The Kelameili ophiolite zone is located on the northern margin of the Tianshan orogenic belt, representing a suture between the Siberian and the Tarim continental blocks. The Nanmingshui area is a typical tectonic segment with continuous geologic outcrops and distinct petrological features. Based on the 1 : 50,000 mapping in the Nanmingshui area, the Kelameili zone can be divided into three petrotectonic units: the northern sub-zone consisting of Middle Devonian sedimentary rocks, the southern sub-zone consisting of Middle Devonian-Early Carboniferous sedimentary rocks and volcanoclastic rocks, and the ophiolitic melange sub-zone. These three sub-zones are divided each other by a fault. Red siliceous rocks, which overlie the basaltic layers of the Nanmingshui ophiolitic melange zone, contain rich radiolarians. The radiolarians are identified as of the Late Devonian Famenian in age, representing the age of the late stage forming the Kelameili ophiolite. From that, the closure time of the Tianshan Ocean should be no earlier than the Late Devonian.