In the present study, we have used methods of petrography and mineral chemistry to study alteration and low-grade metamorphism of Ordovician volcanic rocks in Mayahsuehshan, Minleh and Changma areas.

• 本研究针对甘肃省马雅雪山、民乐以及昌马地区之火山岩，从岩象和矿物化学的角度来探讨火山岩所受的蚀变作用或变质作用。