Niichi Nishiwaki

Automatic analysis of geologic structure from dip-strike data

Abstract A new technique for structural analysis is described. From dip-strike data, a dip—strike distribution map, structure contour map, and block diagram are automatically prepared on an X-Y plotter by using four computer programs. Three test examples of theoretical data are treated as well as an actual example. The Izumi Group (Upper Cretaceous) is revealed to have a more complicated structure than previously recognized.

Discrimination of areal groups of japanese quaternary volcanic rocks using major-element chemical analytical data

Abstract Data analysis was applied by means of a temporary data processing system connecting several general purpose programs to a small data base which is composed of major-element chemical analyses of Japanese Quaternary volcanic rocks. Trend-surface analysis of each chemical component and discriminant analysis of 5 areal groups of volcanoes were performed, and their results were displayed geographically. The system used here is convenient because no new program was required to be developed.