Robert J. Twiss is an American geologist emeritus of University of California, Davis. He made his Ph.D. 1971 at Princeton University.Twiss’ webpage at UC Davis (from Internet Archive)
First in his career he researched viscosity of earth mantle. Nowadays he interests for the mechanisms and mechanics of rock deformation and the interpretation of connected structures.Robert J. Twiss, Randall Marrett (2010). "Determining brittle extension and shear strain using fault-length and displacement systematics: Part I: Theory"
Together with geologist Eldridge M. Moores he has co-authored two famous textbooks: Tectonics and Structural Geology.
Bibliography Eldridge M. Moores, Robert J. Twiss (1995) Tectonics (W. H. Freeman)
References