It is quite evident that it is not anomalous metal transport,nor unique depositional conditions,nor any single factor at the deposit scale,that dictates whether a mineral deposit becomes a giant or not.A hierarchical ...It is quite evident that it is not anomalous metal transport,nor unique depositional conditions,nor any single factor at the deposit scale,that dictates whether a mineral deposit becomes a giant or not.A hierarchical approach thus is required to progressively examine controlling parameters at successively decreasing scales in the total mineral system to understand the location of giant gold deposits in non-arc environments.For giant orogenic,intrusion-related gold systems（IRGS） and Carlin-type gold deposits and iron oxide-copper-gold（IOCG） deposits,there are common factors among all of these at the lithospheric to crustal scale.All are sited in giant gold provinces controlled by complex fundamental fault or shear zones that follow craton margins or,in the case of most Phanerozoic orogenic giants,define the primary suture zones between tectonic terranes.Giant provinces of IRGS,IOCG,and Carlin-type deposits require melting of metasomatized lithosphere beneath craton margins with ascent of hybrid lamprophyric to granitic magmas and associated heat flux to generate the giant province.The IRGS and IOCG deposits require direct exsolution of volatile-rich magmatic-hydrothermal fluids,whereas the association of such melts with Carlin-type ores is more indirect and enigmatic.Giant orogenic gold provinces show no direct relationship to such magmatism.forming from metamorphic fluids,but show an indirect relationship to lamprophyres that reflect the mantle connectivity of controlling first-order structures.In contrast to their province scale similarities,the different giant gold deposit styles show contrasting critical controls at the district to deposit scale.For orogenic gold deposits,the giants appear to have formed by conjunction of a greater number of parameters to those that control smaller deposits,with resultant geometrical and lithostratigraphic complexity as a guide to their location.There are few giant IRGS due to their inferior fluid-flux systems relative to orogenic gold deposits,and those few giants are展开更多
The sediment hosted disseminated gold deposits in the Qinling region are of sedimentation slight metamorphic origin superimposed by hydrothermal reworking at moderate low temperatures and are well comparable with the ...The sediment hosted disseminated gold deposits in the Qinling region are of sedimentation slight metamorphic origin superimposed by hydrothermal reworking at moderate low temperatures and are well comparable with the typical Carlin gold deposits in the United States. In view of the confusing concept concerning the \!sediment hosted" and \!Carlin type" gold deposits, the authors propose that the term \!sediment hosted gold deposit" should be used in a broad sense which encompasses at least the four subtypes, i.e., the Carlin type, the metamorphic fine clastic type, the hydrothermal sedimentary type and the vein type. In other words, the \!Carlin type" should not be used as a synonym for \!sediment hosted" but is recommended as a subtype under the general category of \!sediment hosted gold deposits".展开更多
基金funded by Talent Award under the 1000 Plan Project from the Chinese Government
文摘It is quite evident that it is not anomalous metal transport,nor unique depositional conditions,nor any single factor at the deposit scale,that dictates whether a mineral deposit becomes a giant or not.A hierarchical approach thus is required to progressively examine controlling parameters at successively decreasing scales in the total mineral system to understand the location of giant gold deposits in non-arc environments.For giant orogenic,intrusion-related gold systems（IRGS） and Carlin-type gold deposits and iron oxide-copper-gold（IOCG） deposits,there are common factors among all of these at the lithospheric to crustal scale.All are sited in giant gold provinces controlled by complex fundamental fault or shear zones that follow craton margins or,in the case of most Phanerozoic orogenic giants,define the primary suture zones between tectonic terranes.Giant provinces of IRGS,IOCG,and Carlin-type deposits require melting of metasomatized lithosphere beneath craton margins with ascent of hybrid lamprophyric to granitic magmas and associated heat flux to generate the giant province.The IRGS and IOCG deposits require direct exsolution of volatile-rich magmatic-hydrothermal fluids,whereas the association of such melts with Carlin-type ores is more indirect and enigmatic.Giant orogenic gold provinces show no direct relationship to such magmatism.forming from metamorphic fluids,but show an indirect relationship to lamprophyres that reflect the mantle connectivity of controlling first-order structures.In contrast to their province scale similarities,the different giant gold deposit styles show contrasting critical controls at the district to deposit scale.For orogenic gold deposits,the giants appear to have formed by conjunction of a greater number of parameters to those that control smaller deposits,with resultant geometrical and lithostratigraphic complexity as a guide to their location.There are few giant IRGS due to their inferior fluid-flux systems relative to orogenic gold deposits,and those few giants are
文摘The sediment hosted disseminated gold deposits in the Qinling region are of sedimentation slight metamorphic origin superimposed by hydrothermal reworking at moderate low temperatures and are well comparable with the typical Carlin gold deposits in the United States. In view of the confusing concept concerning the \!sediment hosted" and \!Carlin type" gold deposits, the authors propose that the term \!sediment hosted gold deposit" should be used in a broad sense which encompasses at least the four subtypes, i.e., the Carlin type, the metamorphic fine clastic type, the hydrothermal sedimentary type and the vein type. In other words, the \!Carlin type" should not be used as a synonym for \!sediment hosted" but is recommended as a subtype under the general category of \!sediment hosted gold deposits".
文摘通过对贵州水银洞卡林型金矿苔藓植物野外全面调查,发现贵州水银洞金矿共有苔藓植物15科42属102种,其中苔类植物4科4属5种,藓类植物10科37属96种,角苔类植物1科1属1种。短柄小曲尾藓Dicranella gonoiCard.、纤毛丝瓜藓Pohlia hisaet.Kop et J.S.Lou、纤枝短月藓Brachymenium exile(Doz.et.Molk)Bosch et Lac.、真藓Bryum argenteumHedw.为该矿区裸地大量生长的种类,可利用它们作为金属矿山生态恢复进一步研究的素材。通过与露天开采的金矿区苔藓植物丰富度比较,埋藏型金矿区的苔藓植物较露天开采的金矿区的丰富。该区苔藓植物区系地理成分共9种,世界广布和中国特有分布占主要优势(各22种,都占21.57%),其次是东亚成分(共17种,都占16.67%),再次为热带亚洲成分(共16种,都占15.69%)。
