Robert J. Twiss

{{short description|American geologist}}

Robert J. Twiss is an American geologist emeritus of University of California, Davis. He made his Ph.D. 1971 at Princeton University.[https://web.archive.org/web/20120426120637/https://www.geology.ucdavis.edu/faculty/twiss.html Twiss’ webpage at UC Davis] (from Internet Archive)

First in his career he researched viscosity of earth mantle.

{{cite journal

| author = Robert J. Twiss

| authorlink =

|date=November 1976

| title = Structural superplastic creep and linear viscosity in the earth's mantle

| journal = Earth and Planetary Science Letters

| volume = 33

| issue = 1

| pages = 86–100

| doi = 10.1016/0012-821x(76)90160-6

| bibcode =1976E&PSL..33...86T

}}

Nowadays he interests for the mechanisms and mechanics of rock deformation and the interpretation of connected structures.

{{cite journal

| author = Robert J. Twiss, Michael J. Gefell

| authorlink =

| date = January 1990

| title = Curved slickenfibers: a new brittle shear sense indicator with application to a sheared serpentinite

| journal = Journal of Structural Geology

| volume = 12

| issue = 4

| pages = 471–481

| doi = 10.1016/0191-8141(90)90035-w

| bibcode =1990JSG....12..471T

}}

Robert J. Twiss, Randall Marrett (2010). "Determining brittle extension and shear strain using fault-length and displacement systematics: Part I: Theory" {{doi|10.1016/j.jsg.2010.04.007}}

Together with geologist Eldridge M. Moores he has co-authored two famous{{Citation needed|date=July 2015}} textbooks: Tectonics and Structural Geology.