| 摘要: |
| 对莱州浅滩80 个表层沉积样品进行碎屑矿物分析, 主要研究重矿物分布特征, 并探讨其物质来源。研究表明: 本区优势矿物组合为普通角闪石-绿帘石-黑云母-褐铁矿, 可划分成5 个矿物区。浅滩滩体(Ⅰ区和Ⅱ区)稳定矿物(以榍石、石榴子石为主)含量高。浅滩北部顶端(Ⅱ区)金属矿物类分布集中, 褐铁矿含量近1/3; 浅滩两侧(Ⅲ区和Ⅳ区)为云母类高值区。浅滩西侧海域(Ⅳ区)含大量自生黄铁矿, 为还原性沉积环境;浅滩西北(Ⅴ区)重矿物含量最高, 优势矿物组合为普通角闪石-绿帘石-石榴子石。依据重矿物种类和矿物组合特征, 结合陆源近岸河道及黄河沉积物矿物特征, 研究显示: 浅滩滩体沉积物主要为近岸河流输送, 而浅滩两侧沉积物是双重来源, 既来自陆地近岸又来自黄河物质向东的输送。矿物区的变化反映了该区水动力的复杂性。重矿物分布特征对研究本区海洋动力环境和探讨浅滩物源都有重要意义。 |
| 关键词: 重矿物 分布特征 物源 莱州浅滩 |
| DOI：10.11759/hykx20131021001 |
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| 基金项目:山东省自然科学基金(重点)(Z2008E03); 国家海洋局海洋沉积与环境地质重点实验室开放基金(MASEG200803) |
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| Characteristics of heavy mineral distribution and provenance in surface sediments of the Laizhou Shoal |
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| Abstract: |
| Eight samples obtained from surface sediment of the Laizhou Shoal were investigated by detrital minerals analysis, with focus on characterization of heavy mineral distribution and investigation of their provenance. The Studies show that in this sea area, the advantaged mineral assemblages mainly consist of hornblende-epidote-biotite-limonite and this area can also be divided into five heavy mineral districts. The main body of shoal (Ⅰ and Ⅱ District) is rich in stable minerals (mainly consist of the sphene and garnet -based). The tip of northern shoal (Ⅱ District) has a concentrated distribution of metallic minerals, and nearly one-third of the heavy minerals is limonite. The mica is in high content at both sides of shoal (Ⅲ and Ⅳ District). The west sea of shoal (Ⅳ District) as reducing depositional environment has a lot of authigenic pyrite; the northwest of the shoal (Ⅴ District) has high content of heavy minerals, and the advantaged mineral assemblages in this area is hornblende - epidote - garnet. On the basis of the kinds of heavy minerals and characteristics of the mineral assemblages, combined with terrestrial nearshore riverway and characteristics of the Huanghe River’s sediment minerals, the study shows that the sediments of the shoal body are mainly transported by inshore river, while the sediments’ source of both sides of the shoals is double, not only from inshore land but also from the eastward delivery of the Huanghe River. The changes of the mineral districts reflect the complexity of the hydrodynamic in this sea area. |
| Key words: heavy mineral characteristics of distribution material source the Laizhou Shoal |
