R6: Plutonic rocks, volcanic rocks and subduction factory

[R6-09] Petrological and geochemical studies of igneous rocks in the Nidar ophiolite complex, northwest India

[Presentation award entry]

*Akinori Sato¹, Takeshi Imayama¹, Dutta Dripta², Yasuaki Kaneda³, Shota Watanabe³, Takeshi Hasegawa³, Masayo Minami⁴, Yuki Wakasugi⁴, Shigeyuki Wakaki⁵ (1. Okayama Univ Sci., 2. IIT Bombay., 3. Ibaraki univ., 4. Nagoya univ., 5. Kochi JAMSTEC)

Keywords:Nidar ophiolite, subduction initiation, petrology, geochemistry

The early Cretaceous Nidar Ophiolite complex is exposed in Ladakh, NW India. Arc-type dolerite and basalt yield flat REE patterns, whereas MORB-type gabbro has low REE concentrations and depleted LREE content. These igneous rocks have depleted Nd isotopic ratio. Combined with previous studies, the ophiolite in Ladakh formed by magmatism during seafloor spreading at the subduction initiation, followed by island arc tholeiitic to island arc calc-alkaline magmatism as the subduction zone developed.