中文摘要：

牛首山-罗山断裂带是青藏高原东北缘最外侧的-条断裂带，其空间分布、深部结构、运动学特征以及变形机制对研究青藏高原东北角弧形断裂系的形成与演化具有重要意义。文中通过对横穿牛首山-罗山的4条地震反射剖面的解释及断裂带部分地区大比例尺的构造地质填图，发现牛首山-罗山断裂带具有不连续性与分段性。断裂带南段罗山断裂以正花状构造为特征，显示断裂具有右旋走滑性质；中段牛首山东麓断裂可能并不存在，该区以强烈的褶皱变形为特征；北段三关口断裂则以左旋走滑为特征。牛首山-罗山断裂带的这种不连续性和分段性反映了断裂带的不同构造部位在青藏高原向NE方向扩展过程中具有不同的变形样式。

英文摘要：

As the outermost fault zone in the northeastern margin of the Tibetan plateau, the deep structures,distribution, movement feature and deformational mechanism of the Niushoushan-Luoshan Fault zone are crucial to understand the formation and evolution of the arcuate fault zones in the northeast corner of the Tibetan plateau. In this paper, we analyze four seismic reflection sections across the Niushoushan-Luoshan Fault zone and map in detail the area within the fault zone. These data indicate that the Niushoushan-Luoshan Fault zone is a discrete fault zone. The fault zone can be subdivided into three parts： the south part,i, e. the Luoshan Fault,is characterized by positive flower structure, shown as remarkable right lateral strike-slip; in the middle segment, that is, the Niushoushan Fault, no active fault exists on the east flank of the Niushoushan, and this region is dominated by intensive folding; the north part,the Sanguankou Fault,is a left-lateral strike-slip fault. The discontinuity and segmentation feature of the Niushoushan-Luoshan Fault zone suggest different deformational styles in different locations of the fault zone associated with the process of northeastward propagation of the Tibetan plateau.