CONTRASTING PARENTAL MAGMA COMPOSITIONS FOR THE HONGGE AND PANZHIHUA MAGMATIC Fe-Ti-V OXIDE DEPOSITS, EMEISHAN LARGE IGNEOUS PROVINCE, SW CHINA

Abstract

Research Article| September 01, 2014 CONTRASTING PARENTAL MAGMA COMPOSITIONS FOR THE HONGGE AND PANZHIHUA MAGMATIC Fe-Ti-V OXIDE DEPOSITS, EMEISHAN LARGE IGNEOUS PROVINCE, SW CHINA* Zhong-Jie Bai; Zhong-Jie Bai 1State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China Search for other works by this author on: GSW Google Scholar Hong Zhong; Hong Zhong † 1State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China †Corresponding author: e-mail, zhonghong@vip.gyig.ac.cn Search for other works by this author on: GSW Google Scholar Chusi Li; Chusi Li 2Department of Geological Sciences, Indiana University, Bloomington, Indiana 47405 Search for other works by this author on: GSW Google Scholar Wei-Guang Zhu; Wei-Guang Zhu 1State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China Search for other works by this author on: GSW Google Scholar De-Feng He; De-Feng He 1State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China Search for other works by this author on: GSW Google Scholar Liang Qi Liang Qi 1State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China Search for other works by this author on: GSW Google Scholar Economic Geology (2014) 109 (6): 1763–1785. https://doi.org/10.2113/econgeo.109.6.1763 Article history received: 29 Jul 2013 accepted: 03 Jan 2014 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Zhong-Jie Bai, Hong Zhong, Chusi Li, Wei-Guang Zhu, De-Feng He, Liang Qi; CONTRASTING PARENTAL MAGMA COMPOSITIONS FOR THE HONGGE AND PANZHIHUA MAGMATIC Fe-Ti-V OXIDE DEPOSITS, EMEISHAN LARGE IGNEOUS PROVINCE, SW CHINA. Economic Geology 2014;; 109 (6): 1763–1785. doi: https://doi.org/10.2113/econgeo.109.6.1763 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyEconomic Geology Search Advanced Search Abstract Many ~260 Ma mafic-ultramafic layered intrusions, including Hongge and Panzhihua, in the Emeishan large igneous province, southwestern China host world-class Fe-Ti-V oxide ore deposits. These two most important ore-bearing intrusions show differences in lithology and mineral chemistry. The most important orebodies in the Hongge intrusion occur as concordant layers in the middle part of the intrusion, closely associated with clinopyroxenites. Titanomagnetite and Mg-rich ilmenite are the major ore minerals of the Hongge deposit. Coexisting clinopyroxene contains >1.7 wt % TiO2. These data indicate high Ti parental magma for the Hongge ore-bearing clinopyroxenites. In the Panzhihua intrusion, the most important orebodies also occur as concordant layers but in its lower part instead of middle part. In contrast with the Hongge deposit, the most important host rocks of the Panzhihua deposit are gabbros, not clinopyroxenites. In addition, ilmenite is rare and titanomagnetite is predominant in the Panzhihua deposit. Coexisting clinopyroxene in the Panzhihua deposit contains <1.6 wt % TiO2. The contrasting lithologic and mineral compositions indicate that the parental magma for the Hongge deposit has higher TiO2 than that for the Panzhihua deposit. The compositions of clinopyroxene from the Panzhihua and Hongge deposits indicate that their parental magmas are also different in MgO/FeO and trace element ratios as well. Calculations using average experimental Mg-Fe exchange coefficient and trace element partition coefficients between clinopyroxene and magma show that the Hongge parental magma has higher MgO/FeO ratios and more fractionated mantle-normalized trace element patterns than the Panzhihua parental magma. The estimated compositions of the parental magmas for the Hongge and Panzhihua ore-bearing lithologies resemble the average compositions of the Longzhoushan-type high Ti basalts and Ertan-type intermediate Ti basalts in the Emeishan large igneous province, respectively. The new trace element data from this study, together with available Sr-Nd isotope data for the ore-bearing intrusions from literature, support a new petrogenetic model involving selective assimilation of newly subducted, stagnant oceanic gabbroic slab above the deep-seated Emeishan mantle plume. This process and subsequent contamination with the upper crust played an important role in the variation of parental magma compositions between the Hongge and Panzhihua magmatic oxide ore deposits. Abundant Fe-Ti oxide ore deposits associated with less evolved basaltic magma in the Emeishan large igneous province than elsewhere in the world are attributed to selective assimilation of newly subducted, stagnant oceanic lithospheric slab by the ascending mantle plume-derived picritic magma that was originally undersaturated with Fe-Ti oxides. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.