论北京平谷新生代盆地的成因*

通过对北京市东北部平谷新生代盆地地层岩性、水文条件、深部构造、微小地震和盆地形态特征综合分析,提出平谷盆地并非第四纪断陷盆地,而是岩溶塌陷盆地的新认识。综合研究认为平谷盆地内基岩断裂可能大量发育;但新生代夏垫-马坊断裂带并没有在平谷盆地内发育;造成平谷盆地新生代断裂密布假象的原因是基岩埋藏古地貌;平谷盆地古溶洞形成时代可能为上新世-早更新世,盆地可能在早更新世发生塌陷,形成最初的盆地雏形。

The cause of Beijing Pinggu basin in Cenozoic era*

This article analysises that Pinggu Basin is not the type of Quaternary period graben basins but belongs to the type of karst collapse basins, through the comprehensive analysis of _Sstratum lithology, hydrologic condition, fault, low-levelSearthquakeSand flat form of the cave. We propose that the faults may exist in bedrock areas in the Pinggu Basin, Xiadian-Mafang Fault zone is inactive or is not existing. The reason of false impression, Mesozoic and Cenozoic faults is existing, is buried palaeogeomorphology. In addition, the fact that the formation time of the karst caves at Pinggu Basin should be from the early Pliocene to Pleistocene was also be discussed.