University of Isfahan Petrological Journal 2228-5210 7 28 2016 12 21 Petrogenesis of low Silica Adakitic domes of Sahl (South of Shahrood, southeast of Semnan Province) Petrogenesis of low Silica Adakitic domes of Sahl (South of Shahrood, southeast of Semnan Province) 95 108 21232 10.22108/ijp.2016.21232 FA Fazilat Yousefi Mahmoud Sadeghian دانشگاه صنعتی شاهرود - دانشکده علوم زمین Zahra Jamali Batoul Mansouri Moghadam Habibollah Ghasemi شاهرود- بلوار دانشگاه- دانشگاه صنعتی شاهرود- دانشکده علوم زمین Journal Article 2015 09 26 Sahl area, in the south of Shahrood, is a part of the northern portion of the Central Iran Structural Zone. The area is dominated by a thick sequence of the Paleocene to the middle Eocene volcanic and volcano-sedimentary rocks. Hypabyssal igneous rocks as dome, dike and sill with trachybasaltic andesite and trachyandesite composition intruded the sequence. Various enclaves with amphibolitic, gneissic, hornblenditic, pyroxenitic, tonalitic, gabbroic, tuffaceous sandstone and siltstone nature with different sizes and shapes are present in the rocks studied which can be taken as an evidence of contamination and magma mixing processes. With respect to geochemical characteristics, the studied rocks are belonging to low silica adakites , with calc-alkaline to high potassium calc-alkaline affinity, enriched in LREE and LILE and depleted in HREE and HSFE. Overall, the mentioned adakites resulted from crystallization of melts originated from partial melting of metasomatized or modified mantle wedge, above the subduction zone of the Neotethys oceanic slab (Sabzevar - Daruneh branch). Sahl area, in the south of Shahrood, is a part of the northern portion of the Central Iran Structural Zone. The area is dominated by a thick sequence of the Paleocene to the middle Eocene volcanic and volcano-sedimentary rocks. Hypabyssal igneous rocks as dome, dike and sill with trachybasaltic andesite and trachyandesite composition intruded the sequence. Various enclaves with amphibolitic, gneissic, hornblenditic, pyroxenitic, tonalitic, gabbroic, tuffaceous sandstone and siltstone nature with different sizes and shapes are present in the rocks studied which can be taken as an evidence of contamination and magma mixing processes. With respect to geochemical characteristics, the studied rocks are belonging to low silica adakites , with calc-alkaline to high potassium calc-alkaline affinity, enriched in LREE and LILE and depleted in HREE and HSFE. Overall, the mentioned adakites resulted from crystallization of melts originated from partial melting of metasomatized or modified mantle wedge, above the subduction zone of the Neotethys oceanic slab (Sabzevar - Daruneh branch). https://ijp.ui.ac.ir/article_21232_74afe8320965c582090dcd98550482ec.pdf