The Tobrne panel is the third of the Ta＇fba phosphate deposit. This mineralogical study contributes to the improved knowledge of the various facies that comprise the phosphate series of Tobrne. Based on X-ray diffrac...The Tobrne panel is the third of the Ta＇fba phosphate deposit. This mineralogical study contributes to the improved knowledge of the various facies that comprise the phosphate series of Tobrne. Based on X-ray diffraction results, the Tobrne panel yielded minerals that are primarily divided into four groups： minerals of the original phosphate phase： apatite, fluorapatite; carbonate minerals： calcite and dolomite; clay minerals： palygorskite, smectite, kaolinite and illite; minerals of altered facies： alteration minerals （analcime, millisite, crandallite and wavellite） and ferruginous minerals （goethite and gibbsite）. This succession of mineralogical associations reflects a polyphase alteration leading to a vertical and lateral facies sequence. This alteration intensifies the phosphate series upward and laterally from West to East.展开更多
The Tobène deposit forms, with those of NdomorDiop and KeurMor Fall, the large phosphate deposit of Ta?ba. The Tobène site has been the subject of lithostratigraphic, biostratigraphic, mineralogical, petrogr...The Tobène deposit forms, with those of NdomorDiop and KeurMor Fall, the large phosphate deposit of Ta?ba. The Tobène site has been the subject of lithostratigraphic, biostratigraphic, mineralogical, petrographic and geochemical studies. The lithostratigraphic and biostratigraphic studies dated the series from Lutetian to Bartonian composed of five lithological units, which are assembled by [1] in three formations. The mineralogical study shows three groups of minerals associated with the different phosphatic facies identified in the various sectors of Tobène: 1) characteristic minerals of sedimentological conditions;2) minerals of diagenetic origin;3) minerals of alteration. The petrographic study allowed an inventory of the constituting visible grains of the microfacies as well as the different phases of diagenetic and post-diagenetic transformations that may have affected them. It thus appears that the phosphatic ore of Tobène has undergone an extensive diagenesis (compaction, dissolution-recrystallization, epigenesis) to which a relatively intense ferruginization has been added.展开更多
文摘The Tobrne panel is the third of the Ta＇fba phosphate deposit. This mineralogical study contributes to the improved knowledge of the various facies that comprise the phosphate series of Tobrne. Based on X-ray diffraction results, the Tobrne panel yielded minerals that are primarily divided into four groups： minerals of the original phosphate phase： apatite, fluorapatite; carbonate minerals： calcite and dolomite; clay minerals： palygorskite, smectite, kaolinite and illite; minerals of altered facies： alteration minerals （analcime, millisite, crandallite and wavellite） and ferruginous minerals （goethite and gibbsite）. This succession of mineralogical associations reflects a polyphase alteration leading to a vertical and lateral facies sequence. This alteration intensifies the phosphate series upward and laterally from West to East.
文摘The Tobène deposit forms, with those of NdomorDiop and KeurMor Fall, the large phosphate deposit of Ta?ba. The Tobène site has been the subject of lithostratigraphic, biostratigraphic, mineralogical, petrographic and geochemical studies. The lithostratigraphic and biostratigraphic studies dated the series from Lutetian to Bartonian composed of five lithological units, which are assembled by [1] in three formations. The mineralogical study shows three groups of minerals associated with the different phosphatic facies identified in the various sectors of Tobène: 1) characteristic minerals of sedimentological conditions;2) minerals of diagenetic origin;3) minerals of alteration. The petrographic study allowed an inventory of the constituting visible grains of the microfacies as well as the different phases of diagenetic and post-diagenetic transformations that may have affected them. It thus appears that the phosphatic ore of Tobène has undergone an extensive diagenesis (compaction, dissolution-recrystallization, epigenesis) to which a relatively intense ferruginization has been added.
