R7: Petrology, Mineralogy and Economic geology (Joint Session with Society of Resource Geology)

[R7-10] Thermal structure of the oceanic crust as a proxy for the spreading rate: X-tal size geothermometer of the sheeted dikes in the Oman Ophiolite

*Susumu Umino¹, Ayumi Okugawa⁵, Atsushi Toramaru², Yuki Kusano³, Sumio Miyashita⁴, Yoshiko Adachi⁶, Akihiro Tamura¹, Tomoaki Morishita¹ (1. Kanazawa Univ., 2. Kyushu Univ., 3. AIST, 4. HRCG, 5. YKK, 6. CRIEPI)

Keywords:X-tal size geothermometer, Oman Ophiolite, crustal architecture, geotherm, spreading rate

Intra-segmental variations in crustal structure are closely related to the magma supply rate, which is highest in the center of the segment and lowest at the segment ends. Thus, the crust should be warmer at the center than at the ends. We apply grain-size thermometry to the sheeted dikes in the northern Oman Ophiolite and discuss the differences in thermal structure within the segment based on heat balance calculations.