XLbc S^ournal of 0eolog^ 



Vol. XXII CONTENTS FOR JULY-AUGUST J9J4 No. 5 



THE STRENGTH OF THE EARTH'S CRUST. V. THE DEPTH OF MASSES PRODUCING GRAVITY 



ANOMALIES AND DEFLECTION RESIDUALS --------- Joseph Barrell 441 



CERTAIN TYPES OF STREAM VALLEYS AND THEIR MEANING - John Lyon Rich 469 



STREAM PIRACY AND NATURAL BRIDGES IN THE LOESS OF SOUTHEAST MISSOURI - C. L. Dake 498 



CRYSTALLOBLASTIC ORDER AND MINERAL DEVELOPMENT IN METAMORPHISM 



Frederic H. Lahee 500 



DIASTROPHISM AND THE FORMATIVE PROCESSES. VIII. THE QUANTITATIVE ELEMENT IN 



CIRCUM-CONTINENTAL GROWTH - T. C. Chamberlin 516 



PETROLOGICAL ABSTRACTS AND REVIEWS 529 



RECENT PUBLICATIONS - 534 



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