【摘要】 <正> 山东半岛三面环水,伸入渤海、黄海之中,海岸线长达三千余公里,占我国岸线总长六分之一,陆架宽广,砂质海岸发育,为我国滨海砂矿远景储量较为丰富的地区之一、滨海砂矿形成的区域地质背景半岛区的构造位置处于新华夏系第二隆起带,区内广泛出露太古一元古代变质岩系,中新生代火山岩及第四纪松散沉积物,发育了以燕山期为主的侵入岩,该区总体长期抬升,基岩裸露、遭受风化剥蚀,为滨海重矿物的富集提供了丰富的物源.半岛面临开阔的渤海、黄海,水动力条件有利于重矿物富集.更多还原

【Abstract】 The coastal area of Shandong Peninsula is rich in Placer deposits. There the minerals are found as native gold, zirkon, titanite, rutile, and quartz. 12 ore deposits economically valuable are discovered and in addition, 70 localities of placer ore are reported. Geographically, the placers may be grouped into 4 ore districts, namely, the Yexian-Zhaoyuan gold placer district, the Rongcheng-Rizhao zircon-magnetite placer district, the Huangxian-Rongcheng glass making quartz sand district and the Yexian-Rizhao building quartz sand district. The distribution of the individual placer deposits is closely related to the extensively outcropped Indosinianenshanian intrusive bodies and the metamorphics of the Jiaodong Group in that the different rock produces the different placer. The placers occur chiefly in coastal plain -where they distribute along the seashore and constitute part of the littoral sand bars, spits, beaches but are also found in other Quaternary loose sediments such as terrace placer of rivers. The process of placer formation was multiphased but prevailed in Holocene. The genetic types recognized are residual of slope wash, alluvial, marine and aeolian, among which the marine-built type is most important.更多还原