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Geochronology, geochemistry and Hf isotope of Late Triassic magmatic rocks of Qingchengzi district in Liaodong peninsula, Northeast China
被引:95
|作者:
Duan, Xiaoxia
[1
,2
]
Zeng, Qingdong
[1
]
Yang, Jinhui
[3
]
Liu, Jianming
[1
]
Wang, Yongbin
[1
,2
]
Zhou, Lingli
[1
,2
]
机构:
[1] Chinese Acad Sci, Inst Geol & Geophys, Key Lab Mineral Resources, Beijing 100029, Peoples R China
[2] Univ Chinese Acad Sci, Beijing 100049, Peoples R China
[3] Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China
基金:
中国国家自然科学基金;
关键词:
LA-ICPMS U-Pb dating;
Geochemistry;
Late Triassic magmatism;
Qingchengzi district;
North China Craton;
LITHOSPHERIC MANTLE BENEATH;
PLASMA-MASS SPECTROMETRY;
SULU OROGENIC BELT;
SINO-KOREAN CRATON;
PB ZIRCON AGES;
U-PB;
SOUTH-KOREA;
EAST CHINA;
LU-HF;
MOLYBDENUM DEPOSITS;
D O I:
10.1016/j.jseaes.2014.05.009
中图分类号:
P [天文学、地球科学];
学科分类号:
07 ;
摘要:
The initiation timing and mechanism of lithospheric thinning of the North China Craton (NCC) was still controversial. Late Triassic igneous rocks especially mantle derived mafic rocks would provide constrains on Early Mesozoic lithospheric mantle geodynamics and initiation of lithospheric thinning. This paper reports Late Triassic magmatic rocks, including lamprophyre, diorite dykes and biotite monzogranite cropped out in Qingchengzi district of Liaodong peninsula, northeastern NCC. LA-ICPMS zircon U-Pb dating yield ages of 210-227 Ma and 224 Ma for lamprophyres and biotite monzogranite respectively. Lamprophyre is ultrapotassic, strongly enriched in REE and LILEs, depleted in HFSEs, and negative Hf isotopes, which are discriminating signatures of crustal source, but distinguishingly high compatible element contents indicate the primary magma originated from mantle source a fertile one. Lamprophyre derived from partial melting of an enriched lithospheric mantle, which was modified by slab-derived hydrous fluids/melts associated with deep subduction between the Yangtze Craton and the NCC. The diorite displays distinct features with relatively enriched Nb, Ta, HREE and depleted Th, U, which suggest it derived from a relatively depleted source. The depletion was caused by break-off of the Yangtze slab during deep subduction introducing asthenospheric mantle into the source. The biotite monzogranite shows adakitic affinity, and originated from partial melting of the thickened lower crust with addition of small proportion of mantle material. The recognition of Late Triassic magmatism implies extensional tectonic settings in Liaodong peninsula and suggests initiation of lithospheric thinning of North China Craton in eastern segment might begin early in Late Triassic. (C) 2014 Elsevier Ltd. All rights reserved.
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页码:107 / 124
页数:18
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