Earthquake Source Mechanics

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 37.

A number of rocks have achieved a kind of fame in geophysical circles because of their frequent use in experimental studies. The names Carrera marble, which has attained a far larger fame in its use for Italian sculpture and facades, Yule marble, and Solenhofen limestone come immediately to mind as experimentalists' rocks. None, however, can match the longevity and shear body of study devoted to them as that of the granite from Westerly, Rhode Island. It is because of the great attention that has been played upon this rock and because of the considerable difficulty one encounters in obtaining a sample of it (it has not been commercially quarried in over 25 years), that Westerly granite has achieved a sort of cult status among experimental geophysicists. It is ironic that many who use the well-worn quip "geophysicists think that the crust is made of Westerly granite" are probably unaware that Westerly granite was once designated by the U.S. Geological Survey and the Carnegie Institution as 'G-1', the type rock of the continental crust [Fairbairn et al., 1951].