山东半岛莱州湾滨海地区黑土湖组地层特征、时代及指示的全新世海岸带变化  

Stratigraphic Characteristics, Age and Indicated Holocene Coastal Variation of Heituhu Formation in Laizhou Bay Coastal Area, Shandong Peninsula

作　　者：徐建国[1] 徐华[1] 张涛[1] 张卓[1] 祁晓凡[1] 纪汶龙[1] XU Jian-guo;XU Hua;ZHANG Tao;ZHANG Zhuo;QI Xiao-fan;JI Wen-long(Shandong Institute of Geological Survey,Jinan,Shandong 250013)

机构地区：[1]山东省地质调查院,山东济南250013

出　　处：《地球学报》2018年第2期133-143,共11页Acta Geoscientica Sinica

基　　金：中国地质调查局地质调查项目(编号:1212011220001;J50E018023;J50E019022;J50E019020;J50E017021;12120114033801)资助~~

摘　　要：地质调查发现,山东半岛西北部的莱州湾滨海地区普遍发育黑土湖组滨海湖沼相、潟湖相沉积,其下伏末次盛冰期泛滥平原相沉积,上覆全新世中晚期海侵层。黑土湖组的分布受古地形和全新世海侵的影响,其形成时代为8.5—5.5 ka B.P.,即由现代海岸线附近因8.5 ka B.P.前后海面上升环境效应开始出现,向陆地方向逐渐过渡到最大海侵线附近的5.5—6.0 ka B.P.期间形成。该地层单元的穿时性指示了海侵向陆地方向的推进,以及大约自5 ka B.P.开始河流沉积作用超过海面高度,莱州湾开始逐步成陆的过程。研究表明,莱州湾地区东部的鲁东地块相对抬升,造成黑土湖组顶板高出现代海面。西部的济阳坳陷区沉降较大,造成黑土湖组埋深较大。莱州湾南岸黑土湖组单元形成的古地形坡度,与现代地形坡度接近,在5.5—8.5 ka B.P.期间的海面变化不大。新的研究结果为更深入认识山东半岛全新世海岸带变化提供了重要依据。Deposits of coastal limnetic facies and lagoonal facies of Heituhu Formation are commonly distributed in Laizhou Bay coastal area in the northwest of the Shandong Peninsula,and are sandwiched between an underlying flood plain deposit of the last glacial maximum and overlying middle and late Holocene transgressive strata.The distribution of Heituhu Formation was affected by ancient landform and Holocene transgression,and the age of the formation is 8.5–5.5 ka B.P..It appeared as a result of environment effect of sea level rise from the vicinity of modern coastline 8.5 ka ago,was spread toward land,and ended at the farthest transgression line about 5.5–6.0 ka B.P.ago.The diachronism of strata indicates the transgression advanced towards the land,and the process of river deposition surpassed sea surface elevation and formed the Laizhou Bay about 5 ka B.P.ago.Studies show that the relative uplift of Ludong land mass made the roof of the Heituhu Formation higher than the modern sea level.Western Jiyang depression had greater settlement,which caused greater buried depth of Heituhu Formation along the west seashore of the Laizhou Bay.The ancient topographic slope during the generation of the formation along the south seashore of Laizhou Bay was similar to the slope nowadays,which indicates that the sea level had little change during 5.5 ka B.P.to 8.5 ka B.P..The new research results can provide important evidence for a better understanding of the Holocene coastal variation of Shandong Peninsula.

关 键 词：山东半岛 黑土湖组 全新世海侵 海岸线迁移 海平面变化 

分 类 号：P534.632[天文地球—第四纪地质学] P737.15[天文地球—古生物学与地层学]