb ages of biotite-plagioclase leptynite and biotite schist from the Xinghuadukou Group in the Lulin Forest area, Heilongjiang Province; zircon SHRIMP U–Pb ages of biotite-plagioclase gneiss from theXinghuadukou Group in Lulin Forest; and quartz diorite and monzogranite from the granitic complexes in Mohe County, Heilongjiang Province. New geochronological data from the three metasedimentary rock samples of the Xinghuadukou Group can be preliminarily divided into five groups: (1) 2017–2765 Ma, (2) 1736–1942 Ma, (3) 1359–1610 Ma, (4) 749–1239 Ma, and (5) 448–716 Ma. Except for the zircons of the448–716 Ma group belonging to a metamorphic origin, the other age groups had the youngest age of 749 ± 17 Ma, indicating that the Xinghuadukou Group formed during the Neoproterozoic era (at least 1850 Ma), and the latter as Mesoproterozoic in age (Inner Mongolian Autonomous Region Bureau of Geology and Mineral Resource (IBGM), 1991; Heilongjiang Bureau of Geology and Mineral Resource (HBGM), 1993; Sunet al., 2002). Recent geochronological studies (Wilde et al., 2000, 2003; Wu et al., 2001a; Miao et al., 2004, 2007; Sorokin et al., 2004a,b; Ge et al., 2005, 2007)

G. Wu et al. / Journal of Asian Earth Sciences 49 (2012) 214–233

215

Fig. 1. Simplified geological map of the northern Great Hinggan Range, showing geotectonic units (geotectonic map modified from Li et al. (2004); regionalgeological map modified from Miao et al. (2007)). AG, Argun massif; BJ, Bureya–Jiamusi composite massif; CM, Central Mongolia massif; JG, Junggar-Tuha-Gobi Tianshan massif; KHOB, Karafuto-Hokkaido orogenic belt; KK, Khanka massif; MOSZ, Mongolia-Okhotsk suture zone; NC, North China craton; NSOB, Nadanhada-Sikhote orogenic belt; SB, Siberia craton; SJSZ, Solonker-Jilin suture zone; TSGSZ, Tianshan-SouthMongolia-Great Hinggan Range suture zone; VS, Vitim-Stanovoy massif; TV, Tuva massif.

have shown that many Precambrian massifs in the Mongolia-Hinggan orogenic belt, such as the Jiamusi, Songnen and Argun massifs, were not as old as previously considered. It was argued that the Xinghuadukou Group was no older than the Late Mesoproterozoic (Wu et al., 2001b; Miao et al., 2004, 2007) and thatthese granitic complexes mainly emplaced between 460 Ma and 527 Ma (Wilde et al., 2000, 2003; Sorokin et al., 2004a,b; Ge et al., 2005, 2007; Wu et al., 2005). Therefore, the formation age and tectonic

evolution of the basement of the Argun massif are still debated and need to be determined accurately. In this paper, we report zircon LA-MC-ICP-MS (Laser Ablation Multi-Collector Inductively...