We've discussed this sort of thing for southern California offshore and near onshore faults...I guess the credit should go to Mark Legg. There are low-angle faults that were normal faults 20-5 million years ago....some of these are pretty flat....and blocks may be sliding around above them, and link the shallow sub-vertical strike-slip faults.
A lot of the strike-slip faults are not vertical: the paper I am working on (and various reports of ours that are already out there show that the offshore Santa Monica-Dume fault dips 40-45 deg north, and it is a left-lateral fault in its eastern offshore part.
Chris