【摘要】 渤海湾地区广泛分布的古海面标志物,为建立该地区的相对海面变化曲线提供了良好的基础。过去 20年来该地区已相继建立了一些相对海面变化曲线,但在讨论影响古海面标志物高程的因素时,未将构造活动与水动型海面变化及均衡作用对高程的贡献量加以区分。文章以该地区 7个点的古海面标志物及相关层位的高程测量与年代学测定结果,经与地区性预测海面变化曲线进行对比后,定量讨论了该地区海面变化(包括绝对海面变化与冰川、水均衡作用)与构造活动对古海面标志物高程的贡献;并以壳体的稳定同位素、地层记录与古地震研究资料讨论了牡蛎礁体在建礁过程中所记录的构造下沉。更多还原

【Abstract】 The widely scattered paleo-mean sea-level indicators along the Bohai Bay supply basic foundation for reconstructing of relative sea-level change in this area. During the past 20 years, scientists had built some relative sea-level curves in this area. However, they mixed all the impacting factors to the elevation of paleo-mean sea-level indicators up when they built this curves. A spatial-temporary distribution of such seven indicators, corresponding with the regional predicted sea-level curve, is established to calculate the subsidence of each indicator. Therefore, we can distinguish the contributions of tectonics and sea-level change associated with glacio- and hydro-isostatic adjustment in the local area to the elevations of the indicators. Furthermore, with the results of stable isotopic analyses to the oyster shells in the Biaokou reef and a paleo-earthquake trace in Dawuzhuang reef, we discuss the tectonic subsidence during the buildup of the reef bodies. And we compare the result to a strong paleo-earthquake event occurred in this area with spatial distribution map and 14C dating ages. As proxies, the results of oxygen and carbon isotopic analyses to the shells, lying on different vertical positions in one section, have indicated tectonic movements and subsidence recorded in the reef body while it was building up.更多还原