VARIOUS EROSION RATES OF WEATHERED GRANITIC SOIL SURFACES IN ABUKUMA, EASTERN JAPAN USING in-SITU TERRESTRIAL COSMOGENIC NUCLIDE DEPTH PROFILE

We present erosion rates of weathered granitic soil surfaces in Abukuma, eastern Japan using a depth profile of in-situ produced cosmogenic ¹⁰Be and ²⁶Al. Multiple-depth profiles of in-situ produced cosmogenic nuclides constitute a powerful tool for directly, accurately, and quantitatively determining erosion rates of weathered soil surfaces of mountain ridges in humid areas (e.g., Shiroya et al., 2010; Nakamura et al., in prep.). Abukuma is a well-known study area for fore-arc tectonics. However, the relationship between landform evolution and both tectonics and climate has not been quantitatively discussed. In this study, we investigate erosion rates of mountain ridges. Results show that the study sites have much lower erosion rates than previous studies (Shiroya et al., 2010; Nakamura et al., in prep.).This suggests that erosion rates in Abukuma area are not uniform. In this presentation, we will discuss of causes of heterogeneous erosion rates in the Abukuma area.