ABSTRACT Large-scale landslide deposits (covering >1 km 2 ) are prevalent throughout the Basin and Range province. However, their presence and importance in the evolution of the Basin and Range remain poorly recognized. On this field trip, we will visit four landslide deposits along the eastern flank of the Spring Mountains on the western margin of Las Vegas Valley. The first half of the day will be spent looking at vertical and lateral textures within the Blue Diamond landslide deposit, which mostly caps hills and ridges between the southern ends of the Wilson Cliffs and Blue Diamond Hill. We interpret this deposit as having a two-phase emplacement, with an initial rock avalanche emplacement onto Blue Diamond Hill, followed by failure as a rock compound landslide along weak gypsum layers in the Kaibab Formation. During the second half of the day, we will visit a smaller rock avalanche deposit (La Madre), a large rock compound slide that resulted from failure of the northern flank of Blue Diamond Hill (Red Rock Wash), and a large block of Paleozoic rock that likely was emplaced as either a rock compound slide or a rock planar slide (Lone Mountain).

Abstract The Kaibab Plateau and Grand Canyon National Park in the USA contain both shallow and deep karst systems, which interact in ways that are not well known, although recent studies have allowed better interpretations of this unique system. Detailed characterization of sinkholes and their distribution on the surface using geographical information system and LiDAR data can be used to relate the infiltration points to the overall hydrogeological system. Flow paths through the deep regional geological structure were delineated using non-toxic fluorescent dyes. The flow characteristics of the coupled aquifer system were evaluated using hydrograph recession curve analysis via discharge data from Roaring Springs, the sole source of the water supply for the Grand Canyon National Park. The interactions between these coupled surface and deep karst systems are complex and challenging to understand. Although the surface karst behaves in much the same way as karst in other similar regions, the deep karst has a base flow recession coefficient an order of magnitude lower than many other karst aquifers throughout the world. Dye trace analysis reveals rapid, conduit-dominated flow that demonstrates fracture connectivity along faults between the surface and deep karst. An understanding of this coupled karst system will better inform aquifer management and research in other complex karst systems.

Abstract This guide provides background information and an itinerary for a one-day field trip leaving from Price, Utah, and ending near Moab, Utah. The field-trip route identified leads through central and southeastern Utah and provides opportunities to examine features such as the Laramide tectonics manifested in the San Rafael Swell, sedimentary rocks of the Cretaceous Western Interior Seaway and the sandstone arches, extensional faulting, and salt tectonics in and around Arches National Park.