DOI: 10.1007/s00531-015-1185-z
论文题名: Timing and nature of the Xinlin–Xiguitu Ocean: constraints from ophiolitic gabbros in the northern Great Xing’an Range, eastern Central Asian Orogenic Belt
作者: Feng Z. ; Liu Y. ; Liu B. ; Wen Q. ; Li W. ; Liu Q.
刊名: International Journal of Earth Sciences
出版年: 2016
卷: 105, 期: 2 起始页码: 491
结束页码: 505
语种: 英语
英文关键词: CAOB
; Gabbro
; Great Xing’an Range
; Hf isotope
; Ophiolitic mélange
; Zircon U–Pb chronology
Scopus关键词: chronology
; gabbro
; hafnium
; melange
; ophiolite
; orogenic belt
; Precambrian
; uranium-lead dating
; zircon
; Central Asia
; Da Hinggan Mountains
英文摘要: Jifeng ophiolitic mélange (ultramafic rocks, meta-basalts and gabbros) crops out in the northern segment of the Great Xing’an Range, the eastern segment of the Central Asian Orogenic Belt, which marks the closure of the Xinlin–Xiguitu Ocean associated with the collision between the Erguna block and Xing’an block. In order to investigate the formation age and magma source of the Jifeng ophiolitic mélange, the gabbros from newly discovered the Jifeng ophiolitic mélange are studied with zircon U–Pb ages, whole-rock geochemistry and zircon Hf isotopes. Zircon U–Pb dating from the ophiolitic gabbros yields U–Pb age of 647 ± 5.3 Ma, which may represent the formation age of the ophiolitic mélange. The gabbros display low SiO2, TiO2, K2O contents, high Na2O, LREE contents and indistinctive REE fractionation [(La/Yb)N = 1.97–2.98]. It shows an E-MORB-like affinity, while the element concentrations of the Jifeng samples are lower than that of E-MORB. More importantly, Nb displays negative anomaly in comparison with Th, which shows a transitional SSZ-type ophiolite signature. Moreover, the εHf (t) values of ~647 Ma zircons in the gabbros range from +8.4 to +13.4, and the corresponding Hf single-stage ages (TDM1) are between 687 and 902 Ma, which is obviously older than the crystallization age of 647 Ma. These geochemical features can be explained as melts from the partial melting of a depleted mantle source meta-somatized by fluids derived from a subducted slab. Accordingly, we conclude that the Jifeng ophiolitic mélange is probably related to transitional SSZ-type ophiolite and developed in an intra-oceanic subduction, which indicates that an ocean (the Xinlin–Xiguitu Ocean) existed between the Erguna block and Xing’an block. The Ocean’s formation might be no later than the Neoproterozoic (647 Ma), and it was closed in the Late Cambrian because of the collision between the Erguna block and Xing’an block. © 2015, Springer-Verlag Berlin Heidelberg. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84958048479&doi=10.1007%2fs00531-015-1185-z&partnerID=40&md5=d50541ce90982c769d263993c3034a51
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/70192
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
There are no files associated with this item.
作者单位: College of Earth Sciences, Jilin University, Jianshe Str. 2199, Changchun, Jilin, China; State Key Laboratory of Continental Dynamics, Northwest University, Northern Taibai Str. 229, Xi’an, Shanxi, China; Key Laboratory of Mineral Resources Evaluation in Northeast Asia, Ministry of Land and Resources of China, Jianshe Str. 2199, Changchun, Jilin, China
Recommended Citation:
Feng Z.,Liu Y.,Liu B.,et al. Timing and nature of the Xinlin–Xiguitu Ocean: constraints from ophiolitic gabbros in the northern Great Xing’an Range, eastern Central Asian Orogenic Belt[J]. International Journal of Earth Sciences,2016-01-01,105(2)