山西袁家村组变沉积岩地球化学特征及构造意义

摘要 早元古宙袁家村组岩层是吕梁地区主要的含矿地层.对岩层样品进行元素地球化学组分测试，结果表明:主量元素以SiO2为主，次为Al2O3，TFeO和K2O，SiO2的含量与其他主要氧化物负相关;LILE和HFSE明显富集;稀土元素配分曲线具明显右倾的特征，轻重稀土分馏明显，轻稀土富集强烈;Ce异常极弱，Eu异常变化范围较大.袁家村组地层属副变质岩，原岩以沉积岩为主，沉积过程中风化作用较弱.物源性质以高成熟度的上地壳长英质沉积物为主，沉积过程可能混入了少量含古老沉积物成分和安山质岛弧火成岩组分的岩石，沉积构造环境为被动大陆边缘.
Abstract：Early proterozoic Yuanjiacun Formation is the main ore bearing stratum in Lyuliang district. The elemental geochemical compositions of the samples were tested. Results showed that the major element is mainly SiO2， then is Al2O3， TFeO and K2O in sequence. SiO2 exhibits negative correlation with the other major oxides， and LILE and HFSE are significantly rich. The rare earth element distribution curves take on obvious right-divergent characteristics， with strong fractionations of light and heavy rare earth and rich light rare earth. The Ce anomalies are extremely weak， and the range of Eu anomalies is relatively large. The Yuanjiacun Formation is parametamorphite， and the original rock is dominated by sedimentary rock with weak weathering during the deposition process. The provenance attributem is dominated by high-mature upper crustal felsic sediments mixed by small amount of rocks containing ancient sedimentary components and andesitic arc igneous rock components in the sedimentary process. The tectonic environment is passive continental margin.