【作者】 薛杉；

【导师】 王平；

【作者基本信息】 长安大学 ， 矿产普查与勘探， 2008， 硕士

【摘要】 陕西旬北盆地中部地区是秦岭中重要成矿带之一,成矿地质条件优越。近十几年来,陕西省地质一队相继发现和评价了泗人沟、关子沟、南沙沟和黄石板等一批中型铅锌矿床,旬北盆地志留系已经成为很有前景的铅锌矿集区（宋小文等,2003）。因此,有必要深化对旬北盆地志留系地层中铅锌矿成矿地质条件和成矿规律的认识,查明矿区内主要铅锌矿床的地质特征和成矿条件。通过全面收集旬北盆地内现有资料,进行系统的分析整理以及对研究区的野外地质考察,进而分析总结旬北盆地中部地区铅锌矿床地质特征。在查明铅锌矿床地质特征的基础上,通过分析其控矿条件,进一步对其研究区铅锌矿床成因进行初步探讨。研究结果表明,旬北盆地中部下古生界中的铅锌矿床主要产于志留系中梅子垭组、双河镇组和水洞沟组之内,矿体形态简单,为层状和似层状,矿石结构简单,矿物成分单一,围岩蚀变弱且不对称。含矿层与下覆和上覆岩层之间显示基本连续沉积性质,并表现出层序特点。矿床的形成与热水沉积岩关系密切,热水沉积岩以钠长石岩和硅质岩为主。根据对矿物包裹体的研究,矿床的成矿温度主要为225—275℃,属中低温条件。成矿流体的化学成分主要以K⁺、Na⁺、Ca²⁺、Mg²⁺、SO₄⁽2-_、Cl^-、F^-为主,且Na⁺>K⁺>Ca²⁺>Mg²⁺,反映矿床原生成因是沉积或地下热卤水成因。同位素和稀土元素研究表明,成矿金属元素主要来自于下伏沉积柱,成矿流体来自于海水。根据研究结果,认为研究区矿床为产于细碎屑岩中的热水沉积—改造型矿床,热水沉积成矿作用是旬北盆地下古生界铅锌矿床形成的主要成因。更多还原

【Abstract】 The central part of Xunbei basin is one of the important ore belts in Shaanxi province with superior metallogenic condition. In recent years, geologist have gradually found and accessed some lead-zinc deposits such as siren ditch, guanzi ditch, nansha ditch and yellow stone, ect. Topology of stay in Xunbei basin has becomes a prosperity ore concentration area. So it is necessary to increase the knowledge of metallogenic condition and law in lead-zinc ore, which is in the stratum of the topology of stay in Xunbei basin, and investigate the character and metallogenic condition in the main lead-zinc deposit.Through a comprehensive collection of information available in the North Basin, they worked with a systematic analysis and a geological study in the study area, then analyzed the features of the lead-zinc deposits in the central part of Northern Basin. Analysis its ore-control condition based on the features of lead-zinc deposit, and then discusses the reason of it in their study area.From the results, these lead-zinc deposits are mainly come from the the Silurian in Meiziya group, shuanghezhen Group and the water tunnel. The simple shape is stratified and stratoid beds with simple structure ores, monotone mineral composition, and rock alteration weak with asymmetric.The rock between the up and down deposits displays the property of continuous sediment and characteristics of sequences. There is a close relationship between formation of deposit and hot water sedimentary rocks, which mainly consist of albitite and cherts oriented. According to the study of mineral inclusions, the deposit for the main mineralization temperature is 225-275℃, which belongs to the low-temperature conditions. The mainly chemical composition of ore-forming fluids is K⁺,Na⁺,Ca²⁺,Mg²⁺,SO₄^2-,Cl^-,F^-, and Na⁺> K⁺> Ca²⁺> Mg²⁺, reflecting the deposit is generated by thermal deposition or underground brine causes. REE and isotope studies show that mineralization metal elements are mainly from the underlying sediment column, and mineralization fluid is from the sea.Based on the results, we consider that the deposit in the study area is produced by the hot water sedimentary from the pieces of rocks. Hot water sediment mineralization is the main reason of lead-zinc deposit underneath the Xunbei Basin Paleozoic.更多还原