The straightforward but unexpected relationship presented here relates crustal thickness to magma type in the Izu-Ogasawara (Bonin) and Aleutian oceanic arcs. Volcanoes along the southern segment of the Izu-Ogasawara arc and the western Aleutian arc (west of Adak) are underlain by thin crust (10-20 km). In contrast those along the northern segment of the Izu-Ogasawara arc and eastern Aleutian a...

Volcán San Pedro in the Andean Southern Volcanic Zone (SVZ) Consequently, the role of young, unradiogenic hydrous gabbro in Chile, comprises Holocene basaltic to dacitic lavas with trace generating dacite and contaminating basalt may be underappreciated element and strontium isotope ratios more variable than those of in the SVZ. most Pleistocene lavas of the underlying Tatara–San Pedro complex....

Introduction: Basaltic pyroclastic rocks are uncommon on Earth because most mafic magmas are too volatile-poor to drive explosive eruptions [3-4]. However, basaltic pyroclastic deposits maybe much more common on Mars than on Earth [4-7] because Mars’ lower gravity and thinner atmosphere permit explosive eruptions from magmas with lower volatile contents. Though rare, basaltic pyroclastic rock o...

The geochemical composition of surface soils and potential bedrocks in Davarzan area has been investigated to determine soil origin and evaluate environmental aspects. Davarzan plain is composed of soils and deposits derived by weathering and transportation of different bedrocks from northern mountains. The bedrocks consist of Eocene (andesitic to basaltic lavas and volcano-sedimentary rocks co...

Introduction: Water liquid has been considered to be main fluid in cold Mars, though major sources of liquid water are not clearly found on Martian surfaces. Recently author (Y.M.) found carbon-bearing grains on plagioclase composition in druses of terrestrial volcanic basalts in Shimonoseki, Yamaguchi, Japan [1], where many scientists have been reported as normal “plagioclases” formed at hydro...

The Muria-Peninsula is a Quaternary volcano located in the northern Sunda arc. Its activity was controlled under high potassic and very magma series resulting leucite-rich trachyte pyroxene-rich basaltic-andesite. It strato-type that composed of lava, breccia, tuff layers, some dikes have volcanic craters maars varying age composition. study area covering volcanoes Muria, Genuk, Patiayam. This ...

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...