Nuttakan Wongfun (ETH
Zürich, Switzerland)
"Weathering of granite rock in the Damma glacier forefield"
Abstract
Mobilization of
nutrients from rock through weathering processes plays a crucial role to
overcome the limitation of nutrient in the glacier forefield. Microorganisms
and plants modify their local environment by various exudates including
cyanide, which is a very important agent during the initial period of
colonization and soil formation. We study the weathering mechanisms of
primary rock-forming minerals. Rock and weathered stream sediments were
obtained from the Damma glacier area. Qualitative conclusions on different
water regimes result from variations in hydrological factors, such as water
availability and degree of physical protection. The mineralogical
characterization of the sediments from the forefield also revealed trends in
physical weathering processes and consequently in the availability of
nutrients. The study of dissolution experiments under controlled conditions
showed the presence of cyanide caused a suppression of iron in comparison to
cyanide-free conditions.