Geoarchaeological Analysis of Floodplain Carbon Cycling and Holocene Landforming Processes Using Buried Soils, Bow River, Southern Alberta
Date
2023-05-03
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Abstract
River processes, like erosion and deposition, and soil forming processes, namely organic matter decomposition and carbon mineralization, operate on land surfaces within floodplains to create distinct depositional layers. Soil horizons buried among floodplain sediment deposits indicate the existence of a former land surface, which can be approximately dated using embedded organic materials to reconstruct coarse land formation timelines. These soil and sediment layers may also be the deposition matrix for archaeological and paleontological materials that comprise the geoarchaeological record in a floodplain. A wealth of recent research on the paleoenvironmental and archaeological records within the Bow River watershed was published following the monumental flooding and subsequent geomorphological impacts that occurred in June of 2013. My research aims to combine these existing studies with additional primary empirical research to contribute to the reconstruction of Holocene channel evolution in the Bow River watershed and to advance knowledge regarding the role that floodplain soils occupy in carbon sequestration. Data derived from a laboratory analysis of sediment samples collected along the banks of the Bow River were interpreted using a combination of established theoretical frameworks regarding stratified floodplain sediment storage spanning the disciplines of archaeology and geomorphology. Analysis at one site shows that a fluventic soil and sediment profile formed approximately 3000 years ago from cyclical overbank flooding and deposition and subsequent stability and soil development. The soils likely developed over decades in which there was relative stability on the floodplain, which is not unlike the scale of cyclical flooding observed in the watershed since colonization. Floodplain soil and sediment profiles may have different carbon storage potential than upland soils due to unique vertical soil organic carbon content distributions. Comparing the vertical distribution of soil organic carbon between floodplain and upland soils showed a difference in carbon sequestration potential between upland and floodplain environments in the region and pointed towards fluvial processes being a driver in creating this difference. This research contributes new data and knowledge regarding the magnitude and mechanisms of floodplain carbon cycling, specifically in the context of the Northern Great Plains, plus enrich contextual knowledge of regional geoarchaeology.
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Geoarchaeology, Bow river, Fluvial geomorphology, Wandering gravel bed river, Flood of 2013
Citation
Serviss, K. A. C. (2023). Geoarchaeological analysis of floodplain carbon cycling and holocene landforming processes using buried soils, Bow River, Southern Alberta (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.