This data publication is supplementary to a study on the effect of large boulders and bedrock fracture patterns on hillslope denudation rates in the Chilean Coastal Cordillera, by Lodes et al. (submitted). Hillslope denudation rates are primarily determined by tectonic uplift rates, but landscape morphology is also controlled by climate and lithological properties such as bedrock fractures. Fracture patterns can influence the locations of ridges and valleys in landscapes through lowering surface grain sizes in fractured areas, and therefore the residence time of fractured hillslope material, dictating differential denudation rates. In this project, we used 10Be cosmogenic nuclide analysis to quantify the denudation rates of fractured bedrock, boulders, and soil on hillslopes, and compared the orientations of surrounding streams and faults, to understand the effects of fracturing and faulting on denudation rates, fluvial incision, and grain size in three field sites along a climate gradient in the Chilean Coastal Cordillera. In the humid and semi-arid climate zones, we found that denudation rates for unfractured bedrock and large hillslope boulders (10 to 15 m Myr-1) are lower than for soil (15 to 20 m Myr-1), indicating that exposed bedrock and boulders retard hillslope denudation rates. In the mediterranean climate zone, hillslope denudation rates are higher (40-140 m Myr-1) and show a less consistent pattern, likely due to steeper slopes. LiDAR-derived stream orientations support a fracture-control on landscape denudation in the three field sites, which we link with fracture density. Together, our results thus provide new insights into how fracture patterns can dictate topographic highs and valleys through grain size reduction. The main objective of this data publication is to provide our 10Be dataset which we used to calculate denudation rates for bedrock, boulders, and soils.

We conducted fieldwork in Chile in February 2019 and March 2020. We collected 32 samples from bedrock, boulders, and topsoil in three field areas (Nahuelbuta National Park, La Campana National Park, and Private Reserve Santa Gracia) for cosmogenic 10Be analysis. A detailed description of the field areas can be found in Lodes et al. (submitted). We collected bedrock samples by chipping off and amalgamating 10-15 pieces (~25 cm2 and <2cm thick) of bedrock in an area of ~20 m x 20 m. Boulder samples consist of similarly-size chips from 10-15 different boulders of similar size, from an area of ~40 m x 40 m, depending on the abundance of boulders. We collected soil samples from the area surrounding the sampled boulders. The samples are assigned with IGSNs, which are listed in the accompanying data table 2022-004_Lodes-et-al_Data.