引用本文：商志文,李建芬,姜兴钰,李琰,王宏.2020.大凌河河口地区中更新世晚期以来沉积环境演化[J].地质学报,94(8):2433-2445. SHANG Zhiwen,LI Jianfen,JIANG Xingyu,LI Yan,WANG Hong.2020.Sedimentary environmental evolution of the Dalinghe Estuary area since the Late Middle Pleistocene[J].Acta Geologica Sinica,94(8):2433-2445.
Abstract:The comprehensive studies of sedimentology, micropaleontology and chronology of borehole LZK06 at 40m depth and combined with the data of boreholes LZK02- 04 in the Dalinghe estuary area revealed that the study area experienced two transgression- regressions since the Late Middle Pleistocene, and the Late Middle Pleistocene lacustrine/fluvial Late Pleistocene marine lacustrine/fluvial Holocene marine fluvial stratums were sequentially formed. In the Early and Middle Holocene, due to the lower source supply, the study area was in a 10 ka long phase of starving deposition environment with an average sedimentary rate of 0. 02~0. 05 cm/a. In the Late Holocene, about 1500 years ago, due to the human activities leading to soil erosion and increased sediment transport in the river, the study area began a rapid accretion process with an average sedimentary rate of 0. 9~1. 2 cm/a, and the lower Liaohe plain was quickly filled. Compared with the tempo- spatial pattern of global sea level change, it is speculated that the marine bed II was formed in MIS 5- early MIS 3 and marine bed I was formed in MIS 1. Frequent sea level change is the main controlling factor for stratigraphic and environmental evolution in the muddy coast of Liaodong Bay since the Late Pleistocene.