锦州大笔架山连岛坝海域表层沉积物分布特征及物源分析

Distribution Characteristics and Provenance Analysis of Surface Sediments of Sea Near Mountain Big Bijia in Jinzhou

锦州大笔架山岛与大陆之间发育一条由砾石组成的天桥,是典型的连岛坝地质景观,本文采用综合法(筛析法+沉析法)对锦州大笔架山海域77个表层沉积物样品进行粒度分析,发现连岛坝周边表层沉积物类型主要为砾石、粉砂-砂-砾石、砾石质砂,向两侧粒径逐渐变细,并用Flemming三角图示法指示其沉积环境,结合相关性分析,分析海洋水动力条件。通过对表层沉积物中重矿物取样分析,确定连岛坝轻矿物组合主要为长石-石英,重矿物组合为绿帘石-普通角闪石-褐铁矿,与周边河流入海沉积物中矿物组合对比,结合周边海域地形地貌特征和水动力环境确定大、小凌河输入物质、海底再悬浮物质以及大笔架山基岩风化侵蚀产物是连岛坝海域表层沉积物的主要物质来源。

There is a bridge composed of gravel between Jinzhou mount Big Bija island and mainland,and it is a typical island dam geological landscape,By analyzing the 77 surface sediment samples of mount Big Bija sea area in the method of comprehensive（sieve analysis and laser particle size analyzer）,we found the bridge peripheral surface sediment types mainly for gravel,silt sand-gravel,pebbly sand,particle diameter tapering to each side.Through the analysis of heavy minerals in the surface sediment sampling,we determine the overpass light mineral assemblage mainly feldspar and quartz,heavy mineral combination of epidote-ordinary Angle of amphibole-limonite,Compared with the sea sediments mineral assemblage in the surrounding rivers,we determine the small Ling River sediment and mount Big Bija bedrock weathering erosion products are the main material source of bridge.