地质学报2012，Vol.86Issue(5)：775-784,10.
白云鄂博陆缘裂谷系沉积物源与超大型稀土矿床含矿白云岩的成因探讨
Sediment Source of Bayan Obo Marginal Rift and Genesis of Ore-Bearing Dolomite of the Giant REE Deposit
摘要
Abstract
Detrital zircon ages of Jianshan Formation H4 quartz sandstone of Bayan Obo Group record two major tectonic-magmatic events in the northern margin of the North Chian Craton (NCC). One Group of age concentrates in the Late Archean—Early Paleoproterozoic (2379~2596 Ma), and the other in the medium Paleoproterozoic (1761 —1946 Ma). The results are consistent with the zircon ages of basement rocks in the Bayan Obo region. The 207Pb-206Pb isochron age (1649±45 Ma) of the sedimentary carbonate rocks of the Bayan Obo Group may represent its deposition times. The Pb isotope compositions of ore-bearing dolomite marble are quite different from those of the sedimentary carbonate rocks of the Bayan Obo Group. In the Pb isotope composition and tectonic diagram, the ore-bearing dolomite marbles are concentrated near the mantle evolution line and close to depleted mantle end member [(206 Pb/204 Pb)j = 15. 04 ~ 16. 49, (207pb/204pb)i = 15.17~15.28, (208pb/204Pb), = 31. 20 — 36.40 ], but the sedimentary carbonate rocks are distributed near the orogenic evolution line and close to the pelagic sediment end member [(206Pb/204Pb)i = 17. 28~19. 35, (207Pb/204Pb)i = 15. 47~15. 69, (208Pb/204Pb)i = 36. 62~37.12 ].关键词
白云鄂博群/碎屑锆石/含矿白云岩/Pb同位素/U-Pb年龄Key words
detrital zircons ore-bearing dolomite marble/ Pb isotope/ U-Pb isotopic age/ Bayan Obo Group引用本文复制引用
杨奎锋,范宏瑞,胡芳芳,王凯怡..白云鄂博陆缘裂谷系沉积物源与超大型稀土矿床含矿白云岩的成因探讨[J].地质学报,2012,86(5):775-784,10.基金项目
本文为国家自然科学基金项目(编号40902028)资助的成果. （编号40902028）
