Zircon SHRIMP U-Pb ages of the “Xinghuadukou Group” in Hanjiayuanzi and Xinlin areas and the “Zhalantun Group” in Inner Mongolia, Da Hinggan Mountains
Tóm tắt
A report is presented of SHRIMP zircon U-Pb dating data of meta-igneous and meta-sedimentary rocks of the Xinghuadukou Group (Xinlin-Hanjiayuanzi area, Heilongjiang Province) and meta-volcanic rocks of the Zhalantun Group (Zhalantun district, Inner Mongolia). The SHRIMP analyses show that the meta-igneous rocks from the Xinghuadukou Group formed at 506±10–547±46 Ma, belonging to Early-Middle Precambrian, whereas the meta-sedimentary rocks yielded detrital zircons, with ages of 1.0–1.2, 1.6–1.8 and 2.5–2.6 Ga, indicative of deposition age at least <1.0 Ga. Meta-basic volcanic rocks from the Zhalantun Group have a formation age of 506±3 Ma. These data suggest that both the Xinghuadukou and Zhalantun Groups formed during Cambrian and/or Neoproterozoic time, rather than Paleoproterozoic time as previously thought. Early Precambrian inherited zircons in the meta-igneous rocks and numerous Precambrian detrital zircons in the meta-sedimentary rocks imply that these rocks were formed proximal to older crust. It is inferred that the Xinghuadukou and Zhalantun Groups represent Cambrian and/or Neoproterozoic volcano-sedimentary sequences formed in an active continental margin setting.
Tài liệu tham khảo
Geology and Mineral Resource Bureau of Heilongjiang Province. Regional Geology of Heilongjiang Province (in Chinese). Beijing: Geological Publishing House, 1993
Geology and Mineral Resource Bureau of Inner Mongolian Autonomous Region. Regional Geology of Inner Mongolian Autonomous Region (in Chinese). Beijing: Geological Publishing House, 1991
Jiang C C. Pre-Sinian systems in the northwestern Lesser Xing’an Range-Geology of the Heilongjiang River and its adjacent areas (in Chinese). Beijing: Geological Publishing House, 1963
Zhang X Z, Sklyarov E V. Tectonic significance of blueschist belts in Northeast China and its adjacent regions. In: Selected Papers of Geological Researches of the Changchun Geological Institute (in Chinese). Beijing: Seismic Press, 1992. 99–106
Ye H W, Zhang X Z, Zhou Y W. Lithospheric framework and evolution of the Manzhouli-Suifenhe geoscience transect based on the characteristics of blue-schist and ophiolite. In: M-SGT Geologic Group, ed. Geological Study on the Lithospheric Framework and Evolution of the Manzhouli-Suifenhe Geoscience Transect, China (in Chinese). Beijing: Seismic Press, 1994. 73–83
Ye M, Zhang S H, Wu F Y. Tectonic units and evolution along the Manzhouli-Suifenhe geo-profile. J Changchun Univ Technol (in Chinese), 1994, 24(2): 241–245
Zhao C J, Peng Y J, Dang Z X, et al. Tectonic Framework and Crustal Evolution of the Eastern Jilin and Heilongjiang Provinces (in Chinese). Shenyang: Liaoning University Press, 1996
Li C Y. Explanation Book to Asian Tectonic Map on a 1: 8000000 Scale (in Chinese). Beijing: Geological Publishing House, 1982
Li J Y. Some new ideas on tectonics of NE China and its neighboring areas. Geol Rev (in Chinese), 1998, 44(4): 339–347
Biao S H, Li Y C, He X H, et al. Geochemistry of the Xinghuadukou Group in Lulin area, Tahe, Heilongjiang. Reg Geol China (in Chinese), 1999, 18(1): 28–33
Miao L C, Fan W M, Zhang F Q, et al. Zircon SHRIMP U-Pb geochronology of the Xinkailing-Kele complex in northwestern Lesser Xing’an Range and its significance. Chin Sci Bull, 2004, 49(2): 201–209
Ge W C, Wu F Y, Zhou C Y, et al. Emplacement age of the Tahe granite and its constraints on the tectonic nature of the Ergun block in the northern part of the Da Xinggan Range. Chin Sci Bull, 2005, 50(18): 2097–2105
Zhou C Y, Wu F Y, Ge W C, et al. Age, geochemistry and genesis of the Tahe cumulative gabbro in the northern Da Hinggan Mountains. Acta Petrol Sin (in Chinese), 2005, 21(3): 763–775
Compston W, Williams I S, Mayer C. U-Pb geochronology of zircons from Lunar Breccia 73217 using a Sensitive High Resolution Ion Microprobe. Proc. XIV Lunar Planetary Science Conference. J Geophys Res, 1984, 89(suppl): B525–B534
Compston W, Williams I S, Kirschvink J L, et al. Zircon U-Pb ages for the Early Cambrian time scale. J Geol Soc London, 1992, 149: 171–184
Williams I S, Claesson S. Isotopic evidence for the Precambrian provenance and Caledonian metamorphism of high-grade paragneisses from the Deve Nappes, Scandinavian Caledonides: II: Ion microprobe zircon U-Th-Pb. Contrib Mineral Petrol, 1987, 97: 205–217
Jian P, Liu D Y, Sun X M. SRHIMP dating of Carboniferous Jinshajiang ophiolite in western Yunnan and Sichuan: geochronological constraints on the evolution of the Paleo-Teths oceanic crust. Acta Geol Sin (in Chinese), 2003, 77(2): 217–228
Wu F Y, Sun D Y, Li H M. Zircon U-Pb ages of basement rocks beneath the Songliao Basin, NE China. Chin Sci Bull, 2000, 45(16): 1514–1518
Wu F Y, Sun D Y, Li H M, et al. The nature of basement beneath the Songliao Basin in NE China: Geochemical and isotopic constraints. Phys Chem Earth (A), 2001, 26(9–10): 793–803
Sun D Y, Wu F Y, Li H M, et al. Emplacement age of the postorogenic A-type granites in northwestern Lesser Xing’an Ranges, and its relationship to the eastward extension of Suolun-shan-Hegenshan-Zhalaite collisional suture zone. Chin Sci Bull, 2001, 46(5): 427–432
Wu F Y, Sun D Y, Li H M, et al. A-type granites in northeastern China: age and geochemical constraints on their petrogenesis. Chem Geol, 2002, 187(1–2): 143–173