柴北缘绿梁山-双口山荒漠景观区风成沙对水系沉积物中成矿元素的干扰分析  

Interference analysis of eolian sand on ore-forming elements in the stream sediments in Desert Gobi Landscape of the Lvliangshan-Shuangkoushan region,northern margin of Qaidam

作　　者：徐永利[1] 孟明 王成彬[3] 

机构地区：[1]甘肃省地矿局第三地质矿产勘查院,甘肃兰州730050 [2]西部黄金伊犁有限责任公司,新疆伊犁835000 [3]中国地质大学资源学院,湖北武汉430074

出　　处：《地质学刊》2016年第4期604-614,共11页Journal of Geology

基　　金：中国地质调查局项目“青海省绿梁山-双口山地区矿产远景调查”(1212011121204)

摘　　要：青海绿梁山一双口山地区地处柴北缘成矿带，矿产资源丰富，找矿潜力巨大。该区具有典型的荒漠戈壁景观，广泛覆盖风成沙，而风成沙会掩盖水系沉积物中成矿元素的信息，严重影响野外找矿工作。通过划分构造景观区，开展风成沙粒级实验、水系沉积物粒级实验。研究发现，风成沙对绿梁山、双口山2个景观区内水系沉积物中成矿元素的影响程度不同：对前者中元素的影响系数接近1，对Cu、Cr、M、Co、Zn等元素的影响微弱，对Au、舷元素的影响中等；而对后者中元素的影响系数〉2，对船、Pb、Zn、Cr、Co、Ni等元素的影响较弱，对Au元素的影响极强。在绿梁山景观分区内，优选与Au、Cu等矿种有关的异常，选用0．3～4．0mm的采样粒级基本合理；优选与Cr、Ni、Co等矿种有关的异常，选用0．3～2．0mm的采样粒级是可靠的。在双口山景观分区内，圈定与Ph、Zn、舷等矿种有关的异常，选用0．3～4．0mm的采样粒级基本合理；圈定与Au矿种有关的异常，选用〉0．335mm的采样粒级可能是合理的。The Lvliangshan-Shuangkoushan region, which is located in the Noah Qaidam metallogenic belt in Qinghai Province, contains rich mineral resources and has a huge prospecting potential. It has a typical desert gobi landscape with widespread cover of eo- lian sand, which can weaken the ore-forming elements anomalies information contained in stream sediments and thus has brought a seri- ously negative influence on field prospecting. This study carried out size-fractionated experiments of eolian sand and stream sediments on the basis of structural landscape division. It is concluded that： （ 1 ） Eolian sand has a different influence on the distribution of ore- forming elements in stream sediments between Lvliangshan and Shuangkoushan landscape sub-regions. In the Lvliangshan landscape sub-region, aeolian sand brings a weak influence on Cu, Cr, Ni, Co and Zn and a moderate influence on Au and Ag, with an element influence coefficient close to 1 ; while it causes a weak influence on Ag, Pb, Zn, Cr, Co and Ni and a strong influence on Au, and has an element influence coefficient greater than 2 in the Shuangkoushan landscape sub-region. （2） In the Lvliangshan landscape sub-re- gion, it is reasonable and reliable to choose sampling grain sizes of 0.3 ~4.0 mm and 0.3- 2.0 mm to detect geochemical anomalies of Au-Cu deposits and Cr-Ni-Co deposits, respectively. （3） In the Shuangkoushan landscape sub-region, it is reasonable to select sam- piing sizes of 0.3-4.0 mm and 〉0.335 mm to detect geochemical anomalies of Pb-Zn-Ag deposits and Au deposits, respectively.

关 键 词：风成沙 水系沉积物 成矿元素 地球化学 干扰 柴北缘 青海 

分 类 号：P596[天文地球—地球化学]