辽南大莲泡沉积物的沉积特征及古环境变化

Sedimentary characteristics of the Dalianpao Sediment in Southern Liaoning and Its Paleoenvironment Changes

辽南大莲泡是形成于冰后期的一个现已干涸的小型山间湖泊。对大莲泡沉积物粒度作一般分析，并用对应因子分析法作了计算分析，结果表明：大莲泡沉积物粒度分布主要受入湖的沟谷泥石流、河流和湖泊沉积作用控制。即下层以泥石流沉积为主；中层以湖泊沉积为主；上层以河流作用为主。据此并结合孢粉分析资料（主要以湿生沼生和旱生、盐生草本孢粉带更替为依据），初步恢复了大莲泡沉积环境的演变过程。全新世高海面在辽南地区是存在的，大莲泡与海相通的特殊位置及地层特征和孢粉特点揭示在全新世气候最适宜期海水在涨潮时曾作过短暂的停留，高海面在渤海沿岸出现位置不超过现代海面之上５ｍ。

Dalianpu, located in the south of Liaodong Peninsula, is a small dried intermountane lake formed during Holocene. There is a thin bed of sediments in the lake basin. The sediments takes bimodal, multimodal and unimodal forms in size histogram. The parameters vary in the section. On the basis of the data of the grain size anellysys, the author adopts the method of correspondence factor analysis and comes to conclusion that F 1-factor representsa high-energy environment. The grain size distribution of the sediments is controlled by debrisflow process, mountain torrents and lake deposit process, which results from changes of depositional paleoenvironment of the Dalianpu lake.