University of Isfahan Petrological Journal 2228-5210 9 2 2018 08 23 Study of specifications of the second index Baba-Ali,‎unusual magnetite-limonite layered deposit ‎‎(Hamedan province)‎ Study of specifications of the second index Baba-Ali,‎unusual magnetite-limonite layered deposit ‎‎(Hamedan province)‎ 101 122 22833 10.22108/ijp.2018.103702.1028 FA Mehrdad Barati همدان - دانشگاه بوعلی سینا- دانشکده علوم پایه- گروه زمین شناسی Laila Karimian Navid Geology Dep.science faclty.Bu-Ali Sina uni. Hamedan.Iran Meisam Gholipoor Geology Dep, Science faclty, Bu-Ali Sina university, hamedan, Iran Journal Article 2017 04 26 Baba Ali Index 2, iron deposit is located in the northwest of Hamedan province and the southwestern of Baba Ali village in the Sanandaj-Sirjan structural zone. According to the field and microscopic studies, host rocks are including acid to intermediate igneous rocks, schists and skarns. Magnetite-limonite layers are the main ore minerals in this deposit. Limonite layers are unusual in the iron deposits. Limonite in polished sections is found in layer shape and magnetite replacement. Geochemical measurements was performed on magnetite and limonite samples by ICP-MS methods. Correlation and classification diagrams and REE parameters were calculated for geochemistry coditions. According to drown diagrams this index is c IOCG-type and skarn sub-type deposit. Mineralized fluids has injected into host rocks, mixed with layered limestone xenoliths and magnetite has been percipitated and replaced at the high temperature in oxidized condition. Magnetite altered to limonite by Re-injecte hydrothermal fluids. Limonite has been deposited as an initial phase by hydrothermal fluids in large volumes and with the replacement of primary layerd carbonate xenoliths and unusual sequence of magnetite- limonite layers has created in this deposit. Baba Ali Index 2, iron deposit is located in the northwest of Hamedan province and the southwestern of Baba Ali village in the Sanandaj-Sirjan structural zone. According to the field and microscopic studies, host rocks are including acid to intermediate igneous rocks, schists and skarns. Magnetite-limonite layers are the main ore minerals in this deposit. Limonite layers are unusual in the iron deposits. Limonite in polished sections is found in layer shape and magnetite replacement. Geochemical measurements was performed on magnetite and limonite samples by ICP-MS methods. Correlation and classification diagrams and REE parameters were calculated for geochemistry coditions. According to drown diagrams this index is c IOCG-type and skarn sub-type deposit. Mineralized fluids has injected into host rocks, mixed with layered limestone xenoliths and magnetite has been percipitated and replaced at the high temperature in oxidized condition. Magnetite altered to limonite by Re-injecte hydrothermal fluids. Limonite has been deposited as an initial phase by hydrothermal fluids in large volumes and with the replacement of primary layerd carbonate xenoliths and unusual sequence of magnetite- limonite layers has created in this deposit. https://ijp.ui.ac.ir/article_22833_0537a022bf9a292e78627f7ee72c2060.pdf