Magmatic Cu-Ni sulfide deposits are generally associated with mafic-ultramafic rocks and it has not been reported that lamprophyre is one of the surrounding rocks of Cu-Ni sulfide deposits.The Dhi Samir deposit in Yem...Magmatic Cu-Ni sulfide deposits are generally associated with mafic-ultramafic rocks and it has not been reported that lamprophyre is one of the surrounding rocks of Cu-Ni sulfide deposits.The Dhi Samir deposit in Yemen,however,is a rare example of Cu-Ni deposits which are hosted in lamprophyre dikes.In this paper,comprehensive research is made on petrology,petrochemistry and isotope geochemistry for Cu-Ni-bearing rocks in the Dhi Samir area and the results show that dark rocks related to Cu-Ni orebodies are sodium-weak potassium and belong to calc-alkaline series lamprophyre,especially camptonite,characterized by enriched alkali,iron and titanium.In these rocks large-ion-lithophile elements are obviously concentrated,while high field strength elements slightly depleted,showing clear negative anomalies of Ta and Nb,and weak deficiency of Ti.TheΣREE is very high（225.67-290.05 ppm） and the REE partition curves are flat and right-inclined,featuring a LREE-enriched pattern with low negative Eu anomalies.Study of magmatic source areas indicates that the rocks have low（87Sr/86Sr） and highεNd（t）,and the magmas were probably derived from the enriched mantle I（EM-I） end-member.Based on the LA-ICPMS on zircon U-Pb isotope dating,the lamprophyre in the Dhi Samir mining area has an age of 602±2.6 Ma,indicating that the rock was formed in the late Proterozoic and in an intraplate setting due to magmatism of an extensional environment in the post-Pan-Africa orogeny.展开更多
1.Objectives The Dhi Samir copper-nickel sulfide deposit is located in the Taiz Province, South Yemen. The ore-bearing rock bodies occurred in the Neoproterozoic magmatic veins (Fig. 1). Different from most magmatic c...1.Objectives The Dhi Samir copper-nickel sulfide deposit is located in the Taiz Province, South Yemen. The ore-bearing rock bodies occurred in the Neoproterozoic magmatic veins (Fig. 1). Different from most magmatic copper-nickel sulfide deposits, the Dhi Samir copper-nickel deposit is produced in the lamprophyre rather than in the mafic-ultramafic rocks such as peridotite, norite and gabbro.展开更多
Samir Amin que nous venons de perdre en ■ 2018fut un intellectuel et homme d'action qui aura consacréla majeure partie de sa vie au service d'un monde plus juste,en proposant une analyse stimulante pour ...Samir Amin que nous venons de perdre en ■ 2018fut un intellectuel et homme d'action qui aura consacréla majeure partie de sa vie au service d'un monde plus juste,en proposant une analyse stimulante pour servir notamment ■ l'émancipation de peuples du Sud de notre planète.Il fut un universitaire qui nous a léguéun nombre impressionnant de publications,en même temps qu’un intellectuel et un homme d'action engagédont l'uvre est largement reconnue.L'article présente quelques aspects de sa trajectoire de vie et les thèses essentielles qu'il a développées dans sesécrits.展开更多
文摘Magmatic Cu-Ni sulfide deposits are generally associated with mafic-ultramafic rocks and it has not been reported that lamprophyre is one of the surrounding rocks of Cu-Ni sulfide deposits.The Dhi Samir deposit in Yemen,however,is a rare example of Cu-Ni deposits which are hosted in lamprophyre dikes.In this paper,comprehensive research is made on petrology,petrochemistry and isotope geochemistry for Cu-Ni-bearing rocks in the Dhi Samir area and the results show that dark rocks related to Cu-Ni orebodies are sodium-weak potassium and belong to calc-alkaline series lamprophyre,especially camptonite,characterized by enriched alkali,iron and titanium.In these rocks large-ion-lithophile elements are obviously concentrated,while high field strength elements slightly depleted,showing clear negative anomalies of Ta and Nb,and weak deficiency of Ti.TheΣREE is very high（225.67-290.05 ppm） and the REE partition curves are flat and right-inclined,featuring a LREE-enriched pattern with low negative Eu anomalies.Study of magmatic source areas indicates that the rocks have low（87Sr/86Sr） and highεNd（t）,and the magmas were probably derived from the enriched mantle I（EM-I） end-member.Based on the LA-ICPMS on zircon U-Pb isotope dating,the lamprophyre in the Dhi Samir mining area has an age of 602±2.6 Ma,indicating that the rock was formed in the late Proterozoic and in an intraplate setting due to magmatism of an extensional environment in the post-Pan-Africa orogeny.
文摘1.Objectives The Dhi Samir copper-nickel sulfide deposit is located in the Taiz Province, South Yemen. The ore-bearing rock bodies occurred in the Neoproterozoic magmatic veins (Fig. 1). Different from most magmatic copper-nickel sulfide deposits, the Dhi Samir copper-nickel deposit is produced in the lamprophyre rather than in the mafic-ultramafic rocks such as peridotite, norite and gabbro.
文摘Samir Amin que nous venons de perdre en ■ 2018fut un intellectuel et homme d'action qui aura consacréla majeure partie de sa vie au service d'un monde plus juste,en proposant une analyse stimulante pour servir notamment ■ l'émancipation de peuples du Sud de notre planète.Il fut un universitaire qui nous a léguéun nombre impressionnant de publications,en même temps qu’un intellectuel et un homme d'action engagédont l'uvre est largement reconnue.L'article présente quelques aspects de sa trajectoire de vie et les thèses essentielles qu'il a développées dans sesécrits.
