河北大庙Fe-Ti-P矿床中铁钛磷灰岩的成因:来自磷灰石的证据
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摘要
铁钛磷灰岩仅由磷灰石和铁钛氧化物组成,常赋存于岩体型斜长岩中,成因上有不混溶和分异堆晶两种不同的认识。本文从磷灰石角度讨论河北大庙铁钛磷灰岩的形成机制。大庙铁钛磷灰岩常产出于浸染状Fe-P矿体内部,有时与块状铁矿石交互出现形成韵律条带状矿石,为岩浆结晶分异的产物。铁钛磷灰岩中磷灰石呈浑圆状,含量变化于15%～34%。铁钛磷灰岩的全岩和磷灰石微量元素分析显示,磷灰石比全岩相对富集稀土元素达2.96～6.93倍,但两者的配分型式基本平行。质量平衡计算(R∝1/F)的结果表明,铁钛磷灰岩中几乎100%的稀土元素赋存于磷灰石中。综合上述特征,反映磷灰石为结晶分离的堆晶矿物,铁钛磷灰岩应为堆晶成因。因为如果磷灰石结晶于铁钛磷灰岩不混溶熔体,它的稀土元素分配系数也不会变化达2.3倍(变化于2.96～6.93)。计算出该磷灰石的母岩浆稀土元素组成,与浸染状Fe-P矿石最为相似,结合它与铁钛磷灰岩之间紧密共生的野外特征以及相似的全岩及磷灰石稀土元素配分型式,认为磷灰石最可能是在浸染状Fe-P矿浆中,经结晶分离作用形成铁钛磷灰岩。
Nelsonites,which consist essentially of Fe-Ti oxides and apatite,are spatially and temporally associated with Proterozoic massif-type anorthosites,and have been interpreted as either cumulate rocks or the products of immiscible melts.The Damiao anorthosite massif in Hebei Province in China,contains numerous disseminated and vein-type Fe-Ti oxide and apatite orebodies.The disseminated ores are hosted in homogeneous silicate rocks,whereas the vein-like bodies occur as veins,lenses and rhythmic layers of massive Fe-Ti oxides±apatite that are in sharp contact with the host anorthosite or norite.Here we provide new trace element data on individual apatite crystals and whole-rock samples of the host nelsonites of the Damiao anorthosite massif and use these data to investigate the mechanism of apatite accumulation in these rocks.Apatites in all analyzed nelsonites from Damiao are enriched in REE relative to the whole-rock samples by factors of 2.96 to 6.93,but both have parallel chondrite-normalized REE patterns.Mass-balance calculations (theoretical calculated curve R∝1/F) confirms that the whole-rock REE concentrations of nelsonites are nearly 100% controlled by the apatite.This finding strongly suggests that the apatites are cumulus minerals,because if the nelsonites were derived from an immiscible liquid,the apatite D_(REE) value (ratio of REE in apatite and whole-rock) would not show such large variations. Calculated melts in equilibrium with the cumulus apatite,have right-dip chrondrite-normalized REE patterns with small negative Eu and Ce anomalies and (Yb/Lu)_N<1.These melts are similar in composition to the disseminated Fe-P ores in Damiao,suggesting that the disseminated ores may represent the parental magma.This interpretation is supported by the fact that the nelsonites are usually associated with disseminated Fe-P ores,and by the similarity of the apatite and whole-rock REE patterns.
Nelsonites,which consist essentially of Fe-Ti oxides and apatite,are spatially and temporally associated with Proterozoic massif-type anorthosites,and have been interpreted as either cumulate rocks or the products of immiscible melts.The Damiao anorthosite massif in Hebei Province in China,contains numerous disseminated and vein-type Fe-Ti oxide and apatite orebodies.The disseminated ores are hosted in homogeneous silicate rocks,whereas the vein-like bodies occur as veins,lenses and rhythmic layers of massive Fe-Ti oxides±apatite that are in sharp contact with the host anorthosite or norite.Here we provide new trace element data on individual apatite crystals and whole-rock samples of the host nelsonites of the Damiao anorthosite massif and use these data to investigate the mechanism of apatite accumulation in these rocks.Apatites in all analyzed nelsonites from Damiao are enriched in REE relative to the whole-rock samples by factors of 2.96 to 6.93,but both have parallel chondrite-normalized REE patterns.Mass-balance calculations (theoretical calculated curve R∝1/F) confirms that the whole-rock REE concentrations of nelsonites are nearly 100% controlled by the apatite.This finding strongly suggests that the apatites are cumulus minerals,because if the nelsonites were derived from an immiscible liquid,the apatite D_(REE) value (ratio of REE in apatite and whole-rock) would not show such large variations. Calculated melts in equilibrium with the cumulus apatite,have right-dip chrondrite-normalized REE patterns with small negative Eu and Ce anomalies and (Yb/Lu)_N<1.These melts are similar in composition to the disseminated Fe-P ores in Damiao,suggesting that the disseminated ores may represent the parental magma.This interpretation is supported by the fact that the nelsonites are usually associated with disseminated Fe-P ores,and by the similarity of the apatite and whole-rock REE patterns.
引文
① 卢冰.1995． 大庙斜长岩及其中赋存的黑山铁磷矿床的地球化学(博士后出站报告).广州:中国科学院广州地球化学研究所
① 曹亚文.1988． 河北承德大庙斜长岩体及铁磷矿床的成因研究(硕士论文).导师:陈正,岳树勤,陈殿芬北京:中国地质科学院
Ashwal LD.1993． Anorthosites.Minerals and Rocks,21． Berlin,Heidelberg:Springer Verlag,83-218
Charlier B,Skar O,Korneliussen A,Duchesne JC and Vander Auwera J.2007． Ilmenite composition in the Tellnes Fe-Ti deposit,SW Norway:Fractional crystallization,postcumulus evolution and ilmenite-zircon relation.Contributions to Mineralogy and Petrology,154:119-134
Charlier B,Sakoma E,Sauve M,Stanaway K,Vander Auwera J and Duchesne JC.2008． The Grader layered intrusion (Havre-Saint-Pierre anorthosite Quebec) and genesis of nelsonite and other Fe-Ti-P ores.Lithos,101:359-378
Chen W,Zhao TP and Xu YH.2007． The chemical composition of Fe-Ti oxides from Damiao Fe-Ti-P deposit:Implication for the genesis of nelsonite.Acta Mineralogica Sinica,27 (Suppl):248-250 (in Chinese with English abstract)
Darling RS and Florence FP.1995． Apatite light rare earth element chemistry of the Port Leyden nelsonite,Adirondack Highlands,New York:Implications for the origin of nelsonite in anorthosite suite rocks.Economic Geology,90:964-968
Duchesne JC and Charlier B.2005． Geochemistry of cumulates from the Bjerkreim-Sokndal layered intrusion (S.Norway).Part Ⅰ:Constraints from major elements on the mechanism of cumulate formation and on the jotunite liquid line of descent.Lithos,83:229-254
Duchesne JC.1999． Fe-Ti deposit in Rogaland anorthosites (South Norway):Geochemical characteristic and problems of interpretation.Mineralium Deposita,34:182-198
Dymek RF and Owens BE.2001． Petrogenesis of apatite-rich rocks (nelsonites and oxide-apatite gabbronorite) associated with massif anorthosite.Economic Geology,96:797-815
Emslie RF.1975． Major rock units of the Morin Complex,Southweatern Quebec.Geological Survey of Canada Paper,74-48:37
Force ER.1991． The geology of titanium-mineral deposits.Geological Society of America Special Paper,259:112
Hu SL,Wang SS,Sang HQ,Qiu J,Ye DH,Chui RH and Qi CM.1990． The isotopic ages and REE geochemistry of Damiao anorthosite and their geological implication.Scientia Geologica Sinica,4:332-343 (in Chinese with English abstract)
Lindsley DH.2003． Do Fe-Ti oxide magma exist?Geology:Yes;Experiment:No! NGU Special Publication,9:34-35
McLelland J,Ashwal LD and Moore L.1994． Composition and petrogenesis of oxide-,apatite-rich gabbronorites associated with Proterozoic massif anorthosites:Examples from the Adirondack Moutains,New York.Contributions to Mineralogy and Petrology,116:225-238
Owens BE and Dymek RF.1992． Fe-Ti-P-rich rocks and massif anorthosite:Problems of interpretation illustrated from the Labrieville and St-Urbain plutons,Quebec.Canadian Mineralogist,30:163-190
Philpotts AR.1967． Origin of certain iron-titanium oxide and apatite rocks.Economic Geology,62:303-315
Qi L,Hu J and Gregoire DC.2000． Determination of trace elements in granites by inductively coupled plasma-mass spectrometry.Talanta,51:507-513
Roelandts I and Duchesne JC.1979． Rare earth elements in apatite from layered norites and iron-titanium oxide ore-bodies related to anorthosites (Rogaland,S.W.Norway).In:Ahrens LH (ed.).Origin and distribution of the elements.Physics and Chemistry of the Earth,11:119-212
Sun SS and McDonough WF.1989． Chemical and isotopic systematics of oceanic basalts implications for mantle composition and process.In:Saunders AD and Nony MJ (eds.).Magmatism in the Ocean Basin.Geological Society Special Publication,42:313-354
Wang GY.1979． The features of rocks and ore deposit in Chengde massif-anothosite in Hebei Province.Hebei Geological Information,(4) :1-28 (in Chinese with English abstract)
Watson TL.1907． Mineral resources of Virginia:Virginia Jamestown Exposition Commission,Lynchburg,Va.J.P.Bell.,618
Xie GH and Wang JW.1988． A preliminary study on the emplacement age of the Damiao anorthosite complex.Geochimica,1:13-17 (in Chinese with English abstract)
Xie GH.2005． The petrology and geochemistry of Damiao massifanorthosite and Miyun rapakivi-granite:Involving discussion on distribution and significance of global massif-anorthosite and rapakivi granite.Beijing:Science Press,92-172 (in Chinese)
Xue JY,Zhang FS and Hu MS.1988． The formation mechanism and cooling history of a type of anti-perthite.Acta Petrologica Sinica,(4) :22-28 (in Chinese with English abstract)
Ye DH,Yang QW and Xing JR.1996． The Damiao anorthosite and vanadic-titano magnetite and apatite deposits associated with the anorthosite in Chengde,Hebei.Field Trip Guide T216． 30th international geological congress,Beijing,China,August
Zhai YS.1965． The characteristic and petrogenesis of a anorthosite.Geological Review,23 (3) :186-195 (in Chinese with English abstract)
Zhang SH,Liu SW,Zhao Y,Yang JH,Song B and Liu XM.2007． The 1． 75～1． 68 Ga anorthosite-mangerite-alkali granitoid-rapakivi granite suite from the northern North China Craton:Magmatism related to a Paleoproterozoic orogen.Precambrian Research,155:287-312
Zhao TP,Chen FK,Zhai MG and Xia B.2004． Single zircon U-Pb ages and their geological significance of the Damiao anorthosite complex,Hebei Province,China.Acta Petrologica Sinica,20 (3) :685-690 (in Chinese with English abstract)
Zhou YC and Yuan C.1989． The REE geochemistrical characteristics of Damiao anorthosite complex and hosted Fe-P deposit.Journal of Changchun university of Earth Sciences,19 (1) :43-53 (in Chinese with English abstract)
陈伟,赵太平,徐勇航.2007． 大庙Fe-Ti-P矿床中铁钛磷灰岩的成因:来自铁钛氧化物矿物化学的证据.矿物学报,27(增刊):248-250
胡世玲,王松山,桑海清,裘翼,叶东虎,崔人合,戚长谋.1990． 大庙斜长岩同位素地质年龄、稀土地球化学及其地质意义.地质科学,4:332-342
解广轰,王俊文.1988． 大庙斜长岩杂岩体侵位年龄的初步研究.地球化学,1:13-17
解广轰.2005． 大庙斜长岩和密云环斑花岗岩的岩石学和地球化学:兼论全球岩体型斜长岩和环斑花岗岩类的时空分布及其意义.北京:科学出版社,92-172
王关玉.1979． 河北承德地区斜长岩体的岩石及矿床成矿特征.河北地质情报,(4) :1-28
薛纪越,张富生,胡梅生.1988． 一种反条纹长石的形成机制及其冷却历史.岩石学报,(4) :22-28
翟裕生.1965． 某斜长岩的岩石特征及成因.地质论评,23(3) :186-195
赵太平,陈福坤,翟明国,夏斌.2004． 河北大庙斜长岩杂岩体锆石U-Pb年龄及其地质意义.岩石学报,20:685-690
周永昶,袁朝.1989． 大庙斜长岩杂岩体及铁磷矿的稀土元素地球化学研究.长春地质学院学报,19(1) :43-53
① 曹亚文.1988． 河北承德大庙斜长岩体及铁磷矿床的成因研究(硕士论文).导师:陈正,岳树勤,陈殿芬北京:中国地质科学院
Ashwal LD.1993． Anorthosites.Minerals and Rocks,21． Berlin,Heidelberg:Springer Verlag,83-218
Charlier B,Skar O,Korneliussen A,Duchesne JC and Vander Auwera J.2007． Ilmenite composition in the Tellnes Fe-Ti deposit,SW Norway:Fractional crystallization,postcumulus evolution and ilmenite-zircon relation.Contributions to Mineralogy and Petrology,154:119-134
Charlier B,Sakoma E,Sauve M,Stanaway K,Vander Auwera J and Duchesne JC.2008． The Grader layered intrusion (Havre-Saint-Pierre anorthosite Quebec) and genesis of nelsonite and other Fe-Ti-P ores.Lithos,101:359-378
Chen W,Zhao TP and Xu YH.2007． The chemical composition of Fe-Ti oxides from Damiao Fe-Ti-P deposit:Implication for the genesis of nelsonite.Acta Mineralogica Sinica,27 (Suppl):248-250 (in Chinese with English abstract)
Darling RS and Florence FP.1995． Apatite light rare earth element chemistry of the Port Leyden nelsonite,Adirondack Highlands,New York:Implications for the origin of nelsonite in anorthosite suite rocks.Economic Geology,90:964-968
Duchesne JC and Charlier B.2005． Geochemistry of cumulates from the Bjerkreim-Sokndal layered intrusion (S.Norway).Part Ⅰ:Constraints from major elements on the mechanism of cumulate formation and on the jotunite liquid line of descent.Lithos,83:229-254
Duchesne JC.1999． Fe-Ti deposit in Rogaland anorthosites (South Norway):Geochemical characteristic and problems of interpretation.Mineralium Deposita,34:182-198
Dymek RF and Owens BE.2001． Petrogenesis of apatite-rich rocks (nelsonites and oxide-apatite gabbronorite) associated with massif anorthosite.Economic Geology,96:797-815
Emslie RF.1975． Major rock units of the Morin Complex,Southweatern Quebec.Geological Survey of Canada Paper,74-48:37
Force ER.1991． The geology of titanium-mineral deposits.Geological Society of America Special Paper,259:112
Hu SL,Wang SS,Sang HQ,Qiu J,Ye DH,Chui RH and Qi CM.1990． The isotopic ages and REE geochemistry of Damiao anorthosite and their geological implication.Scientia Geologica Sinica,4:332-343 (in Chinese with English abstract)
Lindsley DH.2003． Do Fe-Ti oxide magma exist?Geology:Yes;Experiment:No! NGU Special Publication,9:34-35
McLelland J,Ashwal LD and Moore L.1994． Composition and petrogenesis of oxide-,apatite-rich gabbronorites associated with Proterozoic massif anorthosites:Examples from the Adirondack Moutains,New York.Contributions to Mineralogy and Petrology,116:225-238
Owens BE and Dymek RF.1992． Fe-Ti-P-rich rocks and massif anorthosite:Problems of interpretation illustrated from the Labrieville and St-Urbain plutons,Quebec.Canadian Mineralogist,30:163-190
Philpotts AR.1967． Origin of certain iron-titanium oxide and apatite rocks.Economic Geology,62:303-315
Qi L,Hu J and Gregoire DC.2000． Determination of trace elements in granites by inductively coupled plasma-mass spectrometry.Talanta,51:507-513
Roelandts I and Duchesne JC.1979． Rare earth elements in apatite from layered norites and iron-titanium oxide ore-bodies related to anorthosites (Rogaland,S.W.Norway).In:Ahrens LH (ed.).Origin and distribution of the elements.Physics and Chemistry of the Earth,11:119-212
Sun SS and McDonough WF.1989． Chemical and isotopic systematics of oceanic basalts implications for mantle composition and process.In:Saunders AD and Nony MJ (eds.).Magmatism in the Ocean Basin.Geological Society Special Publication,42:313-354
Wang GY.1979． The features of rocks and ore deposit in Chengde massif-anothosite in Hebei Province.Hebei Geological Information,(4) :1-28 (in Chinese with English abstract)
Watson TL.1907． Mineral resources of Virginia:Virginia Jamestown Exposition Commission,Lynchburg,Va.J.P.Bell.,618
Xie GH and Wang JW.1988． A preliminary study on the emplacement age of the Damiao anorthosite complex.Geochimica,1:13-17 (in Chinese with English abstract)
Xie GH.2005． The petrology and geochemistry of Damiao massifanorthosite and Miyun rapakivi-granite:Involving discussion on distribution and significance of global massif-anorthosite and rapakivi granite.Beijing:Science Press,92-172 (in Chinese)
Xue JY,Zhang FS and Hu MS.1988． The formation mechanism and cooling history of a type of anti-perthite.Acta Petrologica Sinica,(4) :22-28 (in Chinese with English abstract)
Ye DH,Yang QW and Xing JR.1996． The Damiao anorthosite and vanadic-titano magnetite and apatite deposits associated with the anorthosite in Chengde,Hebei.Field Trip Guide T216． 30th international geological congress,Beijing,China,August
Zhai YS.1965． The characteristic and petrogenesis of a anorthosite.Geological Review,23 (3) :186-195 (in Chinese with English abstract)
Zhang SH,Liu SW,Zhao Y,Yang JH,Song B and Liu XM.2007． The 1． 75～1． 68 Ga anorthosite-mangerite-alkali granitoid-rapakivi granite suite from the northern North China Craton:Magmatism related to a Paleoproterozoic orogen.Precambrian Research,155:287-312
Zhao TP,Chen FK,Zhai MG and Xia B.2004． Single zircon U-Pb ages and their geological significance of the Damiao anorthosite complex,Hebei Province,China.Acta Petrologica Sinica,20 (3) :685-690 (in Chinese with English abstract)
Zhou YC and Yuan C.1989． The REE geochemistrical characteristics of Damiao anorthosite complex and hosted Fe-P deposit.Journal of Changchun university of Earth Sciences,19 (1) :43-53 (in Chinese with English abstract)
陈伟,赵太平,徐勇航.2007． 大庙Fe-Ti-P矿床中铁钛磷灰岩的成因:来自铁钛氧化物矿物化学的证据.矿物学报,27(增刊):248-250
胡世玲,王松山,桑海清,裘翼,叶东虎,崔人合,戚长谋.1990． 大庙斜长岩同位素地质年龄、稀土地球化学及其地质意义.地质科学,4:332-342
解广轰,王俊文.1988． 大庙斜长岩杂岩体侵位年龄的初步研究.地球化学,1:13-17
解广轰.2005． 大庙斜长岩和密云环斑花岗岩的岩石学和地球化学:兼论全球岩体型斜长岩和环斑花岗岩类的时空分布及其意义.北京:科学出版社,92-172
王关玉.1979． 河北承德地区斜长岩体的岩石及矿床成矿特征.河北地质情报,(4) :1-28
薛纪越,张富生,胡梅生.1988． 一种反条纹长石的形成机制及其冷却历史.岩石学报,(4) :22-28
翟裕生.1965． 某斜长岩的岩石特征及成因.地质论评,23(3) :186-195
赵太平,陈福坤,翟明国,夏斌.2004． 河北大庙斜长岩杂岩体锆石U-Pb年龄及其地质意义.岩石学报,20:685-690
周永昶,袁朝.1989． 大庙斜长岩杂岩体及铁磷矿的稀土元素地球化学研究.长春地质学院学报,19(1) :43-53
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