Bryan Tikalsky Department of Geography Master of Science Mountain water resources are essential to those living along the Salt Lake City urban corridor. Water resource planners base their policy on twentieth century climate conditions and streamflow records. Often these records only account for a small amount of the natural variability in streamflow and climate. By utilizing dendrochronology this study seeks to better understand variability of streamflow in the Jordan River Drainage Basin over the last 828 years. A GIS model was used to identify potential sampling sites where tree growth would be sensitive to climate and factors affecting stream run-off. Over eighty samples from ancient limber pine (Pinus flexilis) and Douglas-fir (Pseudotsuga menziesii) were obtained to perform the reconstruction. Results indicate significant correlation between tree growth and streamflow. A multiple linear regression model created with tree-ring width as the predictor of October - March American Fork River streamflow explained 51.7% of streamflow variance. Analysis of the reconstruction indicates that present records do not adequately represent potential streamflow variability, and several droughts of greater severity and length occurred before the instrumental period.

Populations of Delphinium occidentale (Ranunculaceae)were monitored over two summers for the presence and dispersion of various life stages of several host specific phytophagous insects. Observations were made at several sites in the Wasatch National Forest east of Logan, Utah. Two species of larkspur aphid (Aphis rociadae and Kakimia wahinkae) were encountered. Although dispersal of alate individuals resulted in widespread infestation of the host plant population, aphids occurred initially on the same one or few plants at each site both springs. Little coexistence of the two species of aphid on the same plant was observed, perhaps because they partitioned the host plant resource according to light intensity under the incomplete aspen canopy. Several species of lepidopteran larvae, of uncertain host specificity, were observed. Two species (Autographa californica and pyrrhia expremins: Noctuidae) are known from cultivated host plants. Eggs of an unidentified geometrid (Lepidoptera) were located on the host plants in large numbers and their dispersion was analysed. The eggs were distributed nonrandomly over the host plant population, but attempts to further characterize the pattern were fruitless. Parasitism of the eggs by an unidentified hymenopteran was observed. Mortality of all larvae was high. Successful migration of larvae was not observed. Mature larvae were not sufficiently abundant to permit statistical study of pattern. Mature fruits were examined at the end of the growing season for larkspur maggots (Hylemya laxifrons). Maggots were found in 85 percent of the inflorescences sampled. Pteromalids (Hymenoptera) were also found in an apparently parasitic relationship with the maggots in the fruits. Maggots were not found in the surviving fruits of inflorescences infested with either species of aphid. Suggestions are given for future work.

The downstructure of viewing geologic maps, balanced and cross sections, and hanging-wall-sequence diagrams are applied to produce the first comprehensive synthesis of the structure below the willard thrust sheet. Development of the duplex beneath the Willard thrust may be explained with a "piggyback" thrust model where younger thrust slices form below and fold an older, overlying thrust sheet. Progressive failure of the footwall ramp of the Willard thrust sheet extended the sole thrust eastward and produced a duplex consisting of thrust slices (horses) which adhered to the overriding thrust sheet where it ramped from a lower sole thrust to an upper decollement horizon. The resulting structural culmination produced a distinct antiform in the Willard thrust sheet. The duplex is here named the Ogden duplex. Frontal folds (formed at ramps perpendicular to transport) and lateral folds (formed at ramps parallel to transport) mark the margin of Individual horses within the duplex. Folded thrusts, thrust-splay relationships, and lateral overlap of horses help determine the sequence of thrusting. The involvement of cratonic foreland basement rocks (Farmington Canyon Complex) in thrust slices within the Ogden duplex is similar to the Moine thrust belt in northern Scotland and pinpoints this area within zone III of Boyer and Elliott's (1982) model of a thrust system dominated by a major thrust sheet. The basement rocks form the core of several horses which moved a minimum of 9.6 km. Total shortening within the Ogden duplex is estimated at 8 to 12 km. The sequence of thrusting is proposed from higher to lower: the willard thrust fault moved first, then the Ogden thrust fault and, finally, the Taylor and Weber thrust system (here named). Striking similarities between the Ogden thrust fault, the Weber-Taylor thrust system, and the Durst thrust fault geometries suggest that they are all part of the same system.

This paper deals with the seasonal distribution, relative abundance, and location of the different species of birds which visit or live on the Brigham Young University campus from late summer to early spring, with a brief account of their activities. The upper campus, where this investigation was carried on, covers an area of 201 acres and is situated on a bench at the foot of the Wasatch Mountains. The study was continued from July 13, 1955 to April 15, 1956. A total of 173 hours was devoted to census work and to studying the general ecology of the area. Four to five censuses were taken in each month of study. In order to measure the relative abundance, the total number of each species seen per hour was calculated. The location of each species found during this study was plotted on an outline map of the campus. Fifty-five different kinds of birds were seen on the campus during this study. The Western Robin, English Sparrow, California Quail, Song Sparrow and Red-shafted Flicker were seen constantly in every month of study. The Red Crossbill and Sage Hen, two most uncommon species in this area, were observed. The maximum number of species was found in July, and the minimum in December. Nests of House Finch, Western Robin, Blackheaded Grosbeak, Song Sparrow, Long-tailed Chat, California Quail, Mourning Dove, Pine Siskin, Starling and English Sparrow were found in this study area. New arrivals were noticed in every month. The majority of these species, as well as individuals, were located in the tree area bordering the canal. From this study it was found that the Brigham Young University campus provides a very suitable habitat for many species of birds. Ample cover, food, and water are available, and firearms are prohibited. The movement of students and other traffic about the campus does not seem to hamper the birds in their normal activities to any appreciable degree.