Figure F57. Geometry of the shallow-dipping vein network crosscutting the dolerite in Hole 1109D. A. Overlapping tip zone between millimeter-thick greigite-filled veins in Section 180-1109D-47R-1 (777.6 mbsf). B. Cristobalite-filled extensional shear zone in Section 180-1109D-50R-3 (794.9 mbsf). The folded shape of the individual veins results from an advanced stage of horizontal shearing.