Shahid Beheshti University Researches in Earth Sciences 2008-8299 10 2 2019 05 22 Magmatic origin of Th-REE mineralization at the Se-Chahun ore deposit: based on geochemical and stable isotope data Magmatic origin of Th-REE mineralization at the Se-Chahun ore deposit: based on geochemical and stable isotope data 213 227 97045 10.52547/esrj.10.2.213 FA Gholamreza Mirzababaei Ph.D in Economic Geology, Faculty of Earth Sciences, Shahid Beheshti University Mohammad Yazdi Professor, Faculty of Earth Sciences, Shahid Beheshti University Mohammad Qannadi Maragheh Professor, Nuclear Science and Technology Research Center, Atomic Energy Organization of Iran Mehrdad Behzadi Associate Professor, Faculty of Earth Sciences, Shahid Beheshti University Mohammad Reza Rezvanianzadeh Assistant Professor, Nuclear Science and Technology Research Center, Atomic Energy Organization of Iran Journal Article 2017 09 22 Examination of geochemical distribution pattern of trace and rare earth elements in the rocks affected by metasomatic processes revealed a magmatic origin for Th-REE mineralization at the Se-Chahun ore deposit. Chondrite and primitive mantle-normalized patterns of REE and trace elements for the rhyolitic host rocks (which formed in a subduction setting) compared with the patterns of the Th-REE mineralization zone also provides evidence that the origin of the Th-REE mineralization zone is similar with rhyolitic magma or a magmatic chamber from which the rhyolitic magma was originated. This is also supported by oxygen and hydrogen isotopic data in actinolite paragenetically associated with Th-REE bearing minerals. Thorium minerals at the Se Chahun ore deposit include huttonite and thorite. O and H isotopic data for actinolite paragenetically associated with Th-silicates revealed a magmatic source for Th-REE mineralizing fluids in the ore deposit δD and δ18O for actinolite paragenetically associated with Th silicates are calculated between -73.29 to -42.04 and 6.65 to 7.71, respectively, which lie within the field of magmatic fluids. Examination of geochemical distribution pattern of trace and rare earth elements in the rocks affected by metasomatic processes revealed a magmatic origin for Th-REE mineralization at the Se-Chahun ore deposit. Chondrite and primitive mantle-normalized patterns of REE and trace elements for the rhyolitic host rocks (which formed in a subduction setting) compared with the patterns of the Th-REE mineralization zone also provides evidence that the origin of the Th-REE mineralization zone is similar with rhyolitic magma or a magmatic chamber from which the rhyolitic magma was originated. This is also supported by oxygen and hydrogen isotopic data in actinolite paragenetically associated with Th-REE bearing minerals. Thorium minerals at the Se Chahun ore deposit include huttonite and thorite. O and H isotopic data for actinolite paragenetically associated with Th-silicates revealed a magmatic source for Th-REE mineralizing fluids in the ore deposit δD and δ18O for actinolite paragenetically associated with Th silicates are calculated between -73.29 to -42.04 and 6.65 to 7.71, respectively, which lie within the field of magmatic fluids. https://esrj.sbu.ac.ir/article_97045_2c24fb51cebf0a78f8b205d57482c3a6.pdf