鲁西南汶上凹陷官庄群沉积特征及演化分析

Sedimentary characteristics and evolution analysis of Guanzhuang group in Wenshang sag,southwestern Shandong

汶上凹陷位于鲁西隆起区,地表第四系覆盖,区域上古近纪官庄群为含盐岩系,该区研究程度较低。通过收集以往钻孔资料,对汶上凹陷古近纪官庄群进行系统划分对比,将区内官庄群自下至上划分为常路组、朱家沟组、大汶口组,常路组为河流相沉积,朱家沟组为山麓洪积相沉积,大汶口组为湖相沉积。大汶口组岩石组合具明显三分性(上段、中段、下段),其中中段为含膏层。建立了区内官庄群地层格架,探讨了其形成演化以及成矿条件。

Wenshang sag is located in Shandong west uplift zone,surface quaternary cover.The Guanzhuang group in paleogene period is a saline rock system,and the research level of this area is low.By collecting the borehole data of past,Guanzhuang group in paleogene period in Wenshang sag of systematic classification and correlation could be divided into Guanzhuang group from the bottom-up Changlu formation,Zhujiagou formation and Dawenkou formation.Changlu formation is sedimentary fluvial facies,Zhujiagou formation is sedimentary piedmont pluvial facies,Dawenkou formation is lacustrine deposition.The rock assemblages of Dawenkou formation have obvious separability(upper、middle and lower segments),wherein the middle segments is containing the gypsum layer.The stratigraphic framework in the area was established,and the formation,evolution and metallogenic conditions were discussed.