The crustal structure of the kane fracture zone from seismic refraction studies

摘要: A detailed seismic refraction experiment was carried out across the Kane Fracture Zone near 24°N, 44°W using explosive and air gun sound sources eight ocean bottom hydrophone receivers. The shooting lines receivers formed a ‘T’ configuration fracture zone, with two located about 50 km apart in zone trough remaining six positioned 25–30 on either side of zone. crustal thicknesses velocities observed at north south fall within range those typically for normal oceanic crust. There is no convincing evidence significantly different or upper mantle despite 10-m.y. age difference. Anomalously thin crust present beneath total only 2–3 km, half thickness This also characterized seismically by low compressional wave (∼4.0 km/s) shallow depths absence layer 3 refractor. anomalous extends over width least 10 km. Dense, high-velocity type material may exist adjacent ridge. Results from other geological geophysical studies zones suggest that this structure typical many Atlantic zones. We propose anomalously found these primary feature caused accretion thinner volcanic plutonic crust, which probably restricted to wider than transform fault valley (∼10 km) most cases, inferred consist few hundred meters extrusive basalts dikes overlying 2 gabbro metagabbro, possibly interbedded ultramafics. section be extensively fractured brecciated levels faulting active domain. relatively narrow can explain number characteristics including depth exposure deep rocks walls