Weathering of Devonian monzogranites as recorded in the geochemistry of saprolites from the South Mountain Batholith, Nova Scotia, Canada

Abstract

Parent mineralogy, paleoenvironment, and subsequent diagenetic and erosional history contribute to the nature of the paleoweathering profiles (saprolites) developed on the South Mountain Batholith. Saprolites of three different ages (pre-Carboniferous, pre-Triassic, and pre-Pleistocene) developed on Devonian monzogranite and exhibit increases in oxidation and hydration and decreases in rare earth elements with increasing weathering. In addition, changes in Ca, Ba, Rb, Zn, Pb, Co, and other elements in the oldest saprolite indicate element mobility during weathering. Re-exposure of these partially weathered profiles at surface in today's acidic and oxygen-rich environment may result in further migration of elements from these saprolites.