摘要
通过对山东半岛近海274个表层沉积物的粒度和常量元素的系统研究,探讨了该海域常量元素地球化学特征、空间分布规律及其影响因素。研究表明,山东半岛近海海域表层沉积物的常量元素较为稳定,主要由SiO2、Al2O3、Fe2O3、MgO、CaO、Na2O和K2O组成,其中SiO2和Al2O3含量最高,分别为65.3%和12.5%;常量元素含量与沉积物类型密切相关,SiO2含量随沉积物类型变粗而逐步降低;Al2O3、Fe2O3、MgO、MnO、P2O5和K2O含量随沉积物类型变细逐步增大;TiO2和Na2O含量基本不受沉积物粒度的影响;受黄河沉积物的影响,CaO含量在黏土类型沉积物中迅速升高。常量元素相关性和R型正交旋转因子分析表明,研究区内常量元素可划分为3类,第1类包含SiO2、Al2O3、Fe2O3、MgO、K2O、TiO2、P2O5、TOC,代表了陆源碎屑沉积;第2类主要由CaO、CaCO3组成,代表了海洋生物作用;第3类由Na2O、MnO组成,代表了海洋化学沉积作用。研究区内大部分表层沉积物的化学风化指数(CIA)为50～65,沉积物的物源变化可能对CIA起主要的控制作用。CIA和TiO2/Al2O3比值共同指示黄河源沉积物主要分布在山东半岛沿岸海域,与陆源因子F1的得分系数基本一致,其分布模式与研究区海洋环流和地形特征密切相关。
In this study, a total of 274 surface sediments from the offshore area of Shandong Peninsula were collected and analyzed for grain-size, total organic carbon （TOC）, and major elementss. Results show that SiO2is the highest major element, followed by Al2 O3 as the second. These two major elements make up 77.8% of the total major elements. The composition of major elements depends upon the type of sediment or grain-size. SiO2 is usually enriched in the coarse-grained sediments, whereas Al2O3 ,Fe203 ,MgO.MnO. P2O5 and K2O are relatively concentrated in fine-grained sediments. However, Na2O and TiO2 are inde pendent from sediment types. The results of correlation and R-factor analysis suggested that the distribution of major element in the surface sediments from the offshore area of Shandong Peninsula can be classified to three groups. The first group consists of SiO2 .Al2O3 .Fe2O3 .MgO.K2O.TiO2 .P2O5 .TOC, the second includes CaO and CaCO3, and Na2O and MnO belong to the last groups. These three groups may probably represent terrigenous, marine biogenous and marine authigenic sediments respectively. The chemical weathering index of the surface sediments varies from 50-65, depending upon their provenance. The CIA and TiO2/Al2O3 values suggest that the Huanghe sediments are mainly deposited along the offshore area of Shandong Peninsula, controlled by the coastal currents and the sea bottom geomorphology.
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
2012年第3期45-54,共10页
Marine Geology & Quaternary Geology
基金
"我国近海海洋综合调查与评价"专项(908-01-CJ05)
海洋公益性行业科研专项(200805063-5)
黄土与第四纪地质国家重点实验室开放基金项目(SKLLQG1107)
国家自然科学基金项目(40976036
40506013
40906033)
关键词
常量元素
物源
山东半岛
黄河
major element
provenance
Huanghe
Shandong Peninsula
