The realization that Earth may have lost heat more slowly in the past than at present has motivated the search for mechanisms to reduce the efficiency of plate tectonics in the past. Several mechanisms have been proposed, such as the resistance to subduction of thick plates (1) produced by deeper melting at higher mantle temperatures (2). We (3) proposed an alternative mechanism, namely subduct...

erosion phenomenon (plate tectonics process) CESA'98 Nabeul-Hammamet, Tunisia, April 1998 Thomas LEDUC September 1997

The Earth stands out in the solar system as the only planet with plate tectonics. This peculiarity is due not only to strong internal heating but also a lithosphere rheology characterized by brittle failure and localization, as a comparison with Venus clearly show. Localization in the ductile regime are manifested on Earth by ductile shear zones, which have proven difficult to explain theoretic...

EARTHQUAKE SOURCE PARAMETERS, SEISMICITY, AND TECTONICS OF THE OCEANOGRAPHER TRANSFORM FAULT

The Earth Materials Area is comprises the Experimental Petrology, Rock Physics, Thermochronology and Structure & Tectonics Groups. The research of these groups centres around laboratory based measurements under controlled conditions, simulating those occurring in nature, but these activities are complimented by field based observations, often in collaboration with scientists from other institut...

New fieldwork and tectonic analysis has been carried out along the Andean morphotectonic frontline between 46°30’ 47°30′S. The right lateral transtensional Marques–Zeballos Pass fault system (MZPRS) controlled 800–1200 m uplift of Andes at 16.1–18.1 Ma. Our data indicate that there was no lower Miocene contractile event frontline. Main Thrust (MAT), which is deeply rooted in upper crust a retro...

The Magdalena fan is an apparently beheaded submarine depocenter that has figured prominently in Middle to late Miocene reconstructions of Pacific-North American plate interactions. The deposit accumulated rapidly at the base of the continental slope atop newly formed oceanic crust of the Farallon plate from 14.5-13 Ma. Subduction of this crust ceased as the Pacific-Farallon spreading center en...