Topography and gravity measured by the Mars Global Surveyor have enabled determination of the global crust and upper mantle structure of Mars. The planet displays two distinct crustal zones that do not correlate globally with the geologic dichotomy: a region of crust that thins progressively from south to north and encompasses much of the southern highlands and Tharsis province and a region of ...

The mechanics and petrological signature of a collisional mountain belt can be significantly influenced by topographic and erosional effects at the scale of large river gorges. The geomorphic influence on crustal scale processes arises from the effects of both stress localization due to existing topography, and also erosional removal of advected crustal mass. The shear stress concentration and ...

The topography associated with the fundamental crustal dichotomy in much of eastern Mars can be largely ascribed to a single event: the very large impact which produced the Utopia Basin. Subsequent internal and surficial processes have been unable to remove the topographic signature of this basin. In particular, endogenic processes appear to have been ineffective in contributing to the basic di...

We model crustal deformation and the resulting thermal structure across the Nepal Himalaya, assuming that, since 20Ma, shortening across the range has been primarily taken up by slip along a single thrust fault, the Main Himalayan Thrust (MHT) Fault, and that the growth of the Himalayan wedge has resulted mainly from underplating and to the development of a duplex at midcrustal depth. We show t...

The rock-hosted, oceanic crustal aquifer is one of the largest ecosystems on Earth, yet little is known about its indigenous microorganisms. Here we provide the first phylogenetic and functional description of an active microbial community residing in the cold oxic crustal aquifer. Using subseafloor observatories, we recovered crustal fluids and found that the geochemical composition is similar...

tehran, iran’s capital with a population of more than 10 million is located in the southern foothills of the alborz collision zone. the alborz mountain belt of northern iran results from the collision of a piece of the gondwana with eurasia in the late triassic (sengor et al., 1988). the alborz active mountain range which consists of several sedimentary and volcanic layers, with east-west trend...

The potential effects of continental crust on mantle convection are explored using threedimensional numerical simulations. The simulations model the coupling between a thin, deformable layer of chemically buoyant crust and a deep layer of thermally convecting and chemically dense mantle. Simulations begin with a crustal layer embedded within the upper thermal boundary layer of a mantle convecti...

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...

[1] PS converted waves observed near Ancona on the Adriatic coast of central Italy, as revealed by teleseismic receiver functions (RFs), vary with earthquake backazimuth and epicentral distance in a manner consistent with a 1-D anisotropic seismic structure. Using reflectivity calculations, we develop a profile of anisotropic seismic velocity through the Adriatic lithosphere at this locality. W...

This paper focuses on acoustic reflectivity of the ocean bottom, and describes inversion of reflection data from an experiment designed to study the physical properties and structure of the ocean bottom. The formalism of Bayesian inference is reviewed briefly to establish an understanding of the approach for inversion that is in widespread use. A Bayesian inversion of ocean bottom reflection co...