Carbonatitic high-density fluids and carbonate mineral inclusions in lithospheric sub-lithospheric diamonds reveal comparable compositions to crustal carbonatites and, thus, support the presence of carbon-atitic melts depths at least mantle transition zone (~410–660 km depth). Diamonds high pressure–high temperature (HP–HT) experiments confirm stability lower carbonates. Experiments also show t...

Most seismological models for the interior of Mars lack an upper mantle low velocity zone. However, there is expected to be a large thermal gradient across the stagnant conductive lid (lithosphere) of Mars. This gradient should tend to decrease elastic wave velocities with increasing depth, with this effect dominating the opposing tendency caused by increasing pressure with depth because Mars h...

Article history: Received 29 March 2017 Accepted 27 July 2017 Available online 04 August 2017 Subduction and collision are the key processes triggering geochemical refertilization of the lithospheric mantle beneath cratons. However, the way that the subducted plate influences the cratonic lithospheric mantle remains unclear. Here, in-situ major and trace-element and Sr isotopic compositions of ...

Acquisitionof teleseismicdata in south-westernNewSouthWalesduring2007 formed the latest stageof a rolling deployment of seismometers over south-easternAustralia, and allowed a revised tomographicmodel to be constructed for the lithospheric mantle under Victoria and southern NSW. Our aim here is to link the observed distribution of upper-mantle P-wave velocity to the major geological features of...

The Cameroon Volcanic Line (CVL) straddles the continent-ocean boundary in West Africa but exhibits no clear age progression. This renders it difficult to explain by traditional plume/plate motion hypotheses; thus, there remains no consensus on the processes responsible for its development. To understand better the nature of asthenospheric flow beneath the CVL, and the effects of hotspot tecton...

The Precambrian geological record shows peak of activity at 1.1, 1.9–2.1, 2.7 and 3.5 Ga, often associated with massive crustal production, orogenesis and supercontinent cycles. It has been suggested that these bursts of tectonic activity are due to mantle avalanche events, where accumulating subducted slabs periodically penetrate the 670 km discontinuity, and subsequent upwelling counterflow a...

s CD. BODINIER, J.-L., MENZIES, M. A., SHIMIZU, N., FREY, F. A. & MCPHERSON, E. 2004. Silicate, hydrous and carbonate metasomatism at Lherz, France: contemporaneous derivatives of silicate melt–harzburgite reaction. Journal of Petrology, 45, 299–320. BONADIMAN, C., BECCALUVA, L., COLTORTI, M. & SIENA, F. 2005. Kimberlite-like Metasomatism and ‘garnet signature’ in spinel-peridotite xenoliths fr...

Two issues (Parts I and II) of Rocky Mountain Geology (RMG) are an attempt to summarize the structure and evolution of the continental lithosphere in a Rocky Mountain transect from Wyoming to New Mexico (Fig. 1). After decades of geologic work, our understanding of the complex history of this region is still incomplete. As in many other regions, firstorder questions remain about the deep struct...

[1] The presence of deeply penetrating continental roots may locally increase the magnitude of basal shear tractions by up to a factor of 4 compared to a layered viscosity structure. Here we examine how these increases in mantlelithosphere coupling influence stress patterns in the overlying elastic lithosphere. By coupling a mantle flow model to a model for the elastic lithosphere, we show that...

Internal processes operating within low-density satellites, although they are poorly understood at present, are extremely significant in determining the scale and type of surface processes and features and the geologic evolution of such satellites. The two Galilean satellites Ganymede and Callisto are examples of such low-density (p < 2) bodies, and they are likely to have undergone a thermal e...