Show Earth Movement l Professor Joseph Le Coute Come recently read a paper before the Geological Society Society So So- of America from which we ve learn learo that there uro aro two primary and permanent permanent perma perma- nent kinds of movements of the earths earth's crust namely crust namely those which cause continental continental continental con con- surfaces s and oceanic oceania basins and those which by interior contraction determine mountains of folded ture These two are determined the theone theone theone one by radial contraction the theother theother other er by unequal concentric contraction that is contraction of the interior mme more than the exterior There are also two secondary kinds kinds' of movement which modify the effects of the other two and confuse oar our understanding of them These are first oscillatory move move- affecting large arc areas areas' s and fatio movements or read read- d ji it by erosion and Jand sedimentation tion In the minds of some of some writers oscillatory oscillatory os os- movements have masked and obscured the effects of continent and ocean basin making and has bas concealed the effects and prevented the proper inter interpretation r tati n of all the others It is believed that to make secure progress progress ress rest we must keep ke p these several kinds of movements distinct in our minds San Francisco Francis Chron Chronicle cle |