Deformation feature and significance of Early Paleozoic hornstone fossil in Gangtangcuo area, central Qiangtang, northern Tibet, China

The study region is located in the southern edge of the Eurasian continent and Gondwana land, where the Longmucuo-Shuanghu-Lancangjiang suture passes by through the northern part. By means of field geological mapping, we found there are abundant hornstone fossils in early Paleozoic strata. These fossils have distinct features indicating ductile deformation, such as boudinage structure and σ—type shear structure in cross-section. It′s shown by all these features that this study area has experienced strong structural displacement, strata within this area display as generally in disorder but locally in order and belong to typical non-Smith strata. This understanding is important for stratigraphic division in the study area.