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坪道岩体由早期到晚期可分出斜长花岗岩→花岗闪长岩→黑云二长花岗岩→含斑黑云二长花岗岩→正长花岗岩共5期岩浆活动。岩体碎裂化强,构造蚀变带发育。碱值(NK/A)为0 49～0 62,ANKC值大于1,见白云母,CIPW计算中多见刚玉,为钙碱性铝过饱和型。随SiO2含量增加,TiO2、FeO、MgO、CaO、Na2O均逐渐缓慢减少,而Fe2O3和K2O含量在剧增。岩石化学显示其源岩为上地壳杂砂岩类、碎屑岩类。岩体相对富集轻稀土,δEu值为0 35～0 7,铕亏损强烈。岩体贫Ba、Rb、Sr、Y、Cu、Zr、Ga、Ni元素,富Nb、Ta、Bi、Th、Cr、Sn、Mo、Hf、Au、Sc,异常富Hf、Sn、Sc、Au,数个构造破碎带及蚀变带有金矿化显示(0 2～0 4g/t),综合分析该岩体较有利于金矿的形成。
From the early stage to the late stage, Pingdao pluton can be divided into five stages of magmatism: plagiogranite → granodiorite → biotite granite → plagioclase → monzogranite → granite. Rock fragmentation strong, structural alteration zone development. The base number (NK / A) is 0 49 ~ 0 62, ANKC value is greater than 1, see muscovite, CIPW calculation more common corundum, calcium-alkaline aluminum supersaturated type. With the increase of SiO2 content, the content of TiO2, FeO, MgO, CaO and Na2O gradually decreased, while the content of Fe2O3 and K2O increased sharply. Petrochemistry shows that the source rocks are upper crustal sandstones and clastic rocks. The relative enrichment of light rare earth rock, δEu value of 0 35 ~ 0 7, europium loss is strong. The rock mass is poor in elements such as Ba, Rb, Sr, Y, Cu, Zr, Ga and Ni, Nb, Ta, Bi, Th, Cr, Sn, Mo, Hf, Au, Sc, Hf, Sn, Sc, Au , A number of structural crustal zones and alteration zones with gold mineralization (0 2 ~ 0 4g / t). Comprehensive analysis of the rock mass is more favorable for the formation of gold deposits.