摘要
文章以河北省岩石和水系沉积物地球化学调查成果为基础,讨论了省内铅锌矿源层、地球化学块体的空间分布范围以及地球化学块体与矿源层的关系,旨在为研究区内的铅锌矿产勘查提供指导。研究结果表明,以高于该地区表壳岩石铅锌元素丰度的重要矿床的围岩作为铅锌矿源层的判别标志,侏罗纪、白垩纪火山-沉积岩及燕山期侵入岩、遵化岩群、红旗营子岩群等可确定为铅锌矿源层。以25μg/g为异常下限,圈定出水系沉积物铅地球化学块体7处;以100μg/g为异常下限,圈定出水系沉积物锌地球化学块体4处。在铅锌地球化学块体的内部及边缘,有多处大、中型铅锌矿床产出。在丰宁、围场一带出现大范围的铅元素连续成片的岩石高背景分布,锌元素的岩石高背景分布则位于崇礼和围场地区,铅锌高背景区主要分布于侏罗系-白垩系分布区内。侵入岩铅锌高背景区主要集中在乌龙沟-上黄旗岩浆岩带、军都山岩浆岩带及马兰峪复背斜东、西两端。经研究发现,据水系沉积物所圈定出的异常与铅锌矿床分布的一致性要好于据岩石所圈定的异常。在一个地球化学块体分布范围内,存在着多种地质体,而其中对异常形成贡献最大者可能是矿源层和矿床。矿源层与地球化学块体都强调其在成矿作用中是物质的供应源,不同之处在于,前者与矿床关系更紧密,而后者则与成矿省关系比较密切。
Some problems such as the lead-zinc source beds, the distribution of geochemical blocks and the relationship between geochemical blocks and source beds are discussed in this paper based on rock and stream sediment geochemical survey in Hebei Province. Studies show that the Jurassic and Cretaceous volcano-sedimentary rocks, Yanshanian intrusive rocks, and Zunhua Rock Group as well as Hongqiyingzi Rock Group can be regarded as lead-zinc source beds. The threshold of the Pb and Zn geochemical block is 25 μg/g and 100 μg/g. Seven lead and four zinc stream sediment geochemical blocks have been delineated, which host a cluster of lead-zinc ore deposits. Lead lithogeochemical high background is distributed in Fengning-Weichang area, and zinc lithogeochemical high background in Congli and Weichang areas. The consistency of lead-zinc deposits distribution suggests that stream sediment geochemical anomalies are better than rock geochemical anomalies. It is also considered that a geochemical block could contain a variety of geological bodies, in which mineralization source beds and Pb-Zn deposits make the main contribution to geochemical anomalies. Source beds and geochemical blocks both emphasize the role of material supply source in the formation of ore deposits, but the difference is that the former has a close relationship with the deposits, whereas the latter has a close relationship with the metallogenic province. These results are useful to the exploration of lead and zinc deposits in Hebei Province.
出处
《矿床地质》
CAS
CSCD
北大核心
2010年第2期276-282,共7页
Mineral Deposits
基金
全国矿产资源潜力评价项目(国土资发[2007]6号文件)的资助
关键词
地球化学
铅锌
矿源层
地球化学块体
地球化学异常
河北省
geochemistry
lead-zinc
source bed
geochemical block
geochemical anomaly
Hebei Province
