Upper mantle and its effects on earth's crust

Some 40 papers among a larger number presented at the First All-Union Conference analyzing the results of the I. G. Y., held in Moscow from January 24 to February 5, 1963 are reviewed in this article. A summary points out the cumulative weight of evidence favoring a close connection between processes in the mantle and crust and arguing against continental drift. The significance of continental-type composition of Icelandic lavas, which contrast with the magmas known in other parts of the Atlantic Ocean, is expressed as an indication that suboceanic mantle can be converted from continental type to oceanic type in the time interval which has elapsed since the beginning of the Cretaceous.—B. N. Cooper