TY - JOUR
T1 - Flood basalt-related Fe-Ti oxide deposits in the Emeishan large igneous province, SW China
AU - Pang, Kwan Nang
AU - Zhou, Mei Fu
AU - Qi, Liang
AU - Shellnutt, Gregory
AU - Wang, Christina Yan
AU - Zhao, Donggao
PY - 2010/9
Y1 - 2010/9
N2 - In the Panzhihua-Xichang region (Sichuan Province, SW China), there are a number of world-class magmatic Fe-Ti oxide deposits. They are hosted as conformable masses in lower parts of layered mafic-ultramafic intrusions that are part of the end-Guadalupian (~260Ma) Emeishan large igneous province. The ore-bearing Panzhihua, Hongge, Baima, Taihe and Xinjie intrusions are spatially and temporally associated with flood basalts and granitoids in the province. New mineralogical data for Fe-Ti oxide ores in the Hongge and Baima intrusions, combined with an overview of previously published data, provide a better understanding on the formation of these enigmatic deposits. Geochemical and Sr-Nd isotopic data confirm a genetic relation between the intrusions and high-Ti Emeishan flood basalts. Parental magma compositions, estimated using the most Mg-rich cumulus olivine in the intrusions, are characterized by slight to moderate degrees of fractionation (MgO=7.2-11wt.%). Occurrences of rare Cr-bearing titanomagnetite (Cr2O3=1.2-10.7wt.%) in the Panzhihua, Hongge and Xinjie intrusions are consistent with early crystallization of Fe-Ti oxides. Oxide-silicate equilibria and low V concentration (<4800ppm) in magnetite are consistent with relatively high oxygen fugacity. Flood basalt-related origin, early Fe-Ti oxide crystallization and relatively high oxygen fugacity, are characteristic of Fe-Ti oxide deposits in the Panxi region but are fundamentally different from those hosted in highly-differentiated, upper parts of large layered intrusions (e.g. the Bushveld Complex). Similar Fe-Ti oxide deposits have not been documented in other well-studied large igneous provinces to date, but a number of Fe-Ti oxide ore occurrences worldwide are potentially similar to this type of flood basalt-related oxide deposits.
AB - In the Panzhihua-Xichang region (Sichuan Province, SW China), there are a number of world-class magmatic Fe-Ti oxide deposits. They are hosted as conformable masses in lower parts of layered mafic-ultramafic intrusions that are part of the end-Guadalupian (~260Ma) Emeishan large igneous province. The ore-bearing Panzhihua, Hongge, Baima, Taihe and Xinjie intrusions are spatially and temporally associated with flood basalts and granitoids in the province. New mineralogical data for Fe-Ti oxide ores in the Hongge and Baima intrusions, combined with an overview of previously published data, provide a better understanding on the formation of these enigmatic deposits. Geochemical and Sr-Nd isotopic data confirm a genetic relation between the intrusions and high-Ti Emeishan flood basalts. Parental magma compositions, estimated using the most Mg-rich cumulus olivine in the intrusions, are characterized by slight to moderate degrees of fractionation (MgO=7.2-11wt.%). Occurrences of rare Cr-bearing titanomagnetite (Cr2O3=1.2-10.7wt.%) in the Panzhihua, Hongge and Xinjie intrusions are consistent with early crystallization of Fe-Ti oxides. Oxide-silicate equilibria and low V concentration (<4800ppm) in magnetite are consistent with relatively high oxygen fugacity. Flood basalt-related origin, early Fe-Ti oxide crystallization and relatively high oxygen fugacity, are characteristic of Fe-Ti oxide deposits in the Panxi region but are fundamentally different from those hosted in highly-differentiated, upper parts of large layered intrusions (e.g. the Bushveld Complex). Similar Fe-Ti oxide deposits have not been documented in other well-studied large igneous provinces to date, but a number of Fe-Ti oxide ore occurrences worldwide are potentially similar to this type of flood basalt-related oxide deposits.
KW - Emeishan
KW - Fe-Ti oxide ore
KW - Flood basalt
KW - Layered intrusion
KW - Panxi
UR - http://www.scopus.com/inward/record.url?scp=77956456778&partnerID=8YFLogxK
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U2 - 10.1016/j.lithos.2010.06.003
DO - 10.1016/j.lithos.2010.06.003
M3 - Article
AN - SCOPUS:77956456778
VL - 119
SP - 123
EP - 136
JO - Lithos
JF - Lithos
SN - 0024-4937
IS - 1-2
ER -