关键词: 滨海黄土, 粒度, 辽南

Abstract:

Research on grain size of seashore loess in Liaodong Peninsula indicates that kind of loess was the product of frigid climate in Quaternary ice age Due to geographical locations adjacent to coastal zone, the loess has distinctive formation process compared with loess in other areas Divulged alluvium and sands of Bohai seabed in the last glacial period constitute another important material source of this loess which are transported by sand saltation mode Grain size of this seashore loess bears a great deal of formation about changes of Bohai sea level Sedimentary process of this seashore loess is controlled by two factors, which are wind power and Bohai sea level's fluctuation in the last glacial period Wind deposits derived from adjacent source of materials make grain size distribution of this loess from normal to abnormal Goodness of fit of grain size distribution and 2 3Φ size percentage content reflect history of transgression and regression of Bohai Sea and strong and weak Mongolian high pressure of the last glaciation. These changes are identical with paleo environment reflected by sporo pollen assemblage, and also corresponding to sea leeventsl changes in the neighbouring areas and stage of δ 18 Ο/ 16 Ο Goodness of fit of seashore loess grain size distribution is a major substitutional index of paleo environmental changes Heinich events are recorded in Rosin's grain size distribution There are 5 high values of goodness of fit of Rosin's grain size distribution in profile of this seashore loess These events of high values occurred in transgression period of Bohai Sea during early and later phase of the last glacial period, and are records of extreme cool events which occurred during the last glacial period It is difficult to compare these events with Heinich events due to limitations of precision of chronological orders

Key words: seashore loess, grain size, south Liaoning province