%0 Journal Article
%T The structure profile of 0 - 1200m in the main borehole, Chinese Continental Scientific Drilling and its preliminary deformation analysis<br>中国大陆科学钻探主孔1200米构造柱及变形构造初步解析
%A XU ZhiQin
%A ZHANG ZeMing
%A LIU FuLai
%A YANG JingSui
%A TANG ZeMin
%A CHENG ShiZhong
%A CAI YaoChu
%A LI TianFu
%A CHENG FangYuan Laboratory of Continental Dynamics
%A <br>许志琴
%A 张泽明
%A 刘福来
%A 杨经绥
%A 唐哲民
%A 陈世忠
%A 柴耀楚
%A 李天福
%A 陈方远
%J 岩石学报
%D 2004
%I 
%X 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 - 1200 m) 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 m 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 m 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 (1) 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.
%K Chinese Continental Scientific Drilling
%K Sstructure profile
%K Ductile shear zone
%K Deformation analyses<br>中国大陆科学钻探
%K 构造剖面
%K 韧性剪切带
%K 变形解析
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=621CF755B1A341E5&jid=2013B5467E3054B1614CEC199353FCED&aid=CCFBF6F37CD18B13&yid=D0E58B75BFD8E51C&vid=A04140E723CB732E&iid=CA4FD0336C81A37A&sid=8E6AB9C3EBAAE921&eid=AA76E167F386B6B3&journal_id=1000-0569&journal_name=岩石学报&referenced_num=50&reference_num=30