旬北盆地中部铅锌矿床地质特征及其成因初探
|
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~+、Ca~(2+)、Mg~(2+)、SO_4~(2-_、Cl~-、F~-为主,且Na~+>K~+>Ca~(2+)>Mg~(2+),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。
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~+,Ca~(2+),Mg~(2+),SO_4~(2-),Cl~-,F~-, and Na~+> K~+> Ca~(2+)> Mg~(2+), 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.
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~+、Ca~(2+)、Mg~(2+)、SO_4~(2-_、Cl~-、F~-为主,且Na~+>K~+>Ca~(2+)>Mg~(2+),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。
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~+,Ca~(2+),Mg~(2+),SO_4~(2-),Cl~-,F~-, and Na~+> K~+> Ca~(2+)> Mg~(2+), 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.
引文
[1]董王仓,南秦岭旬阳北部泥盆纪地层格架与盆地演化,陕西地质,1995,13(2);
[2]方维营,卢纪英,陕西银铜子—大西沟菱铁银多金属矿床热水沉积岩相特征及成因[J],沉积学报,2000,18(3):437~438;
[3]方维管,秦岭造山带中热水沉积成矿盆地的研究思路与方法初探—兼论秦岭超大型金属矿集区的研究与勘查[J],西北地质科学,1999,20(2),28—41;
[4]方维营,秦岭造山带古热水场地球化学类型及流体动力学模型探讨—热水沉积成矿盆地分析与研究方法之二[J],西北地质科学,1999,20(2),17—27;
[5]方维营,胡瑞忠,秦岭造山带大型一超大型矿床密集区构造定位与勘查新思路—热水沉积成矿盆地分析与研究方法之三[J],西北地质科学,2000,21(l);
[6]方维营,胡瑞忠等,热水沉积成矿盆地的热状态及热演化分析与研究—热水沉积成矿盆地分析与研究方法之四[J],西北地质科学,2000,21(l);
[7]方维营,秦岭造山带泥盆纪构造热水沉积成矿盆地与流体成岩成矿特征及其演化规律(博士学位论文),西北大学地质系,1999;
[8]方维营,秦岭造山带大型一超大型金属矿床形成大陆动力学条件分析[J],西北地质,1998,19(3):11—17;
[9]方维管,张国伟,胡瑞忠等,秦岭造山带泥盆系热水沉积岩相的亚相和微相划分及特征[J],地质与勘探,2001,37(2):50~54;
[10]方维聋,论流体与成矿作用[J],有色金属矿产与勘查,1999,8(2);
[11]樊益民、姜建超,陕西省镇(安)旬(阳)矿田主要控矿因素分析[J],秦巴地质论文集,第二集,1990;
[12]郭建,李作华等,陕西风太矿田同生断裂的确定及找矿方向[J],矿产与勘查,1990,(3);
[13]郭建,李作华,同生断裂在铅酮山矿区层控铅锌矿成矿中的作用[J],矿产与勘查,1989,6;
[14]贺菊瑞,巫全准等,火山断陷盆地的边缘成矿论[J],火山地质与矿产,1994,15(3);
[15]侯增谦等,现代海底热液成矿作用研究现状及发展方向,地学前缘(中国地质大学,北京),1996(3—4);
[16]胡建民,孟庆任,白武明等,南秦岭构造带中一晚古生代伸展构造作用,地质通报,2002,21(8—9):l—477;
[17]胡建民,赵国春,孟庆任等,武当地块基性侵入岩群的地质特征与构造意义,岩石学报,2003,19(4):601—611;
[18]黄月华,任有祥,夏林忻等,北大巴山早古生代双模式火山岩套:以高滩辉绿岩和篙坪粗面岩为例[J],岩石学报,1992,8(3):243—256;
[19]胡健民,赵国春,孟庆任等,武当地块基性侵入岩群的地质特征与构造意义[J],岩石学报,2003,19(4):601—611;
[20]胡建民,孟庆任,白武明等,南秦岭构造带中一晚古生代伸展构造作用[J],地质通报,2002,21(8—9):471—477;
[21]胡永和,朱兴盛,中国东南部中生代大陆边缘成矿体系和成矿模式[J],地质找矿论丛,1997,12(2);
[22]侯满堂,减世权等,镇旬铅锌矿田热水沉积硅质岩研究[J],陕西地质,2004,22(1);
[23]黄月华,任有祥,夏林忻等,北大巴山早古生代双模式火山岩套:以高滩辉绿岩和篙坪粗面岩为例[J],岩石学报,1992,8(3):243—256;
[24]黄书俊,曾永超,秦岭泥盆系层控铅锌矿床成因模式探讨[J],矿产与地质,1991,(3);
[25]胡明安,陕西柞水银洞子银铅多金属矿床的有机地球化学特征[J],地球科学,1990,15(l):34—55;
[26]胡西顺,陕西柞山地区钠长石碳酸盐角砾岩的地质特征与矿产,西北地质,1998,19(4);
[27]赖绍聪,张国伟,杨永成等,南秦岭勉县一略阳结合带蛇绿岩和岛弧火山岩地球化学及其大地构造意义[J],地球化学,1998,27(3):283—293;
[28]李春显,刘仰文等,秦岭及祁连山构造发展演化史,国际交流地质学术论文集(l),地质出版社,1978;
[29]刘丛强,黄智龙,李和平等,地慢流体及其成矿作用[J],地学前缘,2001,8(4):231—243;
[30]刘淑文,王涛,薛春纪,李秉新,南秦岭古生代隐伏基底分布特征及对金属成矿的控制[J],长安大学学报(地球科学版),2003,第25卷,第3期;
[31]刘建明,叶杰等,SEDXE型和VMHS型矿床及其成矿地球动力学背景的对比[J],矿床地质,2002,21(增刊);
[32]梁文艺,陕西凤太地区泥盆纪铅锌矿床形成与演化史及地质依据[J],西安地质学院学报,1985,7(l):38—49;
[33]李英,祁思敬,马国良,张振飞,中国北方超大型热水沉积硫化物矿床基本特征及形成条件研究[J],西安工程学院学报,1999,21(4):19—24;
[34]李英,西成矿田铅同位素组成及其成因意义[J],西北地质,1985,(6);
[35]李英,西成矿田层控铅锌矿床稳定同位素和包裹体研究[J],西安地质学院学报,1986,8(2);
[36]李发林,王瑞延,陈二虎,凤—太矿田大型铅锌矿床勘查靶区及其找矿思路[J],西北地质,2004,37(3);
[37]梁华英,王秀障,程景平,陕西双王钠长石岩特征及金矿床形成期次分析[J],大地构造与成矿学,2000,24(4):350—356;
[38]李勇,苏春乾,刘继庆,东秦岭造山带钠长岩的特征、成因及时代[J],岩石矿物学杂志,1999,18(2):122—127;
[39]李勇,周宗桂,陕西镇安—旬阳地区汞锑、铅锌、金矿床成因及演化规律浅析[J],地质与资源,2003,12(1);
[40]李厚民,祁思敬,陕西山阳小河口铜矿床地质特征及成因[A],祁思敬,李英,秦岭热水沉积型铅锌(铜)矿床,北京:地质出版社,1993,154—165;
[41]孟庆任,秦岭晚古生代沉积作用、盆地发展和构造演化[D],西安:西北大学博士论文,1994;
[42]祁思敬,李英,南秦岭晚古生代海底喷气—沉积成矿系统[J],地学前缘,1999,6(l):171—179;
[2]方维营,卢纪英,陕西银铜子—大西沟菱铁银多金属矿床热水沉积岩相特征及成因[J],沉积学报,2000,18(3):437~438;
[3]方维管,秦岭造山带中热水沉积成矿盆地的研究思路与方法初探—兼论秦岭超大型金属矿集区的研究与勘查[J],西北地质科学,1999,20(2),28—41;
[4]方维营,秦岭造山带古热水场地球化学类型及流体动力学模型探讨—热水沉积成矿盆地分析与研究方法之二[J],西北地质科学,1999,20(2),17—27;
[5]方维营,胡瑞忠,秦岭造山带大型一超大型矿床密集区构造定位与勘查新思路—热水沉积成矿盆地分析与研究方法之三[J],西北地质科学,2000,21(l);
[6]方维营,胡瑞忠等,热水沉积成矿盆地的热状态及热演化分析与研究—热水沉积成矿盆地分析与研究方法之四[J],西北地质科学,2000,21(l);
[7]方维营,秦岭造山带泥盆纪构造热水沉积成矿盆地与流体成岩成矿特征及其演化规律(博士学位论文),西北大学地质系,1999;
[8]方维营,秦岭造山带大型一超大型金属矿床形成大陆动力学条件分析[J],西北地质,1998,19(3):11—17;
[9]方维管,张国伟,胡瑞忠等,秦岭造山带泥盆系热水沉积岩相的亚相和微相划分及特征[J],地质与勘探,2001,37(2):50~54;
[10]方维聋,论流体与成矿作用[J],有色金属矿产与勘查,1999,8(2);
[11]樊益民、姜建超,陕西省镇(安)旬(阳)矿田主要控矿因素分析[J],秦巴地质论文集,第二集,1990;
[12]郭建,李作华等,陕西风太矿田同生断裂的确定及找矿方向[J],矿产与勘查,1990,(3);
[13]郭建,李作华,同生断裂在铅酮山矿区层控铅锌矿成矿中的作用[J],矿产与勘查,1989,6;
[14]贺菊瑞,巫全准等,火山断陷盆地的边缘成矿论[J],火山地质与矿产,1994,15(3);
[15]侯增谦等,现代海底热液成矿作用研究现状及发展方向,地学前缘(中国地质大学,北京),1996(3—4);
[16]胡建民,孟庆任,白武明等,南秦岭构造带中一晚古生代伸展构造作用,地质通报,2002,21(8—9):l—477;
[17]胡建民,赵国春,孟庆任等,武当地块基性侵入岩群的地质特征与构造意义,岩石学报,2003,19(4):601—611;
[18]黄月华,任有祥,夏林忻等,北大巴山早古生代双模式火山岩套:以高滩辉绿岩和篙坪粗面岩为例[J],岩石学报,1992,8(3):243—256;
[19]胡健民,赵国春,孟庆任等,武当地块基性侵入岩群的地质特征与构造意义[J],岩石学报,2003,19(4):601—611;
[20]胡建民,孟庆任,白武明等,南秦岭构造带中一晚古生代伸展构造作用[J],地质通报,2002,21(8—9):471—477;
[21]胡永和,朱兴盛,中国东南部中生代大陆边缘成矿体系和成矿模式[J],地质找矿论丛,1997,12(2);
[22]侯满堂,减世权等,镇旬铅锌矿田热水沉积硅质岩研究[J],陕西地质,2004,22(1);
[23]黄月华,任有祥,夏林忻等,北大巴山早古生代双模式火山岩套:以高滩辉绿岩和篙坪粗面岩为例[J],岩石学报,1992,8(3):243—256;
[24]黄书俊,曾永超,秦岭泥盆系层控铅锌矿床成因模式探讨[J],矿产与地质,1991,(3);
[25]胡明安,陕西柞水银洞子银铅多金属矿床的有机地球化学特征[J],地球科学,1990,15(l):34—55;
[26]胡西顺,陕西柞山地区钠长石碳酸盐角砾岩的地质特征与矿产,西北地质,1998,19(4);
[27]赖绍聪,张国伟,杨永成等,南秦岭勉县一略阳结合带蛇绿岩和岛弧火山岩地球化学及其大地构造意义[J],地球化学,1998,27(3):283—293;
[28]李春显,刘仰文等,秦岭及祁连山构造发展演化史,国际交流地质学术论文集(l),地质出版社,1978;
[29]刘丛强,黄智龙,李和平等,地慢流体及其成矿作用[J],地学前缘,2001,8(4):231—243;
[30]刘淑文,王涛,薛春纪,李秉新,南秦岭古生代隐伏基底分布特征及对金属成矿的控制[J],长安大学学报(地球科学版),2003,第25卷,第3期;
[31]刘建明,叶杰等,SEDXE型和VMHS型矿床及其成矿地球动力学背景的对比[J],矿床地质,2002,21(增刊);
[32]梁文艺,陕西凤太地区泥盆纪铅锌矿床形成与演化史及地质依据[J],西安地质学院学报,1985,7(l):38—49;
[33]李英,祁思敬,马国良,张振飞,中国北方超大型热水沉积硫化物矿床基本特征及形成条件研究[J],西安工程学院学报,1999,21(4):19—24;
[34]李英,西成矿田铅同位素组成及其成因意义[J],西北地质,1985,(6);
[35]李英,西成矿田层控铅锌矿床稳定同位素和包裹体研究[J],西安地质学院学报,1986,8(2);
[36]李发林,王瑞延,陈二虎,凤—太矿田大型铅锌矿床勘查靶区及其找矿思路[J],西北地质,2004,37(3);
[37]梁华英,王秀障,程景平,陕西双王钠长石岩特征及金矿床形成期次分析[J],大地构造与成矿学,2000,24(4):350—356;
[38]李勇,苏春乾,刘继庆,东秦岭造山带钠长岩的特征、成因及时代[J],岩石矿物学杂志,1999,18(2):122—127;
[39]李勇,周宗桂,陕西镇安—旬阳地区汞锑、铅锌、金矿床成因及演化规律浅析[J],地质与资源,2003,12(1);
[40]李厚民,祁思敬,陕西山阳小河口铜矿床地质特征及成因[A],祁思敬,李英,秦岭热水沉积型铅锌(铜)矿床,北京:地质出版社,1993,154—165;
[41]孟庆任,秦岭晚古生代沉积作用、盆地发展和构造演化[D],西安:西北大学博士论文,1994;
[42]祁思敬,李英,南秦岭晚古生代海底喷气—沉积成矿系统[J],地学前缘,1999,6(l):171—179;