The Journal of Geology, Vol. 46, No. 3, Part 2 (Apr. - May, 1938), pp. 505-520 (16 pages) A modified variation diagram for plotting groups of chemical analyses of ...

WITH the collaboration of Dr. A. K. Wells, this well-known text-book has been revised and extended until now it is virtually a new book. Among the new features are chapters dealing with the ...

Vast accumulations of igneous rock, termed large igneous provinces, are found in various regions of the globe. These masses of rock were erupted very rapidly — geologically speaking — usually over a ...