苦橄岩和科马提岩都是富镁的超镁铁质火山岩，早先，学术界大多关注它们之间的相似性，而对于它们之间的差异性很少强调。于是认为二者的地球化学性质近似，成因类似，形成条件类似。本文采用全数据模式的研究方法，从数据库收集了全球...苦橄岩和科马提岩都是富镁的超镁铁质火山岩，早先，学术界大多关注它们之间的相似性，而对于它们之间的差异性很少强调。于是认为二者的地球化学性质近似，成因类似，形成条件类似。本文采用全数据模式的研究方法，从数据库收集了全球太古宙全部科马提岩和后太古宙全部苦橄岩数据，对比的结果表明，太古宙科马提岩与后太古宙苦橄岩完全不同，它们之间几乎没有可比性。科马提岩与苦橄岩，不仅地球化学特征不同，而且成因不同，形成条件不同，产出时代不同，源区组成也不同。这种不同，反映了太古宙和后太古宙不可能属于同样的构造体制。太古宙是火球时代，地球异常的热，主导的可能是静止盖幔构造（stagnant lid tectonics）；后太古宙是热球时代，地球相对冷了许多，主导的是板块构造（plate tectonics）。科马提岩在太古宙广泛出露，无需地幔柱模式；而苦橄岩在后太古宙很少出露，才真正需要地幔柱模式。展开更多
The Geza arc is an important part of the Sanjiang tectono-magmatic belt and is a newly discovered copper polymetallic ore concentration area in northwest Yunnan province,Southwest China.The area comprises numerous met...The Geza arc is an important part of the Sanjiang tectono-magmatic belt and is a newly discovered copper polymetallic ore concentration area in northwest Yunnan province,Southwest China.The area comprises numerous metal ore deposits,including one super-largedeposit,three large deposits,etc.The formation of these deposits was closely related to intermediate–acidic magmatic intrusions.Based on previous studies,the“big data”analysis technique was used for a comparative study of large geochemical datasets of granite related to ore-formation in the Geza porphyry copper deposit and global adakites.As a result,1313 element combinations and 127,765 overlap ratios were obtained.The results show that the Geza porphyry has similar geochemical characteristics to global adakites(the ratios of REE and Ga to major elements are in the range of global adakites).However,theCu,Mo,and Zn contents of the porphyry are significantly higher than those of global adakites,and the porphyry may,therefore,represent an end-member of the global range of adakite composition.In addition,the geochemistry of adakites associated with the porphyry copper deposits overlaps in part with that of global adakites,although most of the data lie outside of the range of global adakites(i.e.lowMn/Cu,Sr/Cu,Na/Cu,and Zr/Cu values,and high Th/Cu,Ba/Cu,Na/Mo,Rb/Mo,Th/Mo,Ta/Mo,Ba/Mo,Mn/Zn,and Ba/Znvalues).The samples with characteristics that deviate significantly from the geochemistry of global adakites show more advanced mineralization and alteration,and a stronger relationship with Cu and Momineralization.The results of geochemical data mining can be used as a prospecting indicator,and provide a new scientific basis for geological prospecting of the deep levels and per-iphery of the Geza Cu polymetallic ore belt.展开更多
文摘苦橄岩和科马提岩都是富镁的超镁铁质火山岩，早先，学术界大多关注它们之间的相似性，而对于它们之间的差异性很少强调。于是认为二者的地球化学性质近似，成因类似，形成条件类似。本文采用全数据模式的研究方法，从数据库收集了全球太古宙全部科马提岩和后太古宙全部苦橄岩数据，对比的结果表明，太古宙科马提岩与后太古宙苦橄岩完全不同，它们之间几乎没有可比性。科马提岩与苦橄岩，不仅地球化学特征不同，而且成因不同，形成条件不同，产出时代不同，源区组成也不同。这种不同，反映了太古宙和后太古宙不可能属于同样的构造体制。太古宙是火球时代，地球异常的热，主导的可能是静止盖幔构造（stagnant lid tectonics）；后太古宙是热球时代，地球相对冷了许多，主导的是板块构造（plate tectonics）。科马提岩在太古宙广泛出露，无需地幔柱模式；而苦橄岩在后太古宙很少出露，才真正需要地幔柱模式。
基金This paper is supported by the Key Laboratory of Geological Information Technology,Ministry of Natural Resources of the People’s Repbulic of China[Grant No:KKF0201821043]Natural Science Foundation of China[Grant No.41862009]+1 种基金Science and Technology Award of Yunnan Province-Outstanding Contribution award Project[Grant No.2007001]Key disciplines construction funding project of Kunming University of Science and Technology[1407839305].
文摘The Geza arc is an important part of the Sanjiang tectono-magmatic belt and is a newly discovered copper polymetallic ore concentration area in northwest Yunnan province,Southwest China.The area comprises numerous metal ore deposits,including one super-largedeposit,three large deposits,etc.The formation of these deposits was closely related to intermediate–acidic magmatic intrusions.Based on previous studies,the“big data”analysis technique was used for a comparative study of large geochemical datasets of granite related to ore-formation in the Geza porphyry copper deposit and global adakites.As a result,1313 element combinations and 127,765 overlap ratios were obtained.The results show that the Geza porphyry has similar geochemical characteristics to global adakites(the ratios of REE and Ga to major elements are in the range of global adakites).However,theCu,Mo,and Zn contents of the porphyry are significantly higher than those of global adakites,and the porphyry may,therefore,represent an end-member of the global range of adakite composition.In addition,the geochemistry of adakites associated with the porphyry copper deposits overlaps in part with that of global adakites,although most of the data lie outside of the range of global adakites(i.e.lowMn/Cu,Sr/Cu,Na/Cu,and Zr/Cu values,and high Th/Cu,Ba/Cu,Na/Mo,Rb/Mo,Th/Mo,Ta/Mo,Ba/Mo,Mn/Zn,and Ba/Znvalues).The samples with characteristics that deviate significantly from the geochemistry of global adakites show more advanced mineralization and alteration,and a stronger relationship with Cu and Momineralization.The results of geochemical data mining can be used as a prospecting indicator,and provide a new scientific basis for geological prospecting of the deep levels and per-iphery of the Geza Cu polymetallic ore belt.
