Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1 957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna tional publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 36 (thesis year 1991) a total of 11,024 thesis titles from 23 Canadian and 161 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work. While Volume 36 reports theses submitted in 1991, on occasion, certain univer sities do report theses submitted in previous years but not reported at the time.

This volume emphasizes the interaction of the Cordilleran thrust belt and Rocky Mountain foreland in studies of regional structural geology, geophysics, and sedimentology from west-central Montana to Arizona. The volume outlines how the nature of the Rocky mountain foreland and its deformation affect the geometry of the Cordilleran thrust belt. Many of the structural and geophysical studies reported in this volume also address the question of which structures - forland or thrust belt - developed first in a specific region and how early formed structures influenced later ones. Several chapters address the nature and style of foreland development.