广西龙头山金矿床岩浆活动的新认识

Research on Magmatism Activities of Longtoushan Gold Deposit in Guangxi

龙头山金矿床产在平天山岩体西侧的一个残留的燕山晚期火山颈中,矿区出露有花岗斑岩、流纹斑岩、花岗斑岩脉和霏细斑岩脉等.通过野外实地调查和资料分析,认为流纹斑岩形成时间晚于花岗斑岩;龙头山岩浆活动可分两个旋回:第一个旋回为浅成侵入相的花岗斑岩;第二个旋回包括次火山岩相的流纹斑岩和晚期的酸性、中酸性岩脉两个亚旋回;龙头山金矿床成矿作用主要与流纹斑岩有关.

The Longtoushan Gold Deposit, located at the west of Pingtainshan rock body, occurs in a residual volcanic neck of late Yanshanian period. Granite porphyry, rhylite porphyry, granite porphyry vein and felsite porphyry vein were found in the ore field. Analysing the previous work and measuring section prove that the porphyry forms later than Granite porphyry. The magmatism activities of Longtoushan gold deposit can be divided into 2 cycles including hypabyssal intrusive phase and subvolcanic rock factes. The hypabyssal intrusive phase is consisted of granite porphyry; the subvolcanic rock factes is consisted of rhylite porphyry and late period granite porphyry vein and felsite porphyry vein. Rhylite porphyry is the most important factor for the mineralization of Longtoushan Gold Deposit.