Long-standing debates exist over the timing and mechanism of uplift of the Tibetan Plateau and, more specifically, over the connection between lithospheric evolution and surface expressions of plateau uplift and volcanism. Here we show a T-shaped high wave speed structure in our new tomographic model beneath South-Central Tibet, interpreted as an upper-mantle remnant from earlier lithospheric f...

Tectonic collision between South America and Panama began at 23–25 Ma. The collision is signifi cant because it ultimately led to development of the Panamanian Isthmus, which in turn had wide-ranging oceanic, climatic, biologic, and tectonic implications. Within the Panama Canal Zone, volcanic activity transitioned from hydrous mantle-wedge−derived arc magmatism to localized extensional arc mag...

The enigma of continental plateaus formed in the absence of continental collision is embodied by the Altiplano-Puna, which stretches for 1800 km along the Central Andes and attains a width of 350–400 km. The plateau correlates spatially and temporally with Andean arc magmatism, but it was uplifted primarily because of crustal thickening produced by horizontal shortening of a thermally softened ...

[1] We introduce a quantitative model of global mantle convection that reconstructs the detailed motion of a warm mantle upwelling over the last 30 Ma towards the interior of the southwestern USA from observed present-day mantle heterogeneity. The onset and evolution of uplift in the central Basin and Range province and Colorado Plateau during this time is determined by tracking the topographic...

TheOrdovician volcanic and intrusive rocks of the Cadia–Neville region, in the southern Molong Volcanic Belt section of the Macquarie Arc in central-western New South Wales, display a temporal progression from shoshonitic basaltic volcanism (e.g. Mt Pleasant Basalt Member) in the late Darriwilian to Gisbornian (ca 460–453 Ma) to small-volume dacitic medium-K calc-alkaline magmatism (e.g. Copper...

Geological observations that constrain the history of mantle convection are sparse despite its importance in determining vertical and horizontal plate motions, plate rheology, and magmatism. We use a suite of geological and geophysical observations from the northern North Sea to constrain evolution of the incipient Paleocene-Eocene Icelandic plume. Well data and a three-dimensional seismic surv...

Slab breakoff is the buoyancy-driven detachment of subducted oceanic lithosphere from the light continental lithosphere that follows it during continental collision. In a recent paper Davies and von Blanckenburg [1994] have assessed the physical conditions leading to breakoff by quantitative thermomechanical modeling and have predicted various consequences in the evolution of mountain belts. Br...

The East African Rift System transects the anomalously high-elevation Ethiopian and East African plateaux that together form part of the 6,000-km-long African superswell structure. Rifting putatively developed as a result of mantle plume activity that initiated under eastern Africa. The mantle activity has caused topographic uplift that has been connected to African Cenozoic climate change and ...

Recem Ocean Drilling Program sampling of the Ctte d'Ivoire-Ghana margin of West Africa provides for the first time the opportunity to study the development of a marginal ridge that formed along a sheared passive margin adjacent to the continent-ocean transition after the end of intmcontinemal wrenching. We model its evolution using a two dimensional flexural backstripping technique. The model i...