W.J. McGee 1888 <p>In view of the active discussion of the problems of earth-movement and mountain-growth now current, certain fundamental definitions, growing out of the discrimination of processes commonly confounded but really distinct, seem to be timely.</p><p>The various processes with which the geologist has to deal fall naturally into two principal and antagonistic categories and five subordinate and supplemental categories; and each category, great and small, comprises two antagonistic classes of movements or agencies.</p> application/pdf 10.1017/S0016756800182755 en Cambridge University Press IV.-Some Definitions in Dynamical Geology article