Abstract The North Australian Zinc Belt is the largest zinc-lead province in world, containing three of ten known individual deposits (HYC, Hilton-George Fisher, and Mount Isa). Northern Cordillera America second province, a further two world’s top (Red Dog Howards Pass). Despite this world-class endowment, exploration both mineral provinces during past 2 decades has not been particularly succe...

S U M M A R Y Using both numerical experiments and approximate linear theory, we examine the stability of a 2-D, three-layered viscous system that represents crust over mantle lithosphere, overlying asthenosphere. If horizontal shortening of lithosphere occurs, as in mountain building, the development of gravitational instability may follow one of two distinct paths. Localized downwelling occur...

The locations of volcanic islands may be controlled by thin or extending parts of the lithosphere over a partially molten asthenosphere [Anderson and Bass, 1984; Favela and Anderson, 2000], by edge effects near the boundaries of thick cratonic lithosphere [Anderson, 1998], or by narrow jets of hot mantle rising from deep within the mantle [Campbell and Griffiths, 1992; Morgan, 1971; Wilson, 198...

S U M M A R Y Rayleigh wave phase velocities and azimuth anomalies in the period range of 30–100 s are measured for a set of four triangular arrays of broad-band seismometers in coastal northeastern USA. This is a region in which a strong upper mantle slow shear velocity anomaly (a ‘New England Anomaly’), crosses the continental margin. Earthquakes from a wide range of directions are used to de...

Located in the northwestern United States, the Newberry Hotspot Track consists of a sequence of age-progressive silicic volcanic domes and lava flows, showing a monotonic age progression from east to west ending at the Newberry Caldera. While mantle plumes are often called upon to explain hotspot tracks, the Newberry track cannot be the direct product of plate motion over a stationary mantle so...

The presence of diamonds Archaean age within the cratonic lithosphere is surprising because their formation implies a cool early mantle despite Earth's hotter state. There remains widely (albeit not exclusively) held concept that prevailing geothermal gradient cratons was much different from today. This ‘Archaean paradox’ supported by pressure and/or temperature (PT) estimates potentially ancie...

[1] Upper mantle seismic velocity structures in both vertical and horizontal directions are key to understanding the structure and mechanics of tectonic plates. Recent deployment of the USArray Transportable Array (TA) in the Midwestern United States provides an extraordinary regional earthquake data set to investigate such velocity structure beneath the stable North American craton. In this pa...