[M-IS16] Drilling Earth Science

[MIS16-16] IODP Exp. 360 Preliminary reports: Indian Ridge Lower Crust and Moho at Slower Spreading Ridges (SloMo)

Henry J.B. Dick¹, Christopher MacLeod², Peter Blum³, *Natsue Abe⁴, Tomoaki Morishita⁵, Toshio Nozaka⁶, Alessio Sanfilippo^5,7, Scientific Party IODP Exp. 360³ (1.Woods Hole Oceanographic Institut, 2.Cardiff University, 3.Texas A & M University, 4.R&D Center for Ocean Drilling Science Japan Agency for Marine-Earth Science and Technology, 5.Kanazawa University, 6.Okayama University, 7.Univ. Pavia)

Keywords:IODP Exp. 360, Atlantis Bank, SloMo, Moho, D/V Chikyu

IODP Expedition 360, Phase I of the Nature of the Lower Crust and Moho at Slower Spreading Ridges (SloMo) project of a Multi-Leg Drilling Project, was carried out from 1 Dec., 2015 to 31 Jan, 2016, at Atlantis Bank, an oceanic core complex, along the eastern wall of the Atlantis II Transform of the Southwest Indian Ridge. We conducted all drilling operations at a single site in a single Hole U1473A and drilled 789.7 m though gabbros. This is the deepest single-leg hard-rock drilling hole in ocean crust. Expedition 360 Hole U1473 is located at 2.2 km Northeast of 1.5 km deep Hole 735B and at 1.4 km north of 158 m deep Hole 1105A. This provides us, for the first time, a unique opportunity to explore three dimensional lower crustal characteristics beneath the slow-spreading ridges. Phase II of the SloMo has proposed to drill 6 km through MOHO by the CHIKYU. In the meeting, we will introduce preliminary results of IODP Expedition 360 and the future perspective leading to Phase II of the SloMo, a mantle drilling into ultraslow-spreading ridges.