马达加斯加石墨矿床控矿构造特征与找矿模型
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摘要
马达加斯加石墨矿床主要分布于马达加斯加岛中东部及南部,矿床类型丰富且成矿地质条件优越,具有良好的找矿前景。综合研究表明,石墨矿床成矿作用经历了自新太古代至新元古代沉积、变质变形及岩浆叠加改造三个阶段。控矿构造研究表明,中部石墨矿床主要受由于紧密同斜褶皱改造的变质片理构造控制,矿体翼部薄而转折端较厚。东部石墨矿床受同斜褶皱及顺变质片理的剪切带控制,并被后期沿脆性断裂迁移的热液叠加富集。南部石墨矿床由于受深层次剪切变形带的影响而延伸稳定。在控矿构造研究的基础上,提出针对石墨矿床"层带复合-岩浆叠加"为主体的区域找矿模型。结合已有矿化时空分布规律及成矿条件,提出了马达加斯加4个主要的成矿远景区。
Madagascar graphite deposits are mainly distributed in the Middle-East and south of Madagascar Island. There are abundant types of graphite deposits and favorable metallogenic geological conditions in this area,which have good prospecting prospects. The comprehensive study shows that the metallogenesis of graphite deposits has gone through three stages: Neoarchean to Neoproterozoic sedimentation,metamorphic deformation and magmatic superimposition and transformation. The study of ore-controlling structure shows that the central graphite deposit is mainly controlled by metamorphic schistosity transformed by tight isoclinal folds,with thin wings and thick hinge zone. The eastern graphite deposits are controlled by shear zones of synclinal folds and metamorphic schistosities,and are enriched by hydrothermal superimposition of later migration along brittle faults. The southern graphite deposit extends steadily due to the influence of deep shear deformation zone. Based on the study of ore-controlling structures,a regional prospecting model for graphite deposits is proposed,in which the main body is "zonal composite-magmatic superimposition ". Based on the existing spatial and temporal distribution of mineralization and metallogenic conditions, four major metallogenic prospects in Madagascar are divided in this paper.
Madagascar graphite deposits are mainly distributed in the Middle-East and south of Madagascar Island. There are abundant types of graphite deposits and favorable metallogenic geological conditions in this area,which have good prospecting prospects. The comprehensive study shows that the metallogenesis of graphite deposits has gone through three stages: Neoarchean to Neoproterozoic sedimentation,metamorphic deformation and magmatic superimposition and transformation. The study of ore-controlling structure shows that the central graphite deposit is mainly controlled by metamorphic schistosity transformed by tight isoclinal folds,with thin wings and thick hinge zone. The eastern graphite deposits are controlled by shear zones of synclinal folds and metamorphic schistosities,and are enriched by hydrothermal superimposition of later migration along brittle faults. The southern graphite deposit extends steadily due to the influence of deep shear deformation zone. Based on the study of ore-controlling structures,a regional prospecting model for graphite deposits is proposed,in which the main body is "zonal composite-magmatic superimposition ". Based on the existing spatial and temporal distribution of mineralization and metallogenic conditions, four major metallogenic prospects in Madagascar are divided in this paper.
引文
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[8]杨喜安,刘善宝,王光良,等.马达加斯加Maevatanana金矿床构造控矿特征[J].黄金,2013,34(9):16-22.YANG Xi'an,LIU Shanbao,WANG Guangliang,et al.Characteristics of ore-controlling structure in Maevatanana gold deposit,Madagascar[J].Gold,2013,34(9):16-22.(in Chinese with English abstract)
[9]车继英,赵院冬,王奎良,等.马达加斯加前寒武纪变质基底特征综述[J].地质与资源,2013,22(4):340-346.CHE Jiying,ZHAO Yuandong,Wang Kuiliang,et al.Overview of the precambrian geology of Madagascar[J].Geology and Resources,2013,22(4):340-346.(in Chinese with English abstract)
[10]贾凤仪,赵永辉,杨本昭.“三位一体”找矿模型在金矿勘查中的应用---以陕西省汉阴县坝王沟金矿为例[J].地质力学学报,2016,22(2):185-198.JIA Fengyi,ZHAO Yonghui,YANG Benzhao.Application of the trinity prospecting model in gold exploration:An example From the Bawanggou gold deposit in Hanyin,Shaanxi[J].Journal of Geomechanics,2016,22(2):185-198.(in Chinese with English abstract)
[2]TUCKER R D,ROIG J Y,MACEY P H,et al.A new geological framework for south-central Madagascar,and its relevance to the“out-of-Africa”hypothesis[J].Precambrian Research,2011,185(3-4):109-130.
[3]NAWARATNE S W,DISSANAYAKE C B.Gold occurrences in Madagascar,South India and Sri Lanka:Significance of a possible Pan-African event[J].Gondwana Research,2001,4(3):367-375.
[4]COLLINS A S,RAZAKAMANANA T,WINDLEY B F.Neoproterozoic extensional detachment in central Madagascar:implications for the collapse of the East African Orogen[J].Geological Magazine,2000,137(1):39-51.
[5]COLLINS A S,WINDLEY B F.The tectonic evolution of central and northern Madagascar and its place in the final assembly of Gondwana[J].The Journal of Geology,2002,110(3):325-339.
[6]COLLINS A S,FITZSIMONS I C W,HULSCHER B,et al.Structure of the eastern margin of the East African Orogen in central Madagascar[J].Precambrian Research,2003,123(2-4):111-133.
[7]马君,刘剑平,潘校华,等.东、西非大陆边缘比较及其油气意义[J].成都理工大学学报(自然科学版),2009,36(5):538-545.MA Jun,LIU Jianping,PAN Xiaohua,et al.Geological characters of the East and West Africa continental margins and their significance for hydrocarbon exploration[J].Journal of Chengdu University of Technology(Science&Technology Edition),2009,36(5):538-545.(in Chinese with English abstract)
[8]杨喜安,刘善宝,王光良,等.马达加斯加Maevatanana金矿床构造控矿特征[J].黄金,2013,34(9):16-22.YANG Xi'an,LIU Shanbao,WANG Guangliang,et al.Characteristics of ore-controlling structure in Maevatanana gold deposit,Madagascar[J].Gold,2013,34(9):16-22.(in Chinese with English abstract)
[9]车继英,赵院冬,王奎良,等.马达加斯加前寒武纪变质基底特征综述[J].地质与资源,2013,22(4):340-346.CHE Jiying,ZHAO Yuandong,Wang Kuiliang,et al.Overview of the precambrian geology of Madagascar[J].Geology and Resources,2013,22(4):340-346.(in Chinese with English abstract)
[10]贾凤仪,赵永辉,杨本昭.“三位一体”找矿模型在金矿勘查中的应用---以陕西省汉阴县坝王沟金矿为例[J].地质力学学报,2016,22(2):185-198.JIA Fengyi,ZHAO Yonghui,YANG Benzhao.Application of the trinity prospecting model in gold exploration:An example From the Bawanggou gold deposit in Hanyin,Shaanxi[J].Journal of Geomechanics,2016,22(2):185-198.(in Chinese with English abstract)