辽河三角洲LZK03孔全新世环境演变  

Holocene environmental changes revealed by Core LZK03 in the Liaohe River Delta. Geological Bulletin of China

作　　者：马宏伟[1] 车继英[1] 马诗敏[1] 崔健[1] 王长琪[1] 代雅建[1] 

机构地区：[1]中国地质调查局沈阳地质调查中心,辽宁沈阳110034

出　　处：《地质通报》2016年第10期1571-1577,共7页Geological Bulletin of China

基　　金：中国地质调查局项目(编号:1212011120171)

摘　　要：根据辽河三角洲LZK03孔岩心的地层、孢粉、^(14)C测年及粒度分析结果,重建了该孔全新世以来的沉积环境演变历史,划分了4个时期:1湖沼期,地层埋深22.70~18.35m,晚更新世晚期约8000cal BP,起始时间早于全新世底界年龄,一直持续到全新世海侵到达该地区;2海侵期,18.35~13.55m,8000~3000cal BP,全新世海侵(辽东湾命名为盘山海侵)于8000cal BP到达该地区,湖沼发育结束,随着海侵向陆扩展,形成了海相潮坪沉积;3海退期,13.55~7.50m,约3000cal BP开始海退,河流携带的泥砂成为主要物源;4盐沼期,7.50~0m,500cal BP时海水已退至LZK03孔向海一侧,经常暴露于地表的氧化环境使盐沼沉积呈黄棕色,被高潮海水淹浸的时间减少。In order to understand the coastal geoenvironmental changes in Holocene, the authors took a rotary-drilling core LZK03 in the Liao River Delta to conduct research work. Based on multidisciplinary approaches including stratigraphic logging, pollen analy-sis, ,4C dating and grain size analysis, the authors studied the Holocene sedimentary evolution of the core sediments. As a result, four geological periods were recognized as follows： ①Lacustrine stage, buried at the depth of 22.70？18.35m, which started its activity earli-er than the age of Holocene lower boundary and continued until Holocene transgression in the area;②Transgression stage, buried at the depth of 18.35？13.55m, locally named Panshan Transgression, which arrived in the area around 8ka cal BP and caused the end o f the previous stage and formed tidal flat deposits when the transgression further intruded inland.③Regression Stage, 13.55？ 7.50m, which started its activity around 3ka cal BP and then rivers produced major sediments in the area.④Salt marsh stage, buried 7.5？ 0m in depth and lasting from about 500cal BP to the present, during which the sea has retreated seaward from the core site. Consequent-ly, due to less marine inundation and frequent exposure, the oxidation environment colored the surface sediments yellow brown.

关 键 词：辽河三角洲 全新世 环境演变 

分 类 号：P534.632[天文地球—第四纪地质学]