A conceptual site model (CSM) has been developed for the Newark Bay Study Area (NBSA) as part of the Remedial Investigation/Feasibility Study (RI/FS) for this New Jersey site. The CSM is an evolving document that describes the influence of physical, chemical and biological processes on contaminant fate and transport. The CSM is initiated at the start of a project, updated during site activities, and used to inform sampling and remediation planning. This paper describes the hydrodynamic and sediment transport components of the CSM for the NBSA. Hydrodynamic processes are influenced by freshwater inflows, astronomical forcing through two tidal straits, meteorological conditions, and anthropogenic activities such as navigational dredging. Sediment dynamics are driven by hydrodynamics, waves, sediment loading from freshwater sources and the tidal straits, sediment size gradation, sediment bed properties, and particle-to-particle interactions. Cohesive sediment transport is governed by advection, dispersion, aggregation, settling, consolidation, and erosion. Noncohesive sediment transport is governed by advection, dispersion, settling, armoring, and transport in suspension and

Long-runout landslides are well-known and notorious geologic hazards in many mountainous parts of the world. Commonly encompassing enormous volumes of debris, these rapid mass movements place populations at risk through both direct impacts and indirect hazards, such as downstream flooding. Despite their evident risks, the mechanics of these large-scale landslides remain both enigmatic and controversial. In this work, we illuminate the inner workings of one exceptionally well-exposed and well-preserved long-runout landslide of late Pleistocene age located in Eureka Valley, east-central California, Death Valley National Park. The landslide originated in the detachment of more than 5 million m3 of Cambrian bedrock from a rugged northwest-facing outcrop in the northern Last Chance Range. Its relatively compact scale, well-preserved morphology, varied lithologic composition, and strategic dissection by erosional processes render it an exceptional laboratory for the study of the long-runout phenomenon in a dry environment. The landslide in Eureka Valley resembles, in miniature, morphologically similar “Blackhawk-like” landslides on Earth, Mars, and minor planet Ceres, including the well-known but much larger Blackhawk landslide of southern California. Like these other landslides, the landslide in Eureka Valley consists of a lobate, distally raised main lobe bounded by raised lateral levees. Like other terrestrial examples, it is principally composed of pervasively fractured, clast-supported breccia. Based on the geologic characteristics of the landslide and its inferred kinematics, a two-part emplacement mechanism is advanced: (1) a clast-breakage mechanism (cataclasis) active in the bedrock canyon areas and (2) sliding on a substrate of saturated sediments encountered and liquefied by the main lobe of the landslide as it exited the main source canyon. Mechanisms previously hypothesized to explain the high-speed runout and morphology of the landslide and its Blackhawk-like analogs are demonstrably inconsistent with the geology, geomorphology, and mineralogy of the subject deposit and its depositional environment.

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This paper describes the regional geology, dimensions, morphology, sedimentology, and age relations of the Holocene "Carlson landslide," a large moist landslide composed of basalt breccia located on the eastern margin of the Lost River Range, Idaho. These data are combined to deduce the factors that prompted the slope failure, the kinematics of initiation, travel, and stopping of the landslide, as well as its postemplacement degradation. The landslide is compared with other terrestrial mass movements on the basis of morphology, sedimentology, log(volume) versus fall height –runout length (H/L) relations and estimated Bingham plastic yield strength. Morphology and sedimentology distinguish dry landslides from moist and water-saturated deposits. However, moist and water-saturated landslides plot well within the log(volume) versus H/L envelope for dry terrestrial landslides and exhibit overlapping ranges of estimated Bingham plastic yield strength values with dry landslides, indicating that moist and water-saturated landslides must travel much like dry rock avalanches of similar volume. Thus the mechanism(s) responsible for causing anomalous runout in large dry landslides could operate in moist and water-saturated landslides as well. Morphological comparison of the Carlson landslide with lobate martian landslides suggests a role for water in the martian landslides. Key words: landslides, debris flows, long runout, morphology, water, Mars.

Ka Loko Dam, in Kauai, Hawaii, failed suddenly and catastrophically on March 14, 2006. The resulting breachwas marked by three topographic benches, the lowest of which exposed native volcanic deposits once resident in the dam foundation. These deposits were found to contain outcrops of a waxy, gel-like material that appeared to result from in situ weathering processes. This unusual material was found to be highly enriched in halloysite. Gravel-size pieces in the hydraulic fill of the embankment derived from these materials also exhibited significant in situ weathering and significant halloysite content. Engineers and geologists generally recognize that bedrock materials weather progressively into soil constituents over ‘geological time’, and that this process is accelerated in tropical environments. Still, the strength, stiffness and durability of bedrock, earth and embankment materials are not expected to vary significantly over the geologically short life of a dam. In the case of Ka Loko Dam, however, the volcaniclastic sediments that comprise the local bedrock experienced substantial in situ weathering over its geologically brief 115-year operational lifetime. Prolonged exposure to seepage of anoxic water weathered the sediments completely to saprolite, including weak, sensitive, fine, spherical halloysite.