湄洲湾重矿物组合及分布特征

Assemblages and distribution characteristics of heavy minerals in Meizhou Bay

湄洲湾重矿物平均含量5.67%,高于台湾海峡中北部的(0.96%),>10%的高值区分布于湾内深槽的岛屿附近,<3%的低值区见于近岸海域。重矿物37种,以磁铁矿、角闪石、绿帘石、褐铁矿等为主。根据重矿物的含量可将其分为6个矿物区。湾内物质来源于河沙、岸边、岛屿和海底蚀沙及台湾海峡来沙。湾内与海峡之间进行物质交换,磁铁矿、锆石等颗粒状矿物由湾内向海峡方向扩散,而黑云母等片状矿物则由海峡向湾内扩散。湄洲湾处于较氧化的高能环境。

The average content of heavy minerals in the Meizhou Bay,Fujian is 5. 67%,higher than the average in the Taiwan Strait (0. 96%). The heavy minerals content larger than 10% which is considered as higher-value region,is located in the region close to the islands of deep trough of among the Bay. The lower-value region,less than 3% of heavy minerals is located in the offshore area.37 Kinds of heavy minerals, magnetite, amphibole, epidote, limonite and so account for 81% and have their presence in all stations. Material source in the Meizhou Bay is various. It comes from the river runoff,the denudation of coastal rock, the sea erosion of islands and sea-fioor and offshore contribution.There are exchange of materials between the Meizhou Bay and Taiwan Strait. The granular minerals, such as magnetite,zircon, diffuse from the Bay to the Strait. The schistose minerals, such as biotite, diffuse from the Strait to the Bay.The study shows the Meizhou Bay is an oxidized environment under high-energy effects.