Takeshi Matsumoto Corresponding Author Address:

• Main Authors: Maurice Tivey, Akira Takeuchi, Wmark Scientific Party, Wilfred Bryan, Hiromi Fujimoto, Toshiya Fujiwara, Toshio Furuta, Hideo Ishizuka, Peter Kelemen, Hajimu Kinoshita, Maurice A. Tivey
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Kane; Median Ridge; Mid-Atlantic Ridge; North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.507.2802; http://www.ldeo.columbia.edu/files/uploaded/file/1998 Tivey et al_ MGR.pdf

In 1994, a joint Japanese-American dive program utilizing the worlds deepest diving active research submersible (SHINKAI 6500) was carried out at the western ridge-transform intersection (RTI) of the Mid-Atlantic Ridge and Kane transform in the central North Atlantic Ocean. A total of 15 dives were completed along with surface-ship geophysical mapping of bathymetry, magnetic and gravity fields. Dives at the RTI traced the neovolcanic zone up to, and for a short distance (2.5 km) along, the Kane transform. At the RTI, the active trace of the transform is marked by a narrow valley (< 50 m wide) that separates the recent lavas of the neovolcanic zone from the south wall of the transform. The south wall of the transform at the western RTI consists of a diabase section near its base between 5000 and 4600 m depth overlain by basaltic lavas, with no evidence of gabbro or deeper crustal rocks. The south wall is undergoing normal faulting with considerable strike-slip component. The lavas of the neovolcanic zone at the RTI are highly magnetized (17 A/m) compared to the lavas of the south wall (4 A/m), consistent with their age difference. The trace of the active transform changes eastwards into a prominent median ridge, which is composed of heavily sedimented and highly serpentinized peridotites. Submersible observations made from SHINKAI find that the western RTI of the