渤海湾西沧县隆起第四纪以来沉积差异性研究

沧县隆起是渤海湾盆地的重要组成部分。通过对沧县隆起上施工的350m深ZKT1钻孔沉积特征、测年(AMS14C和OSL)及磁性地层研究,并与CGZ5、BZ2孔磁性地层及海侵层对比,结果发现:沉积岩层M/G(松山/高斯,Matuyama/Gauss)极性带界线埋深存在较大沉积差异,B/M(布容/松山,Brunhes/Matuyama)极性带界线趋于一致,3期海侵层基本稳定;早更新世沧县隆起不同部位存在沉积差异,继承了古近纪以来的断陷沉积;中更新世-晚更新世沧县隆起准平原化,整体处于同一稳定下沉的沉积演化环境;晚更新世以来,发生三期区域性层位较稳定的海陆交互作用,形成滨海冲积平原。本文可为渤海湾地区新构造活动性研究及区域古地理恢复与地质演化提供参考。

Study on sedimentary difference at the Cangxian Uplift in the west coast of Bohai Bay since the Quaternary Period

Cangxian uplift is a main part of the Bohai bay. Study oo the sedimentary characteristics, dating (AMS¹⁴C, OSL) and magnetic strata of the 350 m-deep drill hole ZKT1 on the Cangxian uplift and correlation of magnetic stratum and transgression layer of the drill hole CGZ5 and the BZ2 show that there was a large sedimentary difference in the depth of the M/G boundary (Matuyama/Gauss), the B/M boundary (Brunhes/Matuyama) tends to be uniform, and the three transgression layers are basically stable; sedimentation is different in different parts on the uplift in the early Pleistocene succeeding sedimentation in fault depression sinse paleogene; peneplaination of the uplift occurred in the period of Middle Pleistocene-Late Pleistocene when the whole uplift was under a stable sinking sedimentary evolution environment; Since the late Pleistocene, three episodes of more stable sea-land interactions occurred in the regional strata forming coastal alluvial plains. This work provides important reference materials for the study of neotectonic activity and regional paleogeographic restoration and geological evolution.