Beryllium-10-derived denudation rates in the Roda Catchment, Germany

Topographic and lithologic control on catchment-wide denudation rates derived from cosmogenic 10Be in two mountain ranges at the margin of NE Tibet

Spatial distribution of cosmogenic 10Be derived denudation rates between the Western Tian Shan and Northern Pamir, Tajikistan

10Be-derived denudation rates from the Burdekin catchment: The largest contributor of sediment to the Great Barrier Reef

Quantifying denudation rates and sediment storage on the eastern Altiplano, Bolivia, using cosmogenic 10Be, 26Al, and in situ 14C

Using cosmogenic isotopes and solute load analysis, we quantify chemical weathering (solutional erosion) and denudation rates over variable time scales in a tectonically stable, moderate-relief, carbonate terrain (Soreq drainage, Judea Hills, Israel), located in a semihumid Mediterranean climate. Long-term (>10 4 yr) denudation rates were calculated from 36 Cl concentrations in 51 bedrock and sediment samples. Bedrock samples range in elevation (340–850 m), hillslope gradient (0°–30°), and mean annual precipitation (MAP; 500–630 mm) and vary in soil cover thickness (0–75 cm), Mg/Ca ratio (0.0–1.0 mol), clay mineral contents (0–6 wt%), and mechanical strength (41–58 Schmidt hammer rebound units). Soil pCO2 values at a single location during the course of 1 yr, range between 0.4 and 9.0 mmol mol –1 . Average long-term denudation rate of exposed bedrock samples is 21 ± 7 mm k.y. –1 . Field observations and 36 Cl measurements indicate that soil pockets undergo cycles in the rate of deepening, and that over 10 5 yr time scale, average denudation rates beneath soil pockets are similar to those of exposed bedrock. Sediment samples yield even higher denudation rates, which are probably anthropogenically induced, but could also indicate that the sediment source is soil pockets. Long-term denudation rates are decoupled from hillslope gradient, elevation, and rock strength. Denudation rates show a positive correlation with present-day MAP values, exhibit a complex relation with rock Mg content, and show a weak correlation with clay content. Annual chemical weathering rates were calculated from modern-day solute load measured in waters of perched springs and the regional carbonate aquifer. Our results indicate that on annual, decadal, and 10 4 yr time scales, chemical weathering and denudation are controlled by carbonate dissolution, while mechanical processes are far less signifi cant. Overlap between the distributions of HCO3 – concentrations measured in runoff, springs, and the regional aquifer water suggests that chemical weathering focuses at the bedrock surface and therefore is comparable with solutional denudation. This result is in contrast to the features of ancient fl uvial and colluvial activity (steep nonconcave hillslopes and stream profi les and knickzones in the streams) preserved in the present landscape. Such features were formed in response to mid-Pleistocene uplift and could have been preserved due to a decrease in stream power following the formation of subsurface drainage and the lowering in abrasive clast supply that followed the stabilization of hillslopes in the drainage. Long-term denudation rates calculated from exposed bedrock samples are higher by factor of 1.4 relative to annual, contemporary chemical weathering rates. Increased precipitation by a similar factor, averaged over the last glacial and present interglacial, can explain this difference.

Geomorphic disequilibrium in the Eastern Korean Peninsula: Possible evidence for reactivation of a rift-flank margin

Denudation rates and the degree of chemical weathering in the Ganga River basin from ratios of meteoric cosmogenic 10Be to stable 9Be

Cosmogenic 10 Be denudation rates and geomorphometric analysis in the Ambato range (28°–29°S), Sierras Pampeanas, Argentina

Abstract. Disentangling the influence of lithology from the respective roles of climate, topography and tectonic forcing on catchment denudation is often challenging in mountainous landscapes due to the diversity of geomorphic processes in action and of spatial and temporal scales involved. The Dora Baltea catchment (western Italian Alps) is an ideal setting for such investigation, since its large drainage system, extending from the Mont Blanc Massif to the Po Plain, cuts across different major lithotectonic units of the western Alps, whereas this region has experienced relatively homogeneous climatic conditions and glacial history throughout the Quaternary. We acquired new 10Be-derived catchment-wide denudation rates from 18 river-sand samples collected both along the main Dora Baltea river and at the outlet of its main tributaries. The inferred denudation rates vary between 0.2 and 0.9 mm yr−1, consistent with previously published values across the European Alps. Spatial variability in denudation rates was statistically compared with topographic, environmental and geological metrics. 10Be-derived denudation rates do not correlate with modern precipitation and rock geodetic uplift. We find, rather, that catchment topography, in turn conditioned by bedrock structures and erodibility (lithotectonic origin) and glacial overprint, is the main driver of 10Be-derived denudation patterns. We calculated the highest denudation rate for the Mont Blanc Massif, whose granitoid rocks and long-term tectonic uplift support high elevations, steep slopes and high relief and thus favour intense glacial and periglacial processes and recurring rockfall events. Finally, our results, in agreement with modern sediment budgets, demonstrate that the high sediment input from the Mont Blanc catchment dominates the Dora Baltea sediment flux, explaining the constant low 10Be concentrations measured along the Dora Baltea course even downstream the multiple junctions with tributary catchments.

We evaluate spatial and temporal variations in denudation of the north-central Wasatch Mountains, Utah, by determining catchment-wide denudation rates with 10Be concentrations in alluvial sediment and comparing these rates with previously published data on rock uplift and exhumation of the range. Catchments draining the range front show relatively little variation in denudation rate (0.07–0.17 mm/yr), while steeper (mean hillslope gradient >30°) catchments in the core of the range show larger variation (0.17–0.79 mm/yr). We attribute the larger spatial variation in catchment-wide denudation in the core of the range to landsliding of hillslopes at threshold gradients; faster denudation in this region may signify landscape adjustment to late Pleistocene glaciations. The mean denudation rate for all catchments (0.2 mm/yr) is generally consistent with longer-term exhumation rates derived from thermochronometers and with shorter-term vertical fault displacement rates, suggesting that denudation of the north-central Wasatch has been roughly steady, or decreasing slightly, over the past 5 m.y. Although 10Be-based catchment-wide denudation rates are sensitive to localized geomorphic processes and events, overall, they appear to reflect the larger tectonic forces that have driven denudation of the Wasatch Mountains over longer time scales.

Late-Pleistocene catchment-wide denudation patterns across the European Alps

The Longmen Shan range, located on the eastern margin of the Tibetan Plateau, is characterized by steep topography and a shortening rate of <3 mm/yr. This peculiar configuration is a source of controversy and questions about the topographic evolution and dynamics of this orogenic plateau margin. Investigating the variations in surface denudation over different spatial and temporal scales is important for a better understanding of topographic evolution, but there is still a lack of erosion‐rate data averaged over millennial timescales along the frontal range of the Longmen Shan, especially in its southern part. We present 25 new catchment‐wide denudation rates derived from 10Be concentrations in river sediments across the southern Longmen Shan. Our results show that average denudation rates increase from <0.15 mm/yr near Ya'an, located in the Sichuan Basin, northwestward to >0.50 mm/yr inside the southern Longmen Shan. The denudation rates correlate with slope gradient, relief, channel steepness, and specific stream power but exhibit a fair degree of scattering at high values. In combination with previous 10Be and low‐temperature thermochronology analyses, we found the denudation rates over kyr‐ to Myr‐timescales to be roughly consistent across the southern Longmen Shan, suggesting this part of the range is close to an exhumational steady state. In terms of spatial distribution, high rates of exhumation and denudation are localized in the hanging walls of major thrust faults, highlighting the role of tectonic structures in regulating the pattern of denudation and topography across the Longmen Shan. Our results favor the “brittle crustal shortening” model in which rock uplift pattern across the Longmen Shan is largely controlled by upper crustal shortening. Along‐strike variations in the distribution of denudation rates and topography can probably be attributed to segmentation of subsurface fault structures.

Frost-cracking control on catchment denudation rates: Insights from in situ produced 10Be concentrations in stream sediments (Ecrins–Pelvoux massif, French Western Alps)

Assessing the effect of a major storm on 10BE concentrations and inferred basin-averaged denudation rates

Spatial and temporal variations in denudation rates derived from cosmogenic nuclides in four European fluvial terrace sequences