Movements of the Earth's Crust

Abstract

PROF. HANS STILLE of G6ttingen has issued, under the title of “Die Schrumpfung der Erde” (Berlin: Borntraeger; price Is. 8d.), a “Festrede” given to his university, in which he aptly reviews old and new theories as to the effect of the˜ earth's contraction on the features of the surface. He holds that the conception of a general contraction towards the interior is well founded; but there are many ways in which it may become manifest by wrinklings of the outer crust. He finds that what G. K. Gilbert styled “epeirogenic” (now written “epirogenetic”) movements, the sinking or uplifting of the crust over wide areas, are more in need of explanation than the folding of mountain-ranges, which has been differentiated as orogenetic.” The rhythmic pulsation, however, that causes mountain-building to occur simultaneously and even catastrophically over the whole earth presents an unsolved problem. Prof. J. Joly has suggested in a recent lecture (NATURE, May 5, p. 603) that the heat generated by radioactive minerals accumulates at intervals of some millions of years and so causes a catastrophe. Cooling of the uplifted layers by their being brought into proximity with the overlying oceans starts a new era of quiescence.