ABSTRACT
More than 100 million people around the world today are endangered by toxic concentrations of geogenic arsenic (As) in groundwater, residing in high yielding aquifers hosted in large sedimentary basins. Nevertheless, not all sedimentary aquifers are enriched in groundwater As. The affected basins are preferentially located in orogenic forelands of present or ancient convergent tectonic margins. This correlation suggests that the worldwide distribution of As-enriched groundwater aquifers can be attributed to global-scale geodynamic processes. Elaborating on this hypothesis, we have advocated a model which involves the mobilization of As from its primary source in deep continental crustal materials, its extrusion at the surface in arc magmas, and the subsequent transport of As to foreland sedimentary basins that eventually act as the groundwater As-enriched aquifers.
