青海沱沱河多才玛特大型Pb-Zn矿床——定位预测方法与找矿突破过程
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摘要
青海南部沱沱河地区的多才玛矿床是最近找矿突破发现的一个特大型铅锌矿床。由于赋矿规律不清,找矿方向不明,勘查曾一度陷入困境。针对制约找矿突破的关键地质问题,笔者开展了成矿潜力、矿床赋存规律、矿体定位预测研究,经钻探验证,实现了找矿突破。通过区域对比,认为沱沱河地区与"三江"带内兰坪等其他地区的地质背景相似,具有发育大型沉积岩容矿贱金属矿床的潜力;发现区域发育大型逆冲构造和含膏盐红层沉积、具有碳酸盐岩和暗色泥岩组合等,显示有利的成矿地质环境;区域和矿床内发育大规模高强度的铅锌化探异常,具有形成大型铅锌矿床的潜力。通过填图等研究,指出多才玛矿床为密西西比河谷型(MVT)矿床,产于逆冲推覆构造系统前锋带,矿体赋存于逆冲断裂上盘,受那益雄组碎屑岩和九十道班组灰岩岩相过渡部位及可能的逆冲推覆构造系统派生的反冲构造的控制,矿石主体为热液溶蚀角砾岩型。通过音频大地电磁测深测量,揭示了矿床深部物性特征和构造岩相特点,确定了孔莫陇矿段南侧深部铅锌矿化体的空间位置,并制定了钻探验证方案。经后期勘查,在预测区内探获了品位高、厚度大的铅锌矿体,使该矿段铅锌资源量由原来的76.2万吨增至259万吨,找矿取得重大突破。由此,通过综合分析,提出了一套综合地质、化探异常/矿化显示、地球物理、遥感等手段的多才玛式矿床定位预测方法组合。
The Duocaima ore deposit is a newly-found large Pb-Zn deposit in Tuotuohe area,Qinghai Province.Stu dies of mineral prospect evaluation,ore controls,and localization-prognosis were carried out to solve the key problems in the process of mineral exploration.Regional correlation suggests that the Tuotuohe area has similar geological setting to the regions in"Sanjiang belt"(e.g.Lanping basin) that host many large sediment-hosted Pb-Zn deposits.The geological settings during the mineralization,i.e.,thrust structure,sedimentation of red beds and development of carbonate adjacent to dark mudstone were favorable for Pb-Zn mineralization.In combination with extensive zinc-lead geochemical anomalies,the authors hold that the Duocaima area has good potential in search for large deposits.The Duocaima deposit is a carbonate-hosted,low-temperature,and epigenic deposit characterized by ores in breccia,no affinity with igneous activity,and involvement of sulfur generated by bacterial sulfate reduction,indicative of Mississippi Valley-type(MVT) origin.The ore body mainly occurs in fractured Permian limestone of the Jiushidaoban Formation(Pj) that is adjacent to Permian clastics of the Nayixiong Formation(Pn) and above a thrust fault.Audio magnetotelluric sounding measurements revealed resistivity distribution of several profiles,one of which determined the location of a potential underground ore body in southern Pj limestone of Kongmolong ore block.Based on these results,the authors successfully found thick and high-grade ore bodies,and Pb+Zn metal tonnages increased from 0.762 Mt to 2.59 Mt.The authors summarize the present and the previous studies and propose a mineral prospecting approach(integrated geolog-i cal,geochemical,geophysical,and remote-sensing methods) for exploiting Duocaima-like Pb-Zn deposits.
The Duocaima ore deposit is a newly-found large Pb-Zn deposit in Tuotuohe area,Qinghai Province.Stu dies of mineral prospect evaluation,ore controls,and localization-prognosis were carried out to solve the key problems in the process of mineral exploration.Regional correlation suggests that the Tuotuohe area has similar geological setting to the regions in"Sanjiang belt"(e.g.Lanping basin) that host many large sediment-hosted Pb-Zn deposits.The geological settings during the mineralization,i.e.,thrust structure,sedimentation of red beds and development of carbonate adjacent to dark mudstone were favorable for Pb-Zn mineralization.In combination with extensive zinc-lead geochemical anomalies,the authors hold that the Duocaima area has good potential in search for large deposits.The Duocaima deposit is a carbonate-hosted,low-temperature,and epigenic deposit characterized by ores in breccia,no affinity with igneous activity,and involvement of sulfur generated by bacterial sulfate reduction,indicative of Mississippi Valley-type(MVT) origin.The ore body mainly occurs in fractured Permian limestone of the Jiushidaoban Formation(Pj) that is adjacent to Permian clastics of the Nayixiong Formation(Pn) and above a thrust fault.Audio magnetotelluric sounding measurements revealed resistivity distribution of several profiles,one of which determined the location of a potential underground ore body in southern Pj limestone of Kongmolong ore block.Based on these results,the authors successfully found thick and high-grade ore bodies,and Pb+Zn metal tonnages increased from 0.762 Mt to 2.59 Mt.The authors summarize the present and the previous studies and propose a mineral prospecting approach(integrated geolog-i cal,geochemical,geophysical,and remote-sensing methods) for exploiting Duocaima-like Pb-Zn deposits.
引文
陈文,刘新宇,张彦,李洁,孙敬博.2012.风火山石英斑岩中透长石矿物学、成分及Ar-Ar年龄研究[J].矿物学报,增刊:16-17.
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李亚林,王成善,伊海生,刘志飞,李勇.2006.西藏北部新生代大型逆冲推覆构造与唐古拉山的隆起[J].地质学报,80:11181130.
李政.2008.青海省沱沱河地区茶曲帕查铅锌矿床的成因研究[D].北京:北京科技大学硕士论文.1-77.
刘长征,陈岳龙,许光,赵娟,李王月,李琳业,姬丙艳,汪元奎.2011.地球化学块体理论在青海沱沱河地区铅锌资源潜力预测中的应用[J].地学前缘,18(5):271-282.
刘英超.2012.青藏高原三江中段碳酸盐岩容矿铅锌矿床成矿特征与成因研究[D].北京:中国地质科学院博士论文.123-132.
牟传龙,王剑,余谦,张立生.1999.兰坪中新生代沉积盆地演化[J].矿物岩石,19(3):30-36.
宋玉财,侯增谦,杨天南,张洪瑞,田世洪,刘英超,王晓虎,刘燕学,薛传东,王光辉,李政.2011.“三江”喜山期沉积岩容矿贱金属矿床基本特征与成因类型[J].岩石矿物学杂志,30(3):355-380.
陶晓风,朱利东,刘登忠,王国芝,李佑国.2002.滇西兰坪盆地的形成及演化[J].成都理工学院学报,29(5):521-525.
王贵仁,宋玉财,邹公明,侯增谦,杨竹森,杨天南,张洪瑞,刘燕学,李政,汪元奎,刘群,然见多杰,赵呈祥,翟忠保.2012.青海南部茶曲帕查Pb-Zn矿床的勘查历史、现状与下一步找矿方向[J].岩石矿物学杂志,31(1):79-90.
张洪瑞,侯增谦,杨天南,宋玉财,李政,王召林,王晓虎,汪元奎,刘群.2010.青藏高原北羌塘南缘俯冲型石英正长斑岩的发现:来自地球化学分析证据[J].地质论评,56(3):403-412.
张洪瑞,杨天南,侯增谦,宋玉财,汪元奎,刘群.2011.三江北段茶曲帕查矿区构造变形与铅锌矿化[J].岩石矿物学杂志,30(3):463-474.
张洪瑞,杨天南,宋玉财,侯增谦,杨竹森,田世洪,刘英超,李连松,王贵仁,汪元奎,刘群.2012.古溶洞构造在青藏高原中部的发现及意义——以茶曲帕查铅锌矿床为例[J].矿床地质,31(3):449-458.
周江羽,王江海,Horton B,Yin A,Spurlin M.2011.青藏高原中东部古近纪盆地封闭的构造-沉积-岩浆活动和古气候响应[J].地质学报,85(2):172-178.
Bradley D C and Leach D L.2003.Tectonic controls of Mississippi Va-lley-type lead-zinc mineralization in orogenic forelands[J].Mineral-ium Deposita,38:652-667.
Corbella M,Ayora C and Cardellach E.2004.Hydrothermal mixing,carbonate dissolution and sulfide precipitation in Mississippi Valleytype deposits[J].Mineralium Deposita,39:344-357.
Ghazban F,McNutt R H and Schwarcz H P.1994.Genesis of sed-iment-hosted Zn-Pb-Ba deposits in the Irankuh district,Esfahanarea,west-central Iran[J].Econ.Geol.,89:1262-1278.
Hagni R D.1986.A summary of the geology of the ore deposits of theTr-i State district,Missouri,Kansas,and Oklahoma[C].Guidebookto the Geology and environmental concerns in the Tr-i State lead-zincdistrict,Missouri,Kansas,and Oklahoma:Association of MissouriGeologists,33rd annual field trip:30-46.
He L,Song Y,Chen K,Hou Z,Yu F,Yang Z,Wei J,Li Z and LiuY.2009.Thrust-controlled,sediment-hosted,Himalayan Zn-PbCu-Ag deposits in the Lanping foreland fold belt,eastern margin ofTibetan Plateau[J].Ore Geology Reviews,36(1-3):106-132.
Horton B K,Yin A,Spurlin M S,Zhou J Y and Wang J H.2002.Paleocene-Eocene syncontractional sedimentation in narrow,lacustrinedominated basins of east-central Tibet[J].Geological Society ofAmerica Bulletin,114:771-786.
Hou Z Q and Cook N J.2009.Metallogenesis of the Tibetan collisionalorogen:A review and introduction to the special issue[J].OreGeology Reviews,36:2-24.
Hou Z Q,Khin Z,Pan G T,Mo X X,Xu Q,Hu Y Z and Li X Z.2007.Sanjiang Tethyan metallogenesis in S.W.China:Tectonicsetting,metallogenic epochs and deposit types[J].Ore Geology Reviews,31:48-87.
Leach D L,Sangster D F,Kelley K D,Large R R,Garven G,Allen CR,Gutzmer J and Walters S.2005.Sediment-hosted lead-zinc deposits:A global prospective[J].Econ.Geol.,100th AnniversaryVolume:561-607.
Leach D L,Bradley D C,Huston D,Pisarevsky S A,Taylor R D andGardoll S J.2010.Sediment-hosted lead-zinc deposits in Earth history.Economic Geology,105(3):593-625.
Li Y L,WangC S,ZhaoXX,YinAandMaC.2012.Cenozoic thrust system,basin evolution,and uplift of the Tanggula Range in the Tuotuoheregion,central Tibet[J].Gondwana Research,22:482-492.
Misra K C.2000.Understanding Mineral Deposits[M].London:Kluwer Academic Publishers.573-612.
Spurlin M S,Yin A,Horton B K,Zhou J Y and Wang J H.2005.Structural evolution of the Yushu-Nangqian region and its relationship to syncollisional igneous activity,east-central Tibet[J].GSABulletin,117:1293-1317.
Wang J H,Yin A,Harrison T M,Grove M,Zhang Y and Xie G.2001.A tectonic model for Cenozoic igneous activities in the easternIndo-Asian collision zone[J].Earth and Planetary Science Letters,188:123-133.
Zhu L D,Wang C S,Zheng HB,Xiang F,Yi HS and Liu D Z.2006.Tectonic and sedimentary evolution of basins in the northeast ofQingha-i Tibet Plateau and their implication for the northwardgrowth of the plateau[J].Palaeogeography PalaeoclimatologyPalaeoecology,241(1):49-60.
侯增谦,宋玉财,李政,王召林,杨志明,杨竹森,刘英超,田世红,何龙清,陈开旭,王富春,赵呈祥,薛万文,鲁海峰.2008.青藏高原碰撞造山带Pb-Zn-Ag-Cu矿床新类型:成矿基本特征与构造控矿模型[J].矿床地质,27(2):123-144.
李亚林,王成善,伊海生,刘志飞,李勇.2006.西藏北部新生代大型逆冲推覆构造与唐古拉山的隆起[J].地质学报,80:11181130.
李政.2008.青海省沱沱河地区茶曲帕查铅锌矿床的成因研究[D].北京:北京科技大学硕士论文.1-77.
刘长征,陈岳龙,许光,赵娟,李王月,李琳业,姬丙艳,汪元奎.2011.地球化学块体理论在青海沱沱河地区铅锌资源潜力预测中的应用[J].地学前缘,18(5):271-282.
刘英超.2012.青藏高原三江中段碳酸盐岩容矿铅锌矿床成矿特征与成因研究[D].北京:中国地质科学院博士论文.123-132.
牟传龙,王剑,余谦,张立生.1999.兰坪中新生代沉积盆地演化[J].矿物岩石,19(3):30-36.
宋玉财,侯增谦,杨天南,张洪瑞,田世洪,刘英超,王晓虎,刘燕学,薛传东,王光辉,李政.2011.“三江”喜山期沉积岩容矿贱金属矿床基本特征与成因类型[J].岩石矿物学杂志,30(3):355-380.
陶晓风,朱利东,刘登忠,王国芝,李佑国.2002.滇西兰坪盆地的形成及演化[J].成都理工学院学报,29(5):521-525.
王贵仁,宋玉财,邹公明,侯增谦,杨竹森,杨天南,张洪瑞,刘燕学,李政,汪元奎,刘群,然见多杰,赵呈祥,翟忠保.2012.青海南部茶曲帕查Pb-Zn矿床的勘查历史、现状与下一步找矿方向[J].岩石矿物学杂志,31(1):79-90.
张洪瑞,侯增谦,杨天南,宋玉财,李政,王召林,王晓虎,汪元奎,刘群.2010.青藏高原北羌塘南缘俯冲型石英正长斑岩的发现:来自地球化学分析证据[J].地质论评,56(3):403-412.
张洪瑞,杨天南,侯增谦,宋玉财,汪元奎,刘群.2011.三江北段茶曲帕查矿区构造变形与铅锌矿化[J].岩石矿物学杂志,30(3):463-474.
张洪瑞,杨天南,宋玉财,侯增谦,杨竹森,田世洪,刘英超,李连松,王贵仁,汪元奎,刘群.2012.古溶洞构造在青藏高原中部的发现及意义——以茶曲帕查铅锌矿床为例[J].矿床地质,31(3):449-458.
周江羽,王江海,Horton B,Yin A,Spurlin M.2011.青藏高原中东部古近纪盆地封闭的构造-沉积-岩浆活动和古气候响应[J].地质学报,85(2):172-178.
Bradley D C and Leach D L.2003.Tectonic controls of Mississippi Va-lley-type lead-zinc mineralization in orogenic forelands[J].Mineral-ium Deposita,38:652-667.
Corbella M,Ayora C and Cardellach E.2004.Hydrothermal mixing,carbonate dissolution and sulfide precipitation in Mississippi Valleytype deposits[J].Mineralium Deposita,39:344-357.
Ghazban F,McNutt R H and Schwarcz H P.1994.Genesis of sed-iment-hosted Zn-Pb-Ba deposits in the Irankuh district,Esfahanarea,west-central Iran[J].Econ.Geol.,89:1262-1278.
Hagni R D.1986.A summary of the geology of the ore deposits of theTr-i State district,Missouri,Kansas,and Oklahoma[C].Guidebookto the Geology and environmental concerns in the Tr-i State lead-zincdistrict,Missouri,Kansas,and Oklahoma:Association of MissouriGeologists,33rd annual field trip:30-46.
He L,Song Y,Chen K,Hou Z,Yu F,Yang Z,Wei J,Li Z and LiuY.2009.Thrust-controlled,sediment-hosted,Himalayan Zn-PbCu-Ag deposits in the Lanping foreland fold belt,eastern margin ofTibetan Plateau[J].Ore Geology Reviews,36(1-3):106-132.
Horton B K,Yin A,Spurlin M S,Zhou J Y and Wang J H.2002.Paleocene-Eocene syncontractional sedimentation in narrow,lacustrinedominated basins of east-central Tibet[J].Geological Society ofAmerica Bulletin,114:771-786.
Hou Z Q and Cook N J.2009.Metallogenesis of the Tibetan collisionalorogen:A review and introduction to the special issue[J].OreGeology Reviews,36:2-24.
Hou Z Q,Khin Z,Pan G T,Mo X X,Xu Q,Hu Y Z and Li X Z.2007.Sanjiang Tethyan metallogenesis in S.W.China:Tectonicsetting,metallogenic epochs and deposit types[J].Ore Geology Reviews,31:48-87.
Leach D L,Sangster D F,Kelley K D,Large R R,Garven G,Allen CR,Gutzmer J and Walters S.2005.Sediment-hosted lead-zinc deposits:A global prospective[J].Econ.Geol.,100th AnniversaryVolume:561-607.
Leach D L,Bradley D C,Huston D,Pisarevsky S A,Taylor R D andGardoll S J.2010.Sediment-hosted lead-zinc deposits in Earth history.Economic Geology,105(3):593-625.
Li Y L,WangC S,ZhaoXX,YinAandMaC.2012.Cenozoic thrust system,basin evolution,and uplift of the Tanggula Range in the Tuotuoheregion,central Tibet[J].Gondwana Research,22:482-492.
Misra K C.2000.Understanding Mineral Deposits[M].London:Kluwer Academic Publishers.573-612.
Spurlin M S,Yin A,Horton B K,Zhou J Y and Wang J H.2005.Structural evolution of the Yushu-Nangqian region and its relationship to syncollisional igneous activity,east-central Tibet[J].GSABulletin,117:1293-1317.
Wang J H,Yin A,Harrison T M,Grove M,Zhang Y and Xie G.2001.A tectonic model for Cenozoic igneous activities in the easternIndo-Asian collision zone[J].Earth and Planetary Science Letters,188:123-133.
Zhu L D,Wang C S,Zheng HB,Xiang F,Yi HS and Liu D Z.2006.Tectonic and sedimentary evolution of basins in the northeast ofQingha-i Tibet Plateau and their implication for the northwardgrowth of the plateau[J].Palaeogeography PalaeoclimatologyPalaeoecology,241(1):49-60.