River water samples collected from 78 watersheds rivers along a 500-km transect across a Late Cretaceous-Tertiary andesitic volcanic arc terrane in west-central Panama provide a synoptic overview of riverine geochemistry, chemical denudation, and CO2 consumption in the tropics. D/H and 18O/16O relationships indicate that bedrock dissolution of andesitic arc crust in Panama is driven by water-rock interaction with meteoric precipitation as it passes through the critical zone, with no evidence of a geothermal or hydrothermal input. Sr-isotope relationships suggest a geochemical evolution for Panama riverine waters that involves mixing of bedrock pore water with water having 87Sr/86Sr ratios between 0.7037-0.7043 and relatively high Sr-contents with waters of low Sr content that enriched in radiogenic Sr that are diluted by infiltrating rainfall to variable extents.
|Title||Isotopic geochemistry of Panama rivers|
|Authors||Russell S. Harmon, Gerhard Worner, Michael Pribil, Zoltan Kern, Istvan Forizs, W. Berry Lyons, Christopher B. Gardner, Steven T. Goldsmith|
|Publication Subtype||Journal Article|
|Series Title||Procedia Earth and Planetary Science|
|Record Source||USGS Publications Warehouse|
|USGS Organization||Central Mineral and Environmental Resources Science Center|