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

Denudation is a key geomorphological process shaping landscapes. In-situ-produced cosmogenic ¹⁰Be has been used to quantify millennial denudation rates worldwide. Long-term denudation rates in the European lowlands can provide valuable insights into the roles of periglacial processes and human activity in landscape evolution. Here, we quantify local and catchment-wide denudation rates in the Roda Catchment in Thuringia, central Germany. Specifically, we constrain 17 catchment-wide denudation rates based on ¹⁰Be concentrations in river sediments and 5 local denudation rates based on ¹⁰Be concentrations from soil samples on the flat catchment divides. Catchment-wide denudation rates vary between 23.8 ± 5.4 and 79 ± 18 mm kyr⁻¹, and local denudation rates range from 23.4 ± 5.6 to 41.9 ± 9.8 mm kyr⁻¹. These catchment-wide denudation rates are consistent with published European data, which are generally higher than those reported from other regions worldwide. This difference can be attributed to periglacial dynamics during the last glacial period. The ¹⁰Be-derived long-term denudation rates in Europe are generally higher than recent, short-term erosion rates, despite vast human activities and intensive land use in recent decades. This could be due to past periglacial activity; large-scale forest clearance during the Roman and Medieval times; and the limitations of short-term measurements in capturing low-frequency, high-magnitude events. The observed differences between catchment-wide and local denudation rates suggest that denudation has led to changes in topographic relief in the Roda Catchment at a mean rate of 0–28 mm kyr⁻¹ over the past 10 ka.

1 Introduction

Denudation is associated with various physical, chemical, and biological processes that can shape landscapes (Allen, 2008). Quantifying denudation rates is important for investigating landscape evolution and its controls. Conventional approaches to estimating denudation rates at catchment scales are mainly based on field measurements of dissolved and suspended loads in streams, typically over timescales of decades (e.g., Clayton and Megahan, 1986). However, such gauging approaches may fail to capture rare extreme events, and the derived denudation rates may not represent denudation rates over geological (millennial) timescales (Milliman and Meade, 1983; Lenzi and Marchi, 2000; Granger and Riebe, 2014).

In-situ-produced cosmogenic nuclides can be used to constrain long-term denudation rates in a variety of settings (Nishiizumi et al., 1986; Lal, 1991; Bierman and Turner, 1995; Brown et al., 1995; Bierman and Steig, 1996; Granger et al., 1996). The principle of this method is that concentrations of cosmogenic nuclides are inversely proportional to the denudation rate of an eroding surface (Nishiizumi et al., 1986; Lal, 1991). Cosmogenic nuclides were initially used to quantify local bedrock denudation and soon extended to the catchment scale to estimate catchment-wide denudation rates from nuclide concentrations in river sediments (Brown et al., 1995; Bierman and Steig, 1996; Granger et al., 1996; von Blanckenburg, 2005). Since then, in-situ-produced cosmogenic nuclides, particularly ¹⁰Be measured in quartz, have been widely used to constrain denudation rates at the catchment scale.

Previous studies have shown that denudation rates are influenced by various factors, including topography, climate, vegetation, lithology, and tectonics. Carretier et al. (2013), for example, used both suspended-load measurements and ¹⁰Be-derived denudation rates along an exceptional climatic gradient in the Andes of central Chile and found that slope is the primary control on denudation. Based on data for the European Alps, Delunel et al. (2020) also highlighted a close relationship between slope and denudation. The effects of precipitation and vegetation on denudation remain controversial. Starke et al. (2020) found both positive and negative correlations between denudation and vegetation using 86 ¹⁰Be-derived denudation rates along the western Andean margin. These contrasting observations have been interpreted as resulting from competing effects of precipitation and vegetation on denudation. The complex interactions between climate, vegetation, and denudation have also been proposed by Mishra et al. (2019) and Chen et al. (2022) using global data. Tectonic forcing can significantly accelerate physical erosion and chemical weathering (Riebe et al., 2001; von Blanckenburg, 2005). Temperature-controlled glacial and periglacial erosion processes play an important role in limiting orogen elevations and thereby shaping landscapes (Roda-Boluda et al., 2023). Frost cracking has been identified as a key driver of denudation in the European Alps and other mid-elevation mountain ranges (Delunel et al., 2010). Lithology, as an indicator of bedrock strength, can also exert an important control on denudation (Palumbo et al., 2010; Portenga and Bierman, 2011; Scharf et al., 2013; Ott, 2020).

Cosmogenic-nuclide-derived denudation rates have also been used to explore topographic relief changes. For example, Li et al. (2014) found that the landscape has been relatively stable on the central Tibetan Plateau, while its margins are affected by active fluvial erosion based on ¹⁰Be-derived denudation rates across the Tibetan Plateau and its bordering mountains. The difference between catchment-wide and local denudation rates from flat catchment divides can be used to evaluate topographic relief changes due to denudation over geological timescales (e.g., Hancock and Kirwan, 2007; Meyer et al., 2010b; Wolff et al., 2018; Heineke et al., 2019; Hetzel et al., 2024). Although denudation rates and associated topographic changes have been widely investigated, research remains limited in the European lowlands, particularly in central Germany. Denudation in these regions has been influenced by past periglacial processes and intensive human activities, including extensive farming and deforestation. Quantifying long-term denudation rates in these regions is therefore important for assessing the influence of climate and human activity on landscape evolution.

Figure 1 Topographic map of the Roda Catchment, showing sub-catchments, sample locations, and sample IDs next to the sample locations. Fluvial (river sand) samples are shown as black circles, and soil samples are shown as red rectangles. The black circle near sample 13 marks the viewpoint of the photo in Fig. 2a.

For this study, we collected quartz-rich samples for ¹⁰Be analysis from a low-relief catchment, the Roda Catchment, in central-eastern Germany. We constrained 17 catchment-wide and 5 local denudation rates based on the ¹⁰Be concentrations in river sediments and surface soils from flat catchment divides, respectively. By combining our results with global denudation records from the Octopus database (Codilean et al., 2018; Codilean et al., 2022; Codilean and Munack, 2025) and global short-term erosion rates (Chen et al., 2022), we aim to explore (1) the influence of periglacial activities on denudation by analyzing European denudation rates in the context of existing global data, (2) the impact of human activity on short- and long-term erosion rates by comparing long-term ¹⁰Be-derived denudation rates with decadal erosion rates in central Europe, and (3) long-term changes in the topographic relief of the Roda Catchment resulting from denudation.

2 Material and methods

2.1 Study area

The Roda Catchment is located a few kilometers southeast of Jena in Thuringia, Germany (Fig. 1). The Roda River is a tributary to the Saale. The bedrock within the Roda Catchment mainly consists of siliciclastic sedimentary rocks (Buntsandstein; Hartmann and Moosdorf, 2012). The overall relief does not exceed 260 m: the uppermost parts are mostly flat (Fig. 2d), while incision of the Roda River and its tributaries (e.g., Fig. 2e) at least partly leads to steep slopes. The climate is temperate oceanic with a mean annual temperature of ∼ 8 °C and with mean annual precipitation of ∼ 660 mm (Fick and Hijmans, 2017). The main land use types are forest and farmland (Figs. 1 and 2). KMZ files in the Supplement are provided to visualize the catchments and sampling sites in Google Earth.

Figure 2 (a) Photographic view of the Roda Catchment facing northwest; the viewing direction and photo location are indicated in Fig. 1. (b) The river from which sample 3 was collected. (c) Confluence of two tributaries; samples 5 and 6 were collected from the individual tributaries. (d) Flat catchment divide where soil sample 10 was collected. (e) Fluvial incision observed near sample 12. (f) Humanmade stone revetment upstream of sample 4.

2.2 Sampling and sample processing

A total of 22 ¹⁰Be samples were collected: 17 river sand samples and 5 soil samples (Figs. 1 and 2). River sand samples were taken from active streams. There are no extensive terraces and floodplains in the Roda Catchment, indicating low sediment storage within the catchment. Soil samples were collected from flat agricultural fields near the catchment divides. All soils are very sandy and rich in quartz.

Samples were first sieved to 250–710 µm, and quartz was enriched and purified using HCl (32 %), magnetic separation, and a mixture of 1 : 1 (by volume) of H₂SiF₆ (35 %) and HCl (32 %) (Brown et al., 1991; Merchel et al., 2019). We then partially dissolved the samples three times (∼ 10 % each step) using HF (48 %) to remove meteoric ¹⁰Be (Brown et al., 1991). About 0.36 mg ⁹Be was added to every ∼ 50 g quartz sample and processing blank. More information about our self-made ⁹Be carrier is provided in Appendix A. The samples were dissolved in 48 % HF at room temperature using high-density polyethylene bottles placed on a shaker table. They were then fumed three times with HNO₃ (> 65 %) and then three times with HCl (32 %). Thereafter, beryllium was separated by anion and cation exchange chromatography and pH-selective precipitation (Merchel and Herpers, 1999), oxidized to BeO, mixed with Nb (1 : 2 by weight), and finally pressed in copper accelerator mass spectrometry (AMS) targets using Cu pins. The AMS analyses were performed at the Vienna Environmental Research Accelerator (VERA) facility with a dedicated ¹⁰Be detector described by Steier et al. (2019). The ¹⁰Be $/$ ⁹Be ratios were normalized to the in-house standard SMD-Be-12 with ¹⁰Be $/$ ⁹Be = (1.704 ± 0.03) × 10¹² (Akhmadaliev et al., 2013), which is traceable to the NIST 4325 standard material (Nishiizumi et al., 2007).

Figure 3 (a) Location of the Roda Catchment. (b) Calculated catchment-wide denudation rates are shown in black numbers and shaded in brown, and local denudation rates are shown in red numbers. (c) Boxplot for local and catchment-wide denudation rates. The white lines within the boxes indicate mean values. See Table 2 for associated uncertainties.

2.3 Catchment-wide denudation rate calculations

For an eroding surface, the cosmogenic nuclide concentrations in mineral grains decrease with increasing denudation rates, and for commonly used cosmogenic radioactive nuclides, ¹⁰Be and ²⁶Al, this relationship can be described by the following equation (e.g., Lal, 1991):

$$\begin{array}{}\text{(1)}& N_i\left(z\right)=\sum _{x=\mathrm{sp},\mathrm{fm},\mathrm{sm}}{\displaystyle \frac{P_{i,x}\left(\mathrm{0}\right)}{{\mathit{\lambda }}_i+\frac{\mathit{\epsilon }}{{\mathrm{\Lambda }}_x}}}\cdot e^{-\frac{z}{{\mathrm{\Lambda }}_x}},\end{array}$$

where N_i is the nuclide concentration of cosmogenic nuclide i (atoms g⁻¹), and z and ε are the mass depth (g cm⁻²) and mass denudation rate (g cm⁻² yr⁻¹), respectively. x stands for three nuclide production pathways: high-energy neutron spallation (sp), slow muon (sm) capture, and fast muon (fm) interactions. P_i,x(0) is the production rate of nuclide i by production pathway x at the surface (z=0) (atoms g⁻¹ yr⁻¹), λ_i is the decay constant of nuclide i (yr⁻¹), and Λ is the attenuation length of the production pathway x (g cm⁻²) (Lal, 1991; Gosse and Phillips, 2001). This model assumes that (a) the production rates of cosmogenic nuclides decrease exponentially with depth in soil or rock, (b) the initial cosmogenic nuclide concentrations are negligible, (c) the denudation is in steady state, and (d) the surface has been continuously exposed to cosmic rays for a long period of time, i.e., $t\gg \mathrm{1}/(\mathit{\lambda }+\mathit{\epsilon }/\mathrm{\Lambda }$) (e.g., Lal, 1991; Granger and Riebe, 2014; Balco, 2017; Knudsen et al., 2019).

The cosmogenic nuclide method was initially used to estimate rock surface denudation rates and soon extended to derive catchment-wide denudation rates based on the following assumptions: (a) river sediment is well mixed and representative of the entire catchment, (b) each area of the catchment contributes quartz to the river channel in proportion to its long-term denudation rate, (c) sediment storage within the catchment is negligible, (d) denudation rates are independent of sediment grain size, and (e) denudation is rapid enough that cosmogenic nuclide loss is primarily driven by denudation rather than radioactive decay (Brown et al., 1995; Bierman and Steig, 1996; Granger et al., 1996; von Blanckenburg, 2005; Granger and Riebe, 2014). Several calculators have been developed accordingly, such as CosmoCalc (Vermeesch, 2007), CRONUS-Earth (Balco et al., 2008), CAIRN (Mudd et al., 2016), BASINGA (Charreau et al., 2019), and RIVERSAND (Stübner et al., 2023).

We use the Catchment-Averaged denudatIon Rates from cosmogenic Nuclides (CAIRN), a freely available pixel-based calculator (Mudd et al., 2016), to calculate catchment-wide denudation rates. CAIRN calculates ¹⁰Be production rates for each pixel in a catchment and then uses a temporary denudation rate to obtain pixel-based ¹⁰Be concentrations and their average. CAIRN determines the catchment-wide denudation rates by adjusting this temporary denudation until the averaged ¹⁰Be concentrations match the measurements. CAIRN uses the commonly used Lal/St scaling model (Lal, 1991; Stone, 2000). The inputs to the CAIRN calculator include sample location, ¹⁰Be concentrations, and a digital elevation model (DEM) of the study area. We used a 25 m DEM for the Roda Catchment, downloaded from the geoportal Thuringia (https://geoportal.thueringen.de/gdi-th/download-offene-geodaten/download-hoehendaten, last access: 6 February 2026). The default density of 2.65 g cm⁻³ was used to allow for consistent comparison with most published denudation data. Topographic shielding corrections for catchments were automatically performed by the CAIRN calculator. Corrections for lithology and snow shielding are not applied, as lithology (dominated by siliciclastic sedimentary rocks) and quartz content (> 50 %) are relatively homogeneous in the Roda Catchment, and snow cover is limited in both duration and thickness.

2.4 Local denudation rate calculations

We also use CAIRN to calculate local denudation rates for the 5 soil samples, with the same parameters to ensure consistency. In addition, due to plowing in recent decades, the top ∼ 30 cm of soil is well mixed and has a density of approximately 1.3 g cm⁻³. The plowing depth is equivalent to 14.7 cm of rock with a density of 2.65 g cm⁻³. The sample thickness was therefore set to 14.7 cm. Topographic shielding is negligible for these high, flat sites.

2.5 Global datasets for comparison

To investigate denudation across different spatial and temporal scales, we combined our results with previously published short- and long-term denudation rates for comparison. The Octopus database compiles global ¹⁰Be-derived long-term denudation rates (Codilean et al., 2018, 2022; Codilean and Munack, 2025). As these rates were recalculated using CAIRN, direct comparison and integration with our data are justified. Chen et al. (2022) compiled global short-term erosion rates estimated from suspended sediment fluxes measured at gauging stations. Their Fig. 1 shows the gauging stations used worldwide. Chen et al. (2022) assumed a uniform density of 1.6 g cm⁻³ to convert sediment yields to catchment-averaged erosion rates. For consistency with the ¹⁰Be-derived long-term denudation rates, we used a density of 2.65 g cm⁻³ instead. In addition, as Chen et al. (2022) did not provide catchment polygons, we assigned catchment polygons from the HydroBASINS database (https://www.hydrosheds.org, last access: 6 February 2026) to each gauging station based on station locations and catchment area records in the dataset, using visual inspection in ArcGIS Pro^® with satellite imagery as a basemap. Automated catchment delineation tools in ArcGIS Pro^® were tested but yielded implausible catchment extents for some gauging stations; therefore, a visual assignment approach was adopted. The assigned catchments in Europe are shown in Fig. 5.

Table 1 Sample coordinates and weights, ⁹Be weights, and measured AMS data for ¹⁰Be concentration calculations.

3 Results

AMS measurements show that the ¹⁰Be $/$ ⁹Be ratios for all samples range from 120.2 to 359 × 10⁻¹⁵ (Table 1). The ¹⁰Be $/$ ⁹Be ratios of the three processing blanks are 4.3, 7.3, and 7.7 × 10⁻¹⁵, representing < 6 % of the sample ratios. The blank-corrected ¹⁰Be concentrations range from 54.6 × 10³ to 166.5 × 10³ atoms g⁻¹ (Table 2). The derived catchment-wide denudation rates range from 23.8 ± 5.4 to 79 ± 18 mm kyr⁻¹ (Fig. 3 and Table 2) with an uncertainty-weighted mean denudation rate of 59.3 ± 2.8 mm kyr⁻¹. Sample Roda4 (23.8 ± 5.4 mm kyr⁻¹) indicates a much lower denudation rate than others (Fig. 3c). If this sample is omitted, the weighted mean denudation rate is 61.6 ± 2.0 mm kyr⁻¹. Local denudation rates are generally lower, ranging from 23.4 ± 5.6 to 41.9 ± 9.8 mm kyr⁻¹ with a weighted mean value of 33.5 ± 3.2 mm kyr⁻¹ (Fig. 3c).

Table 2 Sample name and associated catchment characteristics (mean altitude, area, and mean slope), measured ¹⁰Be concentrations (blank-corrected), and derived denudation rates.

Figure 4 (a) Correlation between slope and catchment-wide denudation rates. (b) Correlation between latitude and denudation rates. (c) Cumulative distribution function (CDF) curves showing denudation rates in Europe and worldwide. Sample Roda4 is excluded from these plots because of its anomalously low denudation rate (see Fig. 3c). All subplots are based on the same dataset taken from the Octopus database (Codilean et al., 2018, 2022; Codilean and Munack, 2025).

4 Discussion

4.1 Uncertainty analysis

Before comparing our results with published denudation rates, we briefly discuss several potentially confounding factors.

First, chemical weathering occurs throughout soil, regolith, and bedrock and contributes to denudation rates. However, ¹⁰Be concentrations are mainly sensitive to near-surface mass removal (Dixon et al., 2009; Ott et al., 2022). This leads to a systematic underestimation of denudation rates. The Roda Catchment is dominated by weathering-resistant siliciclastic sedimentary rocks. Therefore, the chemical weathering effect is likely limited.

Second, catchment-wide denudation rates can be biased by sediment storage and remobilization. Ideally, river sediments at catchment outlets originate from the entire catchment, and the required time for sediment transportation is negligible compared to the time for denudation on hillslopes (e.g., von Blanckenburg, 2005; Granger and Riebe, 2014; Dosseto and Schaller, 2016). In the Roda Catchment, no vast terraces or floodplains exist. The catchment is small, and sediment transport distance is short (Fig. 1). Therefore, sediment storage and remobilization are minimal.

Third, farming may locally elevate denudation rates above long-term averages and bias catchment-wide denudation rates toward human-influenced subareas (Granger et al., 1996). This effect is likely small in the Roda Catchment because slope, the primary control on erosion, is similar between farmland (6°) and non-farmland areas (8°), and other factors, such as lithology, precipitation, and vegetation cover, are consistent across the catchment.

Fourth, other human activities, such as construction work, can disturb ¹⁰Be signals. The anomalously low denudation rate derived from sample Roda4 (Fig. 3c) may be related to extensive urban development along the upstream river reach. As illustrated in Fig. 2f, the river channel is largely modified by humanmade stone revetment constructed from abundant allochthonous lithic materials. KMZ files in the Supplement allow further inspection of anthropogenic disturbances within this catchment using Google Earth.

4.2 Comparison of denudation rates in Europe and globally

The catchment-wide denudation rates in the Roda Catchment fall within the range of existing European data (Fig. 4a). Denudation rates from the Roda Catchment, Europe, and around the globe show similar slope dependence (Fig. 4a). Global data, including European records, are sourced from the Octopus database. European data represent denudation rates in relatively high latitude (Fig. 4b). The cumulative distribution function (CDF) plot indicates that denudation rates in Europe are much higher than global rates, with a CDF 0.5 value > 40 mm kyr⁻¹ and thus more than twice the global value (Fig. 4c).

The European data range from 30 to 65 mm kyr⁻¹, representing the 25th and 75th percentiles, respectively. These rates integrate averaging timescales of approximately 9 to 20 ka (von Blanckenburg, 2005), extending back into the last glacial period. During this time period, Europe experienced widespread glaciation and extensive periglacial processes, including cryoturbation and solifluction (Isarin and Renssen, 1999; Eissmann, 2002). Syntheses of European periglacial geomorphology indicate that frost-related processes extended far beyond glacier margins, affecting large ice-free lowland areas of northern and central Europe (e.g., Oliva et al., 2022). Palaeopermafrost reconstructions further demonstrate that periglacial conditions were widespread across large parts of western and central Europe during the Last Glacial Maximum (e.g., Vandenberghe and Pissart, 1993). Consistent with geomorphological and palaeopermafrost evidence, the widespread cover-bed sequences on slopes between 37 and 56° N indicate that periglacial processes once affected large parts of the European continent during the Quaternary (Kleber, 1997). The periglacial processes may have altered landscape erodibility and potentially increased denudation rates across Europe (Schaller et al., 2001; Delunel et al., 2010; Roda-Boluda et al., 2023). Therefore, the generally higher denudation rates from Europe are probably due to past glacial and periglacial dynamics.

Figure 5 Catchments with long-term denudation (Octopus data, Codilean et al., 2018) or short-term erosion rates (Chen et al., 2022) in central Europe.

4.3 Comparison of long-term denudation and short-term erosion rates in Europe

We compare ¹⁰Be-derived long-term denudation rates with gauged short-term erosion rates in Europe (Fig. 5) to investigate denudation on different timescales. Results show that long-term denudation rates are positively correlated with slope (Fig. 6a). The short-term erosion rates display greater variability than the long-term denudation rates (Fig. 6a). This likely documents human activities, such as deforestation, farming, mining, and quarrying (Ferrier et al., 2005). Those activities are more stochastic compared to natural denudation drivers, such as topographic gradient and precipitation. As a result, human activity may lead to great variability in short-term erosion rates and a weaker correlation between slope and erosion rates (Fig. 6a). The variability decreases for slopes > 20°, probably because human activities are relatively weak in steep regions.

Figure 6 (a) Correlation between slope and long-term denudation rates (blue) and short-term erosion rates (orange) in Europe. (b) CDF curves for both long-term denudation rates and short-term erosion rates. The red dashed horizontal line indicates that the CDF 0.5 value increases significantly from ∼ 50 to > 200 mm kyr⁻¹. The data correspond to the catchments shown in Fig. 5.

The CDF plot indicates that ¹⁰Be-derived long-term denudation rates are generally higher than the short-term erosion rates in Europe (Fig. 6b). This observation is consistent with Chen et al. (2022). Many factors can lead to this pattern. The first reason is the difference between gauged erosion rates and ¹⁰Be-derived denudation rates. Denudation rates derived from cosmogenic nuclides represent the total mass loss by physical removal of particles and chemical removal of solutes (von Blanckenburg, 2005; Granger and Riebe, 2014). The gauged measurements used account for only suspended sediment flux and miss the dissolved mass loss. Studies have shown that chemical weathering can even dominate denudation rates in limestone or carbonate settings (e.g., Ott et al., 2023; Schaller et al., 2025).

However, chemical weathering may not be the only or main reason for this pattern (Fig. 6b). ¹⁰Be-derived long-term denudation rates average over timescales of thousands of years, while gauged measurements cover only decades and usually cannot capture rare extreme heavy floods (Kirchner et al., 2001; Schaller et al., 2001; Meyer et al., 2010a; Granger and Riebe, 2014).

Moreover, land-cover changes in Europe over the last several thousand years need to be considered. Reconstructions of land-cover change show that Europe experienced extensive forest clearance during the Roman and Medieval periods, reflecting agricultural expansion and the exploitation of forests for fuel wood and construction materials (Kaplan et al., 2009). This deforestation has been widely linked to enhanced hillslope erosion and increased sediment fluxes recorded in fluvial and lacustrine archives across Europe (Dotterweich, 2008, 2012). A synthesis of global erosion-rate data further indicates that human activities can accelerate natural erosion rates by a factor of ∼ 2–3 under moderate land use and by up to an order of magnitude under intensive land use (Saunders and Young, 1983). Together with the geomorphic legacy of periglacial processes during the last glacial period, widespread anthropogenic disturbances may have also contributed to long-term denudation rates exceeding short-term erosion rates (Fig. 6b).

4.4 Topographic relief changes in the Roda Catchment

In the Roda Catchment, we constrained both catchment-wide and local denudation rates on catchment divides. The mean catchment-wide denudation rate is ∼ 62 mm kyr⁻¹ (if we treat sample Roda4 as an outlier), which is much higher than the mean local denudation rate of ∼ 34 mm kyr⁻¹. The averaging timescales are about 10 and 18 kyr, respectively, so we can assess changes in topographic relief since then. At face value, the average surface lowering rate in the catchment area exceeds that at the catchment divides by 28 mm kyr⁻¹.

However, a relatively thick soil layer has been observed at the catchment divides. Assuming that all eroded material was soil with a density of 1.3 g cm⁻³, this would result in a mean denudation rate of 69 mm kyr⁻¹, rather than 34 mm kyr⁻¹. Consequently, the results indicate that denudation may have contributed to relief changes in the Roda Catchment, ranging from ∼ 0 to 28 mm kyr⁻¹. This relief change is broadly consistent with the observations in the Harz Mountain (5–10 mm kyr⁻¹) (Hetzel et al., 2024) and the Black Forest (24 mm kyr⁻¹) in Germany (Meyer et al., 2010b).

5 Conclusions

This paper presents ¹⁰Be-derived catchment-wide and local denudation rates for the Roda Catchment in central Germany. The derived denudation rates indicate that the Roda Catchment erodes at a mean rate of ∼ 62 mm kyr⁻¹, which is much higher than the mean denudation rate of 34 mm kyr⁻¹ observed at the catchment divides. In combination with published long-term denudation rates and short-term erosion rates, we explored the roles of periglacial conditions and anthropogenic disturbance in driving denudation and landscape evolution. We argue that the generally high long-term denudation rates in Europe are likely due to periglacial processes during the last glacial period and the massive forest clearance during Roman and Medieval times. These factors can also help explain why long-term denudation rates exceed short-term erosion rates observed in Europe. Moreover, rare but extreme events are likely important for long-term denudation. Denudation has resulted in an average topographic relief change of 0 to 28 mm kyr⁻¹ in the Roda Catchment over the past 10 ka.

Appendix A: Preparation of our ⁹Be carrier solution from a phenakite crystal

We prepared our Be carrier from a phenakite crystal from Kragerö, Norway, which was kindly provided by the Geosciences Collections, TU Bergakademie Freiberg. The procedure follows that of Merchel et al. (2013):

1. Grinding, dissolution, and dryness. We ground the phenakite crystal and then treated the phenakite powder with HF (48 %) and a small amount of HNO₃ (70 %) in a high-density polyethylene bottle. The bottle was placed at room temperature in an ultrasonic bath during the day and on a shaker table at night. A few days later, over 80 % of the material was dissolved, and the decanted solution was evaporated to dryness.

2. Be purification by fuming. We treated the evaporated solution remains with warm water for several hours (Stone, 1998) and centrifuged the solution to remove insoluble compounds. The solution was then evaporated to dryness and treated with HF (48 %) three times to fume off boron trifluoride (BF₃), which was followed by addition and evaporation of HClO₄ (70 %) to destroy all remaining fluorides. The residue was then dissolved in HCl (7.1 mol L⁻¹).

3. Be purification by precipitation. We gradually added NH₃aq (32 %) to the HCl solution until pH 4 was reached, and the generated hydroxides (e.g., Ti(OH)₂, Fe(OH)₃) were separated from the solution by centrifugation. Further addition of NH₃aq (32 %) precipitated beryllium hydroxide, which was washed three times with dilute NH₃aq (pH 8–9) and then redissolved in HCl (18 %), obtaining the Be carrier solution.

4. Concentration measurements. We measured the concentration of the Be carrier in three laboratories using either inductively coupled plasma optical emission spectrometry (ICP-OES) or inductively coupled plasma mass spectrometry (ICP-MS). Calibration was done against various dilutions of a commercial Be standard (LGC Standards). Table A1 presents all measurement results. The density (1.0259 ± 0.0017 g mL⁻¹) was determined by comparing measured ⁹Be carrier mass to that of a deionized water sample (assumed to be 1.0 g mL⁻¹), using equal volumes for both across five replicates. This allows the calculation of the ⁹Be concentration from 3511 ± 52 mg L⁻¹ (Table A1) to 3422 ± 51 mg kg⁻¹. The uncertainty is derived from the standard error of the mean of both water and the ⁹Be carrier, and it is small (1 order of magnitude lower than the one from the ICP) compared to the overall uncertainty.

Table A1 Concentration of Be carrier measured in different laboratories.