STRUCTURAL AND LITHOLOGIC INFLUENCES ON KARST SYSTEMS IN THE TONY GROVE AREA, NORTHERN UTAH

This research examines caves in the Tony Grove area of the Bear River Range in northern Utah with the goal of determining influences on cave morphology. For example, are they influenced by the syncline in the area, the lithology of the units, or both? Using a Brunton compass, a clinometer, and a laser range finder the necessary data was collected. The Cave passages were surveyed with the compass and clinometer, while the strike and dip of the fractures were taken with the Brunton. Using the data collected, the computer software ArcGIS, Oriana, and Compass were utilized to analyze the data. With over eighty-five caves in the area, seven main caves were chosen to survey. With five complete surveys and two partially complete, the caves have yielded 140 joints and over 450 meters of passage. Data from Polygamy Cave indicates that the majority of the passages are influenced by something other than the fracture orientations, possibly the lithology. Oriana shows that Polje Cave and BRG Cave passages are strongly influenced by fractures. Compass maps and ArcGIS indicate Main Drain Cave being influenced by the local fracture sets, although more data collecting is required for a determination. Other caves such as Double Sink, Thundershower, and Snowcone are currently in the process of data analysis. Maps in ArcGIS show the predominant formation of the caves in a southwesterly direction, the direction of the syncline axis and its plunge. A stratigraphic column is currently being constructed, with approximately 610 meters of Fish Haven Dolomite and Laketown Dolomite occurring in the area. Twelve samples have been taken to thin section to take a closer look at the composition of the rock. Eleven thin sections indicate dolomite, while one sample indicated recrystallized­ marine fossils. This stratigraphic section and the samples will allow a closer look into the lithology of the area and in the caves. Initial results indicate that some of the caves are influenced by the fractures created by folding while others are influenced by the lithology. Future work can incorporate cave hydrology into the structure and stratigraphy of the area to gain a better perspective on how water flows through the subsurface at Tony Grove and its surrounding areas.