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Evolution Of The Southwest Indian Ridge From 55 Degrees 45 ' E To 62 Degrees E: Changes In Plate-Boundary Geometry Since 26 Ma, A. G. Baines, Michael Cheadle, H.J.B. Dick, A. H. Scheirer, Barbara John, N. J. Kusznir, T. Matsumoto
Evolution Of The Southwest Indian Ridge From 55 Degrees 45 ' E To 62 Degrees E: Changes In Plate-Boundary Geometry Since 26 Ma, A. G. Baines, Michael Cheadle, H.J.B. Dick, A. H. Scheirer, Barbara John, N. J. Kusznir, T. Matsumoto
Michael Cheadle
[1] From 55 degrees 45'E to 58 degrees 45'E and from 60 degrees 30'E to 62 degrees 00'E, the ultraslow-spreading Southwest Indian Ridge (SWIR) consists of magmatic spreading segments separated by oblique amagmatic spreading segments, transform faults, and nontransform discontinuities. Off-axis magnetic and multibeam bathymetric data permit investigation of the evolution of this part of the SWIR. Individual magmatic segments show varying magnitudes and directions of asymmetric spreading, which requires that the shape of the plate boundary has changed significantly over time. In particular, since 26 Ma the Atlantis II transform fault grew by 90 km to reach 199 km, …
Evolution Of The Southwest Indian Ridge From 55 Degrees 45 ' E To 62 Degrees E: Changes In Plate-Boundary Geometry Since 26 Ma, A. G. Baines, Michael Cheadle, H.J.B. Dick, A. H. Scheirer, Barbara John, N. J. Kusznir, T. Matsumoto
Evolution Of The Southwest Indian Ridge From 55 Degrees 45 ' E To 62 Degrees E: Changes In Plate-Boundary Geometry Since 26 Ma, A. G. Baines, Michael Cheadle, H.J.B. Dick, A. H. Scheirer, Barbara John, N. J. Kusznir, T. Matsumoto
Barbara John
[1] From 55 degrees 45'E to 58 degrees 45'E and from 60 degrees 30'E to 62 degrees 00'E, the ultraslow-spreading Southwest Indian Ridge (SWIR) consists of magmatic spreading segments separated by oblique amagmatic spreading segments, transform faults, and nontransform discontinuities. Off-axis magnetic and multibeam bathymetric data permit investigation of the evolution of this part of the SWIR. Individual magmatic segments show varying magnitudes and directions of asymmetric spreading, which requires that the shape of the plate boundary has changed significantly over time. In particular, since 26 Ma the Atlantis II transform fault grew by 90 km to reach 199 km, …
Nonvolcanic Seafloor Spreading And Corner-Flow Rotation Accommodated By Extensional Faulting At 15 Degrees N On The Mid-Atlantic Ridge: A Structural Synthesis Of Odp Leg 209, T. Schroeder, H.J.B. Dick, U. Faul, J. F. Casey, P. B. Kelemen
Nonvolcanic Seafloor Spreading And Corner-Flow Rotation Accommodated By Extensional Faulting At 15 Degrees N On The Mid-Atlantic Ridge: A Structural Synthesis Of Odp Leg 209, T. Schroeder, H.J.B. Dick, U. Faul, J. F. Casey, P. B. Kelemen
Michael Cheadle
[1] Drilling during ODP Leg 209, dredging, and submersible dives have delineated an anomalous stretch of the Mid-Atlantic Ridge north and south of the 15 degrees 20'N Fracture Zone. The seafloor here consists dominantly of mantle peridotite with gabbroic intrusions that in places is covered by a thin, discontinuous extrusive volcanic layer. Thick lithosphere ( 10 - 20 km) in this region inhibits magma from reaching shallow levels beneath the ridge axis, thereby causing plate accretion to be accommodated by extensional faulting rather than magmatism. The bathymetry and complex fault relations in the drill-core suggest that mantle denudation and spreading …