The tin-mineralized north Dayishan granite body is a S-type granitic intrusion emplaced from southeast towards northwest along the Chenzhou-Shaoyang deep-seated fault zone.

• 大义山花岗岩体北体是矿田锡矿的主要成矿岩体,属燕山晚期“S”型酸性铝过饱和花岗岩,被动侵位于郴州-邵阳深断裂带走滑作用形成的剪切拉张桥区。