日照市海滩沉积物地球化学元素特征及物源研究

海滩是大自然赋予人类宝贵的自然资源，作为著名的海滨旅游城市，日照市拥有丰富的海滩资源。目前，国内对日照市海滩沉积物地球化学特征和物源的研究相对薄弱，掌握海滩沉积物特征对后续海滩保护、海洋管理和滨海旅游业的发展具有重要意义。本文对日照市自北向南4 个海滩5 个探槽所采集的73 个海滩样品，进行了沉积物粒度、常微量和稀土元素测试分析，系统地研究了日照市海滩沉积物的地球化学元素在平面上的变化特征与其物质来源。结果显示，日照市海滩沉积物普遍较粗，以粗砂和中砂为主，自北向南沉积物呈现细-粗-细的变化特征。常量元素以二氧化硅（SiO2） 为主，其次为三氧化二铝（Al2O3） 和氧化钾（K2O）、氧化钠（Na2O）、氧化钙（CaO） 等；微量元素以钡（Ba）、锶（Sr）、锆（Zr） 为主；稀土元素呈现明显的轻稀土元素富集、重稀土元素亏损，球粒陨石标准化曲线呈现左高右低的“V”形曲线，铕（Eu） 异常变化范围较大，从正异常-负异常，无明显铈（Ce） 异常。通过与长江、黄河及周边中小型入海河流沉积物的稀土元素对比分析，发现研究区内沉积物物质来源较复杂，主要为陆源物质，受到黄河及周边中小河流的影响程度较高。

Geochemical Elements Characteristics and Provenance Research of Sediments from Rizhao Beach

In this paper, sediment particle size, major elements and rare earth elements of 73 samples were measured and analyzed based on the samples collected from 4 beach exploratory trenches from north to south in Rizhao City. The variation characteristics and provenance of geochemical elements in beach sediments in Rizhao City were systematically studied. According to the results, the beach sediments in Rizhao City were generally coarse, mainly coarse sand and medium sand, and the sediments presented the characteristics of fine-coarsefine from north to south. The main major elements were SiO2, followed by Al2O3, K2O, Na2O and CaO, etc. The trace elements mainly were Ba, Sr and Zr. The rare earth elements showed obvious enrichment of light rare earth elements and deficit of heavy rare earth elements. And the standardized curve of chondrite of rare earth element showed a V-shaped curve with left high and right low. The range of Eu anomalies varied widely, from positive anomalies to negative anomalies, with no obvious Ce anomalies. Through the comparative analysis of rare earth elements in the sediments of the Yangtze River, the Yellow River and the surrounding small and medium-sized rivers entering the sea, it was found that the sediment provenance were complex, mainly were terrigenous matters, and were highly influenced by the Yellow River and the surrounding small and medium-sized rivers.