吕梁山区早元古代地层层序探讨

Disscussions on Stratigraphic Sequence of Paleoproterozoic Era in Luliang Mountains Area

笔者根据吕梁山区中段１∶５万盖家庄幅、马坊幅区调，发现前人所建立的下元古界野鸡山群以变质基性火山岩为核的向斜两翼岩性差异较大，岚河群在宝塔山一带呈倒转向斜产出，且发育两层基性火山岩。通过全区地层剖面分析、对比，认为下元古界黑茶山群、野鸡山群和岚河群并非依次上下叠置关系，而是侧向相变关系，并初步建立了早元古代岩石地层格架。

During mapping 1∶50000 Gaijiazhuang sheet and 1∶50000 Mafang sheet in the Luliang Mountains area,the authors discovered some important differences between two limbs of a syncline which was constituted by Paleoproterozoic Yejishan group with its core of metamorphosed basic volcanic rocks,and a Lanhe Group occurs as an overturned syncline in which two layers of metamorphosed basic volcanic rocks are developed.Basing on the analysis and correlation of the stratigraphic sections in the Luliang Mountains area,the authors consider that the relations among the Heichashan Group,Yejishan Group and Lanhe Group are not normally the upper and lower superimpositions,but those of the lateral facies changes,and thus tentatively put forward a new lithostratigraphic frame of Paleoproterozoic in the region.It may be of significance for the basin analysis of Paleoproterozoic taphrogenic trench.