Andean volcanism occurs within the Andean Volcanic Arc (AVA), which is the product of subduction of the Nazca Plate and Antarctica Plates beneath the South America Plate. The AVA is Earth’s longest but discontinuous continental-margin volcanic arc, which consists of four distinct segments: Northern Volcanic Zone, Central Volcanic Zone, Southern Volcanic Zone, and Austral Volcanic Zone. These se...

Lunar volcanic deposits are dominated by areally extensive mare units occurring in regionally low areas predominantly on the lunar near side. Data obtained from lunar orbit and earth-based observations have been used to extend the detailed characterizations derived from Apollo and Luna sample return missions to other parts of the moon. Mare volcanism occurred over a period of about 1.3 billion ...

Satellite altimetry is used to identify and characterize Pacific intraplate seamounts. The gravimetric amplitudes of seamounts appear to be related to the age difference between seafloor and seamounts; by inverting this relationship pseudo ages can be obtained for undated seamounts. These pseudo ages imply that excursions in seamount volcanism generally correlate with times of formation of larg...

Crowley et al. (Reports, 13 March 2015, p. 1237) propose that abyssal hill topography can be generated by variations in volcanism at mid-ocean ridges modulated by Milankovitch cycle-driven changes in sea level. Published values for abyssal hill characteristic widths versus spreading rate do not generally support this hypothesis. I argue that abyssal hills are primarily fault-generated rather th...

We have compiled the distribution of active faults and folds in the HimalayanTibetan orogen and its immediate surrounding regions into a web-based digital map. The main product of this study is a compilation of active structures that came from those documented in the literature and from our own interpretations based on satellite images and digital topographic data. Our digital tectonic map allo...

Earth is no stranger to volcanism. Since proto-Earth and crustal formation, volcanoes have provided pathways for degassing and cooling of our planet’s interior. Volcanism played an important role in the formation of the early atmosphere, oceans and continents, and was likely a necessary component for the development of life. Throughout our species brief history, innumerable volcanoes have erupt...

Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. [1] The Pacific Northwest (PNW) has a complex tectonic history and over the past $17 Ma has played host to several ...

1019 eology, November 2007; v. 35; no. 11; p. 1019–1022; doi: 10.1130/G24141A.1; 3 fi gures; 1 table; Data Repository item 2007250. © 2007 The Geological Society of America. For permission to copy, contact Copyright Permissions, GSA, or [email protected]. ABSTRACT We report oxygen isotope compositions of phenocrysts and U-Pb ages of zircons in four large caldera-forming ignimbrites and pos...