Introduction: One of several models that has been proposed to explain the present chemical and minera-logical nature of the Martian surface is referred to as the " acid-fog " model. This model involves the recent (up to 1Ga), slow and continuous interaction of acidic volatiles, presumably of volcanic origin, with the exposed Martian basaltic crust [1, 2]. As a result of this interaction, minera...

Smith, D. R. and Leeman, W. P., 1993. The origin of Mount St. Helens andesites. J. Volcanol. Geotherm. Res., 55: 271-303. Mount St. Helens volcano has intermittently produced mainly dacitic products but occasionally erupted a more diverse suite of lavas including basalts and andesites. Petrogenetic relations between these magmas provide insight into the dynamics of the subjacent magma system. M...

Explosive volcanic eruption requires that magma fragments into discrete parcels. Silicic magma can fragment through brittle failure or other processes that depend on the viscoelasticity of the melt. Owing to the low viscosity of basaltic magmas, however, the fragmentation mechanism must be different and will be governed by fluid mechanics alone. We perform a series of decompression experiments ...

12 Observations in the USA, Iceland, and Tenerife, Canary Islands, reveal how processes occurring 13 during basaltic eruptions can result in complex physical and stratigraphic relationships between lava 14 and proximal tephra fall deposits around vents. Observations illustrate how basaltic lavas can 15 disrupt, dissect (spatially and temporally) and alter sheet-form fall deposits. Complexity ar...

Introduction: One of the major and outstanding problem in Venus geology is: Does Venus possess a non-basaltic crustal component which may be an analog to the continental crust of Earth [e.g. 1]? Detailed photogeologic analysis of plains units that make up the majority of the surface of Venus strongly suggests that the plains were formed by eruptions of low-viscosity lavas [2-4]. Such a morpholo...

Introduction: The lunar mare basalts potentially provide a unique sample suite for understanding the nature of basalts on the martian surface. Our current knowledge of the mineralogical and chemical composition of the basaltic material on Mars comes from studies of the basaltic martian meteorites and from orbital and surface remote sensing observations. Petrographic observations of basaltic mar...

Owing to advances in microanalytical techniques over the last 15 years, there is a growing database on the volatile contents of subduction-related magmas as recorded in melt (glass) inclusions trapped in phenocrysts in volcanic rocks. Basaltic magmas from subduction zones show a wide range of water contents, ranging from as high as 6–8 to b0.5 wt.% H2O. Variations are related in some places to ...

Geochemical models of secondary mineral precipitation on Mars generally assume semiopen systems (open to the atmosphere but closed at the water-sediment interface) and equilibrium conditions. However, in natural multicomponent systems, the reactive surface area of primary minerals controls the dissolution rate and affects the precipitation sequences of secondary phases, and simultaneously, the ...

The search for once-habitable locations on Mars is increasingly focused on environments dominated by fluvial and lacustrine processes, such as those investigated by the Mars Science Laboratory Curiosity rover. The availability of liquid water coupled with the potential longevity of such systems renders these localities prime targets for the future exploration of Martian biosignatures. Fluvial-l...

We present a quantitative assessment of the thermal and dynamic response of an amphibolitic lower crust to the intrusion of basaltic dike swarms in an arc setting. We consider the effect of variable intrusion geometry, depth of intrusion, and basalt flux on the production, persistence, and interaction of basaltic and crustal melt in a stochastic computational framework. Distinct melting and mix...