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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 1957, 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 thougtit 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 31 (thesis year 1986) a total of 11 ,480 theses titles trom 24 Canadian and 182 United States universities. We are sure that this broader base tor these titles reported will greatly enhance the value ot this important annual reterence work. While Volume 31 reports theses submitted in 1986, on occasion, certain univer sities do re port theses submitted in previousyears but not reported at the time.
The Strawn-Canyon boundary is traced from the Colorado River valley of Texas to the Brazos River valley. Equivalent beds of the Capps limestone, uppermost Strawn unit of the Colorado River valley, are mapped in the Pennsylvanian inlier in Comanche County and in Eastland and Palo Pinto counties. In Eastland County the Strawn-Canyon boundary is placed at the top of the "boulder bed," which lies 15 feet above the limestone equivalent of the Capps limestone. The equivalent of the "boulder bed" in Palo Pinto County is the lenticular Village Bend limestone, but the top of the Strawn series is drawn at the base of the overlying Lake Pinto sandstone. The best criterion for establishment of the Strawn-Canyon boundary is paleontologic change. The series of the Pennsylvanian are established primarily on the basis of fusulinid zones. Strawn series is characterized by the genus Fusulina; Canyon series, by Triticites. The brachiopod Mesolobus and bryozoan Prismopora, occurring in pre-Canyon beds, serve as supplementary evidence in establishing the boundary. Upper Strawn and lower Canyon stratigraphic units are typically irregular and heterogeneous. Exceptionally, the Capps limestone equivalent of Eastland and Comanche counties and the Dog Bend limestone of Palo Pinto and Parker counties are rather uniform in lithology and thickness. Upper Strawn and lower Canyon sandstones are orthoquartzites, of the "washed-graywacke" type. The sandstones are characterized by a fair percentage of chert and by simple heavy mineral suites. The limestones are composed largely of detrital material. The Capps limestone, in part, and its equivalents are calcarenites; the Village Bend and Dog Bend limestones, calcilutites. Partial chemical analyses and differential thermal analyses of the carbonate rocks reveal that the predominant carbonate mineral is calcite. As suggested by the orthoquartzite and total thickness of Pennsylvanian beds, the exogeosyncline of north-central Texas during the Pennsylvanian period subsided at a rather slow rate. The irregularity of upper Strawn and lower Canyon strata is typical of sediments deposited near the strand line. The sandstones and shales were deposited in both nonmarine and marine environments. Cycles or rhythms in sedimentation during late Strawn and early Canyon time are somewhat obscured by the influx of sediments from the nearby source, which lay to the east and southeast.