Abstract Although one of the most extensively surveyed areas on earth, there remains extensive debate on the origin, nature and evolution of the crust in the deep Gulf of Mexico (GoM). Key reasons include a lack of basement penetration by drilling (reflecting the thick sediment cover that makes the basin prospective), and inadequate deep imaging data from seismic refraction, magneto-tellurics, and other geophysical techniques. The interpretation of potential fields data is complicated but can provide important constraints on deep crustal structure when combined with analysis of the shape and stratigraphic fill of the basin. The geometry and the nature of the Mohorovicic Discontinuity (Moho) can be constrained using an integrated and iterative approach that considers lithospheric flexure and isostasy, melt generation as a function of crustal thinning, and dynamic topography while honoring the gravity and the refraction data.

Full article available in PDF version.

Abstract As a consequence of environmental and health consciousness that began in the 1970s and continues unabated to this day, several common minerals have become suspect as agents of cancer and other diseases. Many mine dumps have been placed on the Environmental Protection Agency's (EPA) Superfund list for future cleanup, because some of the minerals contained in these dumps are assumed to be hazardous to human health. Better environmental controls were certainly needed in many of our basic mining, smelting, steel, and chemical industries, and much progress has been made in recent years in reducing industrial emissions. However, some of the newly instituted (and excessively restrictive in the view of many) regulatory controls are the result of an extreme overreaction to perceived health risks that are in fact insignificant or nonexistent.