廉州湾重矿物组合区与泥沙来源

Heavy Mineral Assemblys and Silt Sources in the Sediment of Lianzhou Bay

关键词:  海湾  重矿物  泥沙来源  泥沙运移

Key words:  bay  heavy mineral  silt source  silt transport

摘要:

对廉州湾50多个沉积物样品0.125~0.063mm粒级的重矿物(比重大于2.89的碎屑矿物)分析,发现3个重矿物组合区:(1)南流江口矿物区即电气石-锆石-钛铁矿-浅渌角闪石组合区;(2)西南部大风江口矿物区即钛铁矿-电气石-锆石组合区;(3)东南部北海港矿物区即电气石-钛铁矿-锆石-黑云母组合区。陆相径流(南流江流域)来沙是廉州湾的主要物源,也有部分物源是来自南部海岸的侵蚀物质,海相来沙是很少的。海湾泥沙运移总趋势是自东北向西南运移,但南部沿岸泥沙自西南向东北运移。

Abstract:

According to the outcome of analysis of 50 samples of the heavy minerals at 0.125~0.063 mm in size with specific gravity more than 2.89 in the sediment of Lianzhou Bay, three areas of heavy mineral assemblys are found:(1) tourmalin-zircon-ilmenite-greenish hornblende assembly in the mouth of Nanliu river,(2) Ilmenite-tourmalin-zircon assembly in the mouth of Dafeng river,southwestern Bay,(3) tourmalin-ilmanite-zircon-biotite assembly in Beihai Harbor,southeastern Bay.The sediments carried by continental runoff(Nanliu river) are the main material sources for Lianzhou Bay Some of materials come from the erosion of the southern coast. Silt from marine faces are quite few. The general trend of silt transport in Lianzhou Bay is from northeast to southwest, but southwest to northeast in the southern coast.