Presentation on theme: "CHARACTERIZING BOULDER DEPOSITION TO ASSESS ROCK-FALL HAZARD IN UPPER PINES CAMPGROUND, YOSEMITE NATIONAL PARK, CALIFORNIA CORDES, Shaun E., STOCK, Greg."— Presentation transcript:
CHARACTERIZING BOULDER DEPOSITION TO ASSESS ROCK-FALL HAZARD IN UPPER PINES CAMPGROUND, YOSEMITE NATIONAL PARK, CALIFORNIA CORDES, Shaun E., STOCK, Greg M., SCHWAB, Brandon E., and BURKE, Raymond M. Humboldt State University Department of Geology 1 Harpst St, Arcata, CA 95521 email@example.com
Purpose To differentiate between boulders of potential glacial and rock fall origin in order to assess geologic hazards within the Upper Pines campground (UPC) Boulder in Curry Village from 2008 rock fallBoulder in Upper Pines Campground
Hypotheses Boulders in Upper Pines Campground could have been transported by two primary processes: (1)glacial ( >15 ka – Last Glacial Maximum) (2)rock-fall (<15 ka) Field and GPS mapping XRF analysis Cosmogenic 10Be exposure ages Methods
UP-Cosmo-1 Age: 10,917 +/- 1043 XRF: falls within Gray et al. Khd data UP-Cosmo-2 Age: 9,607 +/- 954 XRF: intermediate between Khd/Kgp Contact ~460m above UPC
Half Dome granodiorite (Khd) and Glacier Point granodiorite (Kgp) contact
Provisional Conclusion Large boulders in the SW corner of the Upper Pines Campground are post-glacial and ~10 ka in age. XRF analysis suggests that UP-Cosmo-2 was near the Khd/Kgp contact ~460m above Upper Pines on Glacier Point Rock fall appears to be the more likely origin for large boulders in the SW corner of the campground.