大古峰(花岗岩锥形峰) Dagu Peak: Granite Conical Peak 顶平、上细、下粗的锥形花岗岩孤峰，高近100米，面积近2640平方米。为细粒碱性长石花岗岩受稀疏节理切割，经雨水、冰冻风化剥蚀、重力剥落而成。 The conical granite isolated peak, with flat top, thin upper part and thick lower part, isnearly 100m highwith an area of nearly 2,640 km. The peak is formed as the fne-grainalkaline feldspar granite is incisedby sparse joints and suffers from weathering and enudationof rains and frosts as well as gravitationalspalling.