Abstract: The preliminary data are presented on microstructures of the gabbric mylonites from the Hongliuhe (HLH)(红柳河) ophiolitic complex, in the border area between Xinjiang and Gansu, NW China. The HLH ophiolitic complex are remnants of the Silurian South Tianshan oceanic crust, while the Mid-Tianshan Terrane collided with the Tarim plate in the Upper Carboniferous. The accumulative gabbros from the HLH ophiolites preserve a fine example of mylonitic rocks. The ductile deformation of clinopyroxene and plagioclase in HLH area are different from those in granulite terrain of North China craton. Generation of these gabbric mylonites is interpreted instead as due to ductile shear at the lower oceanic crust near the spreading centre, soon after new oceanic crust was formed.

Key words: Hongliuhe ophiolitic complex, accumulative gabbros, gabbric mylonites

摘要： 新甘交界处的红柳河蛇绿岩套中发育辉长质糜棱岩，辉石、斜长石具有良好的塑性变形特征。辉长质糜棱岩主要集中于蛇绿岩套的堆晶辉长岩单元内，可能是洋壳生成后不久下部不同层次间滑脱的产物。

关键词: 红柳河蛇绿岩, 堆晶辉长岩, 辉长质糜棱岩