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...

Small-volume Late Cretaceous monogenetic alkaline volcanism along the southern margin of North America resulted in a broad igneous belt more than 1200 km long from the Trans Pecos region of west Texas to central Mississippi, collectively forming a northern Gulf of Mexico magmatic zone (NGMMZ). The locus of igneous activity is associated with the discontinuity separating Mesoproterozoic cratonic...

Abstract Anatolia is characterised by a complex geodynamic evolution, mirrored wide spectrum of magmatism. Here, we investigated the timing and geochemical/isotopic characters Miocene to Pliocene volcanism Sivas–Malatya Region (Central Eastern Anatolia), its relationships with local regional tectonics. Na-alkaline basaltic lavas were emplaced during middle at Sivas (16.7–13.1 Ma), in North, whi...

[1] The last major phases of lunar volcanism produced spectrally unique high‐titanium basalts on the western nearside of the Moon. The Moon Mineralogy Mapper (M) on Chandrayaan‐1 has provided detailed measurements of these basalts at spatial and spectral resolutions necessary for mineralogical interpretation and mapping of distinct compositional units. The M3 imaging spectrometer acquired data ...