摘要
CCSD主孔100～2 950 m榴辉岩、退变榴辉岩类岩石叶理倾角明显较片麻岩类岩石叶理倾角陡,前者总体倾角55°左右,后者28°左右,局部可见片麻岩类叶理切割榴辉岩类叶理,因此两者叶理可能形成于不同时期;两类岩石之间现部分为韧性剪切带接触关系,韧性剪切带形成于苏鲁地体折返主期自SEE向NWW的韧性剪切作用.榴辉岩、退变榴辉岩类岩石叶理产状对发育于该类岩石内的微断层产状有一定控制作用,而片麻岩类岩石叶理产状对发育于该类岩石内的微断层产状控制作用相对较弱.孔区脆性变形主要反映白垩纪以来SEE-NWW向伸展构造应力场的变形特征,主孔100～1 620 m倾伏向以SEE向占绝对优势的微正滑断层擦痕即为该期变形的产物.
The dip angles of eclogite and retrograde metamorphic eclogite type foliations in 100-2 950 m core of the CCSD main hole are obviously steeper than the angles of gneiss type foliations, with the former angles being generally 55° or so and the latter around 28°. Foliations of gneiss type locally dis.sect foliations of eclogite type, and hence foliations of these two types might have been formed in different periods. The contact relation between the two types of rocks is that of ductile shear zone formed during SEE-NWW ductile shearing at the main exhumation stage of Su-Lu terrane. Foliation attitude of eclogite and retrograde metamorphic eclogite plays a certain role in controlling attitude of miniature faults in eclogite type rocks, whereas foliation attitude of gneiss type exerts a relatively weak role in controlling attitude of miniature faults in gneiss type rocks. Brittle deformation in the main hole mainly reflects deformational characteristics of the SEE-NWW extensional tectonic stress field since Cretaceous. The striation plunging of miniature normal faults in 100-1 620 m core of the main hole is predominantly in SEE direction, and this evidently results from deformation of this stage.
出处
《岩石矿物学杂志》
CAS
CSCD
北大核心
2005年第5期438-442,共5页
Acta Petrologica et Mineralogica
基金
科技部973项目(2003CB716500)
中国地质调查局地质大调查项目(121201056606)
中国大陆科学钻探工程项目资助
关键词
CCSD主孔
榴辉岩
退变榴辉岩类
片麻岩类
叶理
微断层
the CCSD main hole
eclogite
retrograde metamorphic eclogite type
gneiss type
foliation
miniature fault
