0019-1035/$ see front matter 2010 Elsevier Inc. A doi:10.1016/j.icarus.2010.12.014 ⇑ Fax: +1 480 965 8102. E-mail address: [email protected] The surface of Mercury contains ancient volcanic features and signs of pyroclastic activity related to unknown magmatic volatiles. Here, the nature of possible magmatic volatiles (H, S, C, Cl, and N) is discussed in the contexts of formation and evolution of...

We report on detailed laboratory experiments designed to illustrate the frictional behavior of granular volcanic debris. The materials include pyroclastic flow debris from Soufrière Hills Volcano, Montserrat, and from Stromboli Volcano, Italy, and lahar deposits from Mount St. Helens. Experiments were conducted in a servo-controlled, double-direct shear apparatus under conditions of displacemen...

The development of particle-enriched regions (bed-load) at the base of particle-laden gravity currents has been widely observed, yet the controls and relative partitioning of material into the bed-load is poorly understood. We examine particle-laden gravity currents whose initial mixture (particle and fluid) density is greater than the ambient fluid, but whose interstitial fluid density is less...

Abstract Dark, windblown (eolian) sand on Mars has produced significant geologic effects throughout Martian history. Although local and regional sources have been identified, a primary origin, or genesis, for not demonstrated. This knowledge gap was recently heightened by the discovery of widespread motion, implying breakdown grains to sub-sand sizes. To address question we investigated source(...