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Cosmogenic 10^Be and 26^Al concentrations in fluvial sediments from the Mohand Range in the northwestern Himalaya

Because of the multi-stepped pathways of sediment comprising the foreland fold-thrust belt (FFTB), detrital quartz grains that recycle from the FFTB sources contain cosmogenic radionuclides (CRN), such as 10^Be and 26^Al, accumulated during previous exposure, resulting in inheritance and, hence, anomalously low erosion rates. This inhibits the straightforward use of 10^Be as tracers for modern erosion rates and sediment discharge from the FFTB, prevalent at the external edges of collisional orogens such as the Himalaya. We present a novel approach for quantifying the erosion rates of FFTB by comparing measured and modeled CRN concentrations in fluvial sediments. We apply this approach to the Mohand Range, an emergent fault-related fold in the frontal part of the northwestern Himalaya (see the location map below). The 10^Be and 26^Al datasets presented here were used to calibrate our model, which we used to quantify the erosion rates in and sediment flux from the Mohand Range. Datasets provided here include a summary of the location and depositional age of 33 fluvial sediments and two sandstone samples collected from the Mohand Range, 10^Be analysis results of 23 of these fluvial sediments and two bedrock samples, and 26^Al-10^Be pair analysis results of the remaining ten fluvial sediment samples (Dataset S1). Moreover, the data include the depositional age map of uplifted older foreland sediments across the western Mohand Range (Dataset 2) and the map of best-fit 10^Be concentration inherited from Himalayan paleoerosion (Dataset 3) and sediment burial in the foreland (Dataset 4). We also include a map of the best-fit 10^Be concentration produced during modern erosion of the Mohand Range (Dataset 5) and a map of the best-fit uplift/erosion rates across the western Mohand Range (Dataset 6). For more information (e.g., sampling method, analytical procedure, and data processing), please refer to the main article (Mandal et al., 2023).

Geochemical data on silicon isotope and Ge/Si ratios along a global erodosequence

We provide geochemical data for three sites that define a gradient of erosion rates – an “erodosequence”. These sites are the Swiss Central Alps, a rapidly-eroding post-glacial mountain belt; the Southern Sierra Nevada, USA, eroding at moderate rates; and the slowly-eroding tropical Highlands of central Sri Lanka. Specifically, we provide silicon isotope ratios and germanium/silicon ratios and the major element composition of 1) rock, 2) saprolite, 3) soil, 4) plants, 5) river dissolved loads, 6) the soil and saprolite amorphous silica fraction (accessed with a NaOH leach), and 7) the soil and saprolite clay-size fraction (isolated with a differential settling protocol). These data serve two purposes. First, they allow us to improve understanding of the controls on silicon isotopes and germanium/silicon ratios in the 'Critical Zone'. Specifically, we can quantify the fractionation factors (for silicon isotopes) and the exchange coefficients (for germanium/silicon ratios), for secondary mineral precipitation and for biological uptake. Secondly, we can use mass-balance approaches to quantify the partitioning of silicon - a nutrient, and a major rock-forming element - among secondary minerals, plant material, and solutes. All samples are assigned with International Geo Sample Numbers (IGSN), a globally unique and persistent Identifier for physical samples. The IGSNs are provided in the data tables and link to a comprehensive sample description.

Denudation and weathering rates of carbonate landscapes from meteoric 10Be/9Be ratios

We provide sample information and geochemical data for obtaining erosion, weathering, and denudation rates from a framework based cosmogenic meteoric 10Be versus stable 9Be (10Be/9Be) ratios. We modified this published silicate framework (von Blanckenburg et al., 2012) to carbonate landscapes, and performed thorough ground-truthing and testing of assumptions, as this is the first application of the framework for carbonate lithologies. The most important methodological findings are as follows: 1) We amended a sequential extraction step specific for solubilizing total carbonate-bound Be using acetic acid. As this extraction cannot distinguish between secondary and primary carbonate, we employed carbon stable isotopes to obtain the fraction of Be associated with secondary carbonate. We find that >90% of total carbonate-bound Be is bound to secondary carbonate, meaning that distinguishing between secondary and primary carbonate and employing carbon stable isotopes may not be necessary. 2) Using radiogenic strontium isotope ratios we found that about a third of the 9Be contained in secondary carbonate is derived from the dissolution of silicate phases, likely clastic impurities such as clays. These silicate phases also adsorb meteoric 10Be during weathering. The method is thus applicable to pure limestone as well as mixed carbonate-siliciclastic lithologies. 3) Total 9Be concentrations in bedrock are heterogeneous in the Jura, and are potentially controlled by the amount of silicate impurities contained in limestone. Yet the average 9Beparent in summed carbonate- and silicate-bound fractions (0.07 ug/g) is about 9 times lower than values from existing rock databases. In limestones studies, 9Beparent must be thus determined case-by-case on local bedrock. 4) The analysis of partition coefficients Kd for 10Be and 9Be, respectively, and very similar 10Be/9Be ratios show that dissolved Be has equilibrated between reactive (amorphous and crystalline Fe-oxides) and secondary carbonate phases. Secondary carbonate phases are thus part of the reactive Be pool in limestone settings. 5) As in previous studies in silicate lithologies 10Be and 9Be concentrations show pronounced differences between soil and sediment samples that we attribute to grain size dependence and sorting. The 10Be/9Be ratios however cover a remarkably narrow range for all samples, resulting a in narrow range in denudation rates. 6) The fraction of 9Be released by weathering and partitioned into the secondary reactive or dissolved phase serves as a Be-specific proxy for the degree of weathering. 7) The atmospheric depositional flux of 10Be estimated for the Jura mountains from concentrations of dissolved and particulate 10Be and river gauging is about 80% of estimates from independent global GCM-based distribution maps. The GCM estimates thus provide sufficient accuracy. From application of these new principles, weathering and erosion in the French Jura Mountains can be described as follows: The proportion of weathering in total denudation W/D is >0.9, due to the high purity of the limestone that almost completely dissolved except for a small silicate mineral fraction that, however, carries 50% of the bedrock’s 9Be. Resulting 10Be/9Be-derived denudation rates are on average 300 t/km2/yr for soils and 580 t/km2/yr for river sediments. The soil-derived values agree well with previous estimates from gauging data despite their entirely different (decadal vs. millennial) integration time scales. That sediment-derived denudation rates exceed those from soil we attribute to a 30-60% contribution from subsurface bedrock weathering. On a global scale, our data provides the first cosmogenic-based denudation rates for the precipitation (MAP) range of 1200 to 1700 mm/yr under a temperate climate and dense vegetation cover. Previous millennial-scale denudation rates from in situ-36Cl in calcite from less vegetated sites do not exceed 250 t/km2/yr in this precipitation range. With 500-600 t/km2/yr our denudation rates peak at MAP of 1200-1300 mm/yr, and then show a trend of decreasing D with increasing MAP.

Laboratory and field data used to determine the controls of drainage density differences in two granitoid plutons in semi-arid Central Chile

Here we provide in situ 10Be data, meteoric 10Be data, X-Ray fluorescence data, infiltration rate field date, chemical extraction data, a summary of grain size data, all grain size data (Table S7), mineral point counting data, XRD data, soil grain size data, and data from laboratory measurements of hydrological parameters. Field work in Santa Gracia was conducted in February of the years 2019 and 2020 and laboratory work was conducted between 2019 and 2023. This data publication accompanies our study (Lodes et al., 2024), in which we investigate whether lithology controls drainage density in Santa Gracia, a semi-arid field site in Central Chile. In the study, we compare the density of drainages in two distinct, neighbouring landscapes underlain by a monzogranite and two diorite plutons (which we refer to as the “inner diorite” and the “outer diorite”). We collected multiple datasets to understand the underlying mechanisms behind the drainage density differences. The data was collected as part of the German Science Foundation (DFG) priority research program SPP-1803 “EarthShape: Earth Surface Shaping by Biota” (grant SCHE 1676/4-1 and -2 to D. S.; funding of P. G. through grant BE 1780/53-1 and -2).

Analysis of cosmogenic 10Be concentrations of Siwalik sediments and modern river sands from the north-western Himalaya and the calculated 10Be-derived paleoerosion rates

These datasets were used to evaluate the main controls on last ~6 million years erosion rate variability of the northwestern Himalaya. The Earth’s climate has been cooling during the last ~15 million years and started fluctuating between cold and warm periods since ~2-3 million years ago. Many researchers think that these long-term climatic changes were accompanied by changes in continental erosion. However, quantifying erosion rates in the geological past is challenging, and previous studies reached contrasting conclusions. In this study, we quantified erosion rates in the north-western Indian Himalaya over the past 6 million years by measuring in situ-produced cosmogenic 10Be in exhumed older foreland basin sediments. The 10Be is produced by cosmic rays in minerals at the Earth's surface, and its abundance indicates erosion rates. Our reconstructed erosion rates show a quasi-cyclic pattern with a periodicity of ~1 million year and a gradual increase towards the present. We suggest that both patterns—cyclicity and gradual increase—are unrelated to climatic changes. Instead, we propose that the growth of the Himalaya by repeatedly scraping off rocks from the Indian plate (basal accretion), resulted in changes of its topography that were accompanied by changes in erosion rates. In this scenario, basal accretion episodically changes rock-uplift patterns, which brings landscapes out of equilibrium and results in quasi-cyclic variations in erosion rates. We used numerical landscape evolution simulations to demonstrate that this hypothesis is physically plausible. Datasets provided here includes summary of the location, depositional age, and stratigraphic position of 41 Siwalik sandstone samples collected from the Haripur section in Himachal Pradesh, India (Dataset S1); 10Be analysis results of Siwalik samples (2021-006_Mandal-et-al_Dataset-S1); sample location and 10Be analysis results of modern river sands from the Yamuna River and its tributaries near the Dehradun Basin (2021-006_Mandal-et-al_Dataset-S2); input parameters for the calculation of paleoerosion rates (2021-006_Mandal-et-al_Dataset-S3); and reconstructed 10Be paleoconcentrations and paleoerosion rates (Dataset S4). Moreover, the data include a compilation of published magnetostratigraphy-derived sediment accumulation rates in the late Cenozoic Himalayan foreland basin (2021-006_Mandal-et-al_Dataset-S5). We also include a movie (2021-006_Mandal-et-al_Movie-S1) that is a complete numerical landscape evolution model run with four consecutive accretion cycles of equal magnitude. For more information (for e.g., sampling method, analytical procedure, and data processing) please refer to the associated data description file and the main article (Mandal et al., 2021).

Medial moraine cosmogenic 10Be data and glacier surface velocities from four Swiss valley glaciers around Pigne d’Arolla

At valley glaciers, rockwall erosion supplies debris to glacier surfaces. Once deposited on the ice, rockwall debris is passively entrained and becomes part of the glacial system, e.g., forming medial moraines as downglacier transport continues. Where debris occurs supraglacial, it modifies ice ablation and, thus, changes in rockwall erosion and debris supply rates modify glacial debris cover and mass balance and may affect glacier retreat in response to climate change. Yet, estimates on rockwall erosion rates close to glacier surfaces are few and quantifying spatiotemporal supply patterns is not trivial. This data publication is supplementary to the study on rockwall erosion rates at five Swiss valley glaciers around Pigne d’Arolla, by Wetterauer & Scherler (2023). We temporally and spatially assess rockwall erosion by measuring in situ-produced cosmogenic 10Be concentrations ('[10Be]measured') in medial moraine debris, which we systematically sampled along downglacier-profiles, and by comparing records from various medial moraines, which are supplied by rockwalls differing in exposure and morphology. However, as '[10Be]measured' within supraglacial debris is the sum of '[10Be]rockwall', accumulated during rockwall erosion, and '[10Be]transport', accumulated during post-depositional downglacier transport, medial moraine '[10Be]measured' should be corrected for '[10Be]transport'. If glacier velocities through time are known, '[10Be]transport' can be estimated by downglacier debris trajectory modelling. Providing our 10Be dataset and ~40-year records of glacier surface velocities from four of the five valley glaciers (Glacier du Brenay, Glacier de Cheilon, Glacier de Pièce, Glacier de Tsijiore Nouve) is the main objective of this data publication. The dataset of the fifth glacier (Glacier d’Otemma) has already been published as case study by Wetterauer et al. (2022a,b).

A global database of radiogenic Nd and Sr isotopes in marine and terrestrial samples (V. 3.0)

The database presented here contains radiogenic neodymium and strontium isotope ratios measured on both terrestrial and marine sediments. It was compiled to help assessing sediment provenance and transport processes for various time intervals. This can be achieved by either mapping sediment isotopic signature and/or fingerprinting source areas using statistical tools (e.g. Blanchet, 2018b, 2018a). The database has been built by incorporating data from the literature and various databases and data compilations, and harmonizing the metadata, especially units and geographical coordinates. The original data were processed in three steps. Firstly, a specific attention has been devoted to provide geographical coordinates to each sample in order to be able to map the data. When available, the original geographical coordinates from the reference (generally DMS coordinates, with different precision standard) were transferred into the decimal degrees system. When coordinates were not provided, an approximate location was derived from available information in the original publication. Secondly, all samples were assigned a set of standardized criteria that help splitting the dataset in specific categories. We defined categories associated with the sample location, the type of sample, the sedimentary fraction measured, or the deposition age (as given in the original publication). This dataset consists of one spreadsheet: "Dataset_Nd_Sr_isotopes_V3.txt", which contains the assembled dataset of marine and terrestrial Nd and/or Sr concentration and isotopes, together with sorting criteria and geographical locations. A full reference list is provided in the file “References_Database_Nd_Sr_isotopes_V3.pdf”. R code for mapping the data and running statistical analyses is also available for this dataset (Blanchet, 2018b, 2018a).

Geochemical data on rock weathering along an erodosequence

We provide geochemical background data on the partitioning and cycling of elements between rock, saprolite, soil, plants, and river dissolved and solid loads from at three sites along a global transect of mountain landscapes that differ in erosion rates – an “erodosequence”. These sites are the Swiss Central Alps, a rapidly-eroding post-glacial mountain belt; the Southern Sierra Nevada, USA, eroding at moderate rates; and the slowly-eroding tropical Highlands of Sri Lanka. The backbone of this analysis is an extensive data set of rock, saprolite, soil, water, and plant geochemical data. This set of elemental concentrations is converted into process rates by using regolith production and weathering rates from cosmogenic nuclides, and estimates of biomass growth. Combined, they allow us to derive elemental fluxes through regolith and vegetation. The main findings are: 1) the rates of weathering are set locally in regolith, and not by the rate at which entire landscapes erode; 2) the degree of weathering is mainly controlled by regolith thickness. This results in supply-limited weathering in Sri Lanka where weathering runs to completion, and kinetically-limited weathering in the Alps and Sierra Nevada where soluble primary minerals persist; 3) these weathering characteristics are reflected in the sites’ ecosystem processes, namely in that nutritive elements are intensely recycled in the supply-limited setting, and directly taken up from soil and rock in the kinetically settings; 4) contrary to common paradigms, the weathering rates are not controlled by biomass growth; 5) at all sites we find a deficit in river solute export when compared to solute production in regolith, the extent of which differs between elements but not between erosion rates. Plant uptake followed by litter erosion might explain this deficit for biologically utilized elements of high solubility, and rare, high-discharge flushing events for colloidal-bound elements of low solubility. Our data and the new metrics have begun to serve for calibrating metal isotope systems in the weathering zone, the isotope ratios of which depend on the flux partitioning between the compartments of the Critical Zone. We demonstrate this application in several isotope geochemical companion papers with associated datasets from the same samples. All samples are assigned with International Geo Sample Numbers (IGSN), a globally unique and persistent Identifier for physical samples. The IGSNs are provided in the data tables and link to a comprehensive sample description in the internet.

Sediment geochemistry data for the publication: “10Be/9Be ratios reveal marine authigenic clay formation”

As reverse weathering has been shown to impact long-term changes in atmospheric CO2 levels, it is crucial to develop quantitative tools to reconstruct marine authigenic clay formation. We explored the potential of the beryllium (Be) isotope ratio (10Be/9Be) recorded in marine clay-sized sediment to track neoformation of authigenic clays. The power of such proxy relies on the orders-of-magnitude difference in 10Be/9Be ratios between continental Be and Be dissolved in seawater. On riverine and marine sediments collected along a Chilean margin transect we chemically extracted reactive phases and separated the clay-sized sediment fraction. We compare the riverine and marine 10Be/9Be ratio of this fraction. Moreover, we compare the elemental and mineralogical composition and the Nd and Sr-isotopic composition of these samples. 10Be/9Be ratios increase four-fold from riverine to marine sediment. We attribute this increase to the incorporation of Be high in 10Be/9Be from dissolved biogenic opal, which also serves as a Si-source for the precipitation of marine authigenic clays. 10Be/9Be ratios thus sensitively track reverse-weathering reactions forming marine authigenic clays.

Sample and Modelling Data for Cosmogenic 10Be in Medial Moraine Debris of Glacier d’Otemma, Switzerland

This data publication is supplementary to the study on headwall erosion rates at Glacier d'Otemma in Switzerland, by Wetterauer et al. (2022). Debris on glacier surfaces stems from steep bedrock hillslopes that tower above the ice, so-called headwalls. Recently, rock walls in high-alpine glacial environments experience increased destabilization due to climate warming. Since supraglacial debris alters the melt behaviour of the ice underneath, increased headwall erosion and debris delivery to glacier surfaces will modify glacial mass balances. Therefore, we expect that the response of glaciers to climate change is likely linked to how headwall erosion responds to climate change. As headwall debris is deposited on the ice surface of valley glaciers it is passively transported downglacier, both supra- and englacially. Where two glaciers join, debris along their margins is merged to form medial moraines. Since medial moraine debris tends to be older downglacier, systematic downglacier-sampling of medial moraine debris and the measurement of in situ-produced cosmogenic 10Be concentrations ([10Be]) hold the potential to assess long-term (>10^2-10^4 yrs) headwall erosion rates through time. However, to obtain the cosmogenic signals of headwall erosion, [10Be] within supraglacial debris need to be corrected for glacial transport time, as cosmogenic nuclides continue to accumulate during exposure and transport. This additional 10Be accumulation during debris transport can be accounted for by simple downglacier debris trajectory modelling. Providing our 10Be dataset together with detailed information on our 1-D modelling approach is the main objective of this data publication. The data is presented as one single xlsx-file with three different tables. A detailed description of the sample processing and the debris trajectory model are provided in the data description file of this data publication. For more information see our study Wetterauer et al. (2022).

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