The Cóc §­êng area is a graben formed by a process of extension and subsidence with a great depth. The deposition of clayey formation and dome - forming compression created good conditions for the formation of endogenous ore. There still are acidic effusives in this area. Manifestations of lead - zinc mineralization in stream beds of great erosion have been showing that the exposed part on the surface is only the uppermost part of the ore body, as for the important part of ore bodies it still lies in the depth. The Cóc §­êng ore zone occurs not only in the Cóc §­êng area, but also farther in its northeast.