EFFECTS OF SERPENTINIZATION ON THE LITHOSPHERIC STRENGTH AND THE STYLE OF NORMAL FAULTING AT SLOW-SPREADING RIDGES

Rock deformation experiments indicate that serpentinization can strong ly influence the strength and tectonics of the oceanic lithosphere. St rength versus depth profiles, calculated for conditions appropriate fo r slow-spreading ridges, indicate that the presence of serpentinite ca n reduce the integrated strength of the lithosphere by up to 30%. Resu lts from flexural fault models indicate that if serpentinization is is olated to fault zones, strain localization should be enhanced, providi ng an explanation for the variations in the style of normal faulting a long slow-spreading ridge segments. At segment centers, where serpenti nites are scarce, deformation is accommodated on closely spaced faults with small throws. At the segment ends, where serpentinites are most abundant, faults are widely spaced and have large throws. (C) 1997 Els evier Science B.V.