Mapping and Assessing Seasonal CO2 Flux from Dissolution of Alpine Carbonates
Concerns about global climate change have focused on increasing levels of atmospheric CO2 in relation to the carbon budget. Natural components of the carbon cycle such as tectonic uplift and weathering of silicates and carbonates are thought to be an important component of this system, but they are only partly understood. Many of the underpinnings of the carbon cycle need re-evaluation. For example, the deposition, precipitation, and cementation of carbonates produce reservoirs of CO2. These sources can be transported while equilibrating. The interactions stabilize the CO2 creating a sink in aqueous media. This counterbalances the weathering and dissolution of carbonates releasing atmospheric CO2. Many variables, such as soil microbes and CO2 uptake by plants mediate the exchange between CO2 sinks and the atmosphere, but in alpine and high-latitude settings, where carbonate lithosomes may be exposed, weathering carbonates interact directly with the atmosphere. Carbon dioxide outgassing and surface exposures are measurable components in these settings, but the contribution is seasonal due to snow and ice cover. Seasonal changes bring variations in aqueous solutions. With mixing of waters and transport a range of CO2 concentrations will create carbonate interactions that have yet to be identified and measured. Massive carbonate lithosomes exposed above treeline in the Canadian Rockies provide a remarkable opportunity to calculate surface area of terrestrial and atmospheric interactions. The underlying bedrock allows stabilization of carbon ions from the cations weathered from the siliclastic igneous rock. The final CO2 concentrations within high altitude carbonate systems should be greatly variable because of the seasonal change, measuring this change is the next step. The Canadian Rockies are a specific case, producing more detailed carbon interaction data will expand our understanding of the processes within global carbon interactions.
AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009