The structure profile of 0 similar to 1200m in the main borehole,;Chinese Continental Scientific Drilling and its preliminary deformation;analysis

	The structure profile of 0 similar to 1200m in the main borehole,;Chinese Continental Scientific Drilling and its preliminary deformation;analysis
	Xu, ZQ; Zhang, ZM; Liu, FL; Yang, JS; Tang, ZM; Cheng, SZ; Cai, YC; Li, TF; Cheng, FY
刊名	ACTA PETROLOGICA SINICA
	2004
卷号	20 期号:1;SI SI 页码:53-72
关键词	Chinese Continental Scientific Drilling structure profile ductile shear zone deformation analyses
ISSN号	1000-0569
英文摘要	Based on the reconstruction of the spatial location of the drilling cores by using logging image data, we established a fine structural profile of the main hole (0 similar to 1200 in) of the Chinese Continental Scientific Drilling Project. Two lithological-tectonic units were recognized, the first one is composed of eclogite and ultramafic rocks, and the second one consists of paragneiss intercalated with eclogitic and ultramafic lenses. The foliations of the rocks from top to bottom change from steeply eastward dipping to gently southeastward dipping. Eclogite and ultramafic rocks in the first unit belong to the component of the Maobei eclogite complex. SN trending stretching lineations and shear fabric indicative of shearing deformation from north to south found in the eclogites represent the early stage deformation of the ultrahigh-pressure (UHP) metamorphic rocks. A 300 in thick ductile shear zone, possibly a downward extension of the Maobei ductile shear zone in the drilling hole, is found in the lower part of the profile between 738 and 1130 in within the second unit. Accompanying with from amphibolite to greenschist facies retrograde metamorphism, the shear deformation changed from early thrusting from SE to NW to later normal motion from NW to SE, as suggested by the shear strain and preferential orientation of quartz. In the context of regional geology around the borehole, we propose a new tectonic model in which ( I) the upper part is inverted syncline fold systems composed of the Maobei eclogite complex and paragneiss country rocks with SE plunge axial planes, and ( 2) the lower part is a ductile shear zone. The elasticity wave and thermal conductivity profiles of the core provide important petrophysical constraints to the interpretation of the seismic reflection and geothermal data. The VSP seismic profile reveals the deeply structure of the tectonic slices. The main hole verified that the strong reflective layer between 850 to 1130 m deep is equivalent to the ductile shear zone. Combined with results from field investigation of the exhumed Sulu UHP metamorphic terrain, these new data suggest an oblique extrusion of the UHP metamorphic terrain occurred concurrently with, but the dome formation postdated the exhumation.
学科主题	构造地质学
WOS关键词	MINERAL INCLUSIONS ; EASTERN CHINA ; DRILLHOLE ; DONGHAI
WOS研究方向	Geology
语种	中文
出版者	SCIENCE CHINA PRESS
WOS记录号	WOS:000221036600005
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/37779]
专题	中国地质科学院地质研究所
作者单位	Chinese Acad Geol Sci, Inst Geol, Lab Continental Dynam, Beijing 100037, Peoples R China.
推荐引用方式 GB/T 7714	Xu, ZQ,Zhang, ZM,Liu, FL,et al. The structure profile of 0 similar to 1200m in the main borehole,;Chinese Continental Scientific Drilling and its preliminary deformation;analysis[J]. ACTA PETROLOGICA SINICA,2004,20(1;SI SI):53-72.
APA	Xu, ZQ.,Zhang, ZM.,Liu, FL.,Yang, JS.,Tang, ZM.,...&Cheng, FY.(2004).The structure profile of 0 similar to 1200m in the main borehole,;Chinese Continental Scientific Drilling and its preliminary deformation;analysis.ACTA PETROLOGICA SINICA,20(1;SI SI),53-72.
MLA	Xu, ZQ,et al."The structure profile of 0 similar to 1200m in the main borehole,;Chinese Continental Scientific Drilling and its preliminary deformation;analysis".ACTA PETROLOGICA SINICA 20.1;SI SI(2004):53-72.