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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.
Sampling large river´s sediment at outlets for cosmogenic nuclide analysis yields mean denudation rates of the sediment producing areas that average local variations in denudation commonly found in small rivers. Using this approach, we measured in situ cosmogenic 26Al and 10Be concentrations in sands of >50 large rivers over a range of climatic and tectonic regimes covering 32% of Earth’s terrestrial surface.River samples were processed in the Helmholtz Laboratory for the Geochemistry of the Earth Surface (HELGES) (von Blanckenburg et al., 2016). 10Be/9Be ratios were measured by Accelerator Mass Spectrometry (AMS) at the University of Cologne and normalized to the KN01-6-2 and KN01-5-3 standards. Denudation rates were calculated using a time-dependent scaling scheme according to Lal/Stone ”Lm” scaling (see Balco et al., 2008) together with a sea level high latitude (SLHL) production rate of 4.13 at/(gxyr) as reported by Martin et al. (2017).Measured in the mineral quartz, the cosmogenic nuclides 26Al and 10Be provide information on how fast Earth´s surface is lowering through denudation. If sediment is however stored in catchments over time spans similar to the nuclides half-lives (being 0.7 Myr and 1.4 Myr for 26Al and 10Be, respectively), the nuclide´s budget is disturbed, and meaningful denudation rates cannot be calculated. The ratio of 26Al/10Be informs us about these disturbances. In 35% of analyzed rivers, we find 26Al/10Be ratios significantly lower than these nuclides´ surface production rate ratio of 6.75 in quartz, indicating sediment storage and burial exceeding 0.5 Myr. We invoke mainly a combination of slow erosion, long transport, and low runoff for these low ratios.In the other 65% of rivers we find 26Al/10Be ratios within uncertainty of their surface production-rate ratio, indicating cosmogenic steady state, and hence meaningful denudation rates can be calculated. For these rivers, we derive a global source-area denudation rate of 140 t/km^2/yr that translates to a flux of 3.10 Gt/yr. By assuming that this sub-dataset is geomorphically representative of the global land surface, we upscale this value to the total surface area for exorheic basins, thereby obtaining a global denudation flux from cosmogenic nuclides of 15.1 Gt/yr that integrates over the past 5 kyr.In Table S1, we provide detailed 10Be nuclide production rates and their correction due to ice shielding and carbonates that are necessary to calculate denudation rates. We provide International GeoSample Numbers (ISGN) for samples used in the analysis, except values that were compiled from published sources. We then compare these denudation rates, converted to sediment fluxes, to published values of sediment fluxes from river load gauging. We find that our cosmogenic nuclide-derived sediment flux value is similar, within uncertainty, to published values from cosmogenic nuclides from small river basins (23 Gt/yr) upscaled using a global slope model, and modern sediment and dissolved loads exported to the oceans (23.6 Gt/yr). In Table S3, we compiled these modern sediment loads and give their references. We also compiled runoff values (mm/yr) from published sources (Table S2) that are used to infer what controls denudation rates.For more details on the sampling and analytical methods, please consult the data description part of this publication.
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.
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 the SedDB database 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 ("Region", "Sub-region", "Location", which relate to location at continental to city/river scale) or with the sample types (terrestrial samples – “aerosols”, “soil sediments”, “river sediments”, “rocks” - or marine samples –“marine sediment” or “trap sample”). Thirdly, samples were discriminated according to their deposition age, which allowed to compute average values for specific time intervals (see attached table "Age_determination_Sediment_Cores_V2.txt"). A first version of the database was published in September 2018 and presented data for the African sector. A second version was published in April 2019, in which the dataset has been extended to reach a global extent. The dataset will be further updated bi-annually to increase the geographical resolution and/or add other type of samples.This dataset consists of two tab separated tables: "Dataset_Nd_Sr_isotopes_V2.txt" and "Age_determination_Sediment_Cores_V2.txt". "Dataset_Nd_Sr_isotopes_V2.txt" contains the assembled dataset of marine and terrestrial Nd and/or Sr concentration and isotopes, together with sorting criteria and geographical locations. "Age_determination_Sediment_Cores_V2.txt" contains all background information concerning the determination of the isotopic signature of specific time intervals (depth interval, number of samples, mean and standard deviation). Column headers are explained in respective metadata comma-separated files. A full reference list is provided in the file “References_Database_Nd_Sr_isotopes_V2.rtf”. Finally, R code for mapping the data and running statistical analyses is also available for this dataset (Blanchet, 2018b, 2018a).
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 (see supplemental references).The database has been built by incorporating data from the literature and the SedDB database 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 ("Region", "Sub-region", "Location", which relate to location at continental to city/river scale) or with the sample types (terrestrial samples – “aerosols”, “soil sediments”, “river sediments” - or marine samples –“marine sediment” or “trap sample”). Thirdly, samples were discriminated according to their deposition age, which allowed to compute average values for specific time intervals (see attached table "Age_determination_Sediment_Cores.csv"). The dataset will be updated bi-annually and might be extended to reach a global geographical extent and/or add other type of samples.This dataset contains two csv tables: "Dataset_Nd_Sr_isotopes.csv" and "Age_determination_Sediment_Cores.csv". "Dataset_Nd_Sr_isotopes.csv" contains the assembled dataset of marine and terrestrial Nd and/or Sr concentration and isotopes, together with sorting criteria and geographical locations. "Age_determination_Sediment_Cores.csv" contains all background information concerning the determination of the isotopic signature of specific time intervals (depth interval, number of samples, mean and standard deviation). Column headers are explained in respective metadata comma-separated files. A human readable data description is provided in portable document format, as well. Finally, R code for mapping the data and running statistical analyses is also available for this dataset (see supplemental references).
The western Eger Rift in the Czech Republic is a currently inactive volcanic area characterized by earthquake swarms and degassing of mantle-derived fluids. Gases obtained from minerals and from repeatedly sampled free gases are used to trace the origin and evolution of volatiles and determine the conditions of the magma reservoir. Helium isotopes in fluids and minerals are up to 5.95 RA, with 20Ne/22Ne ratios up to ~11.0 and 21Ne/22Ne ratios up to ~0.048, suggesting a mixed atmospheric-mantle source for neon. Some crustal input may also be present. The slightly lower-than-mantle He isotopic ratios and the variability in Ne isotopic compositions indicate that these gases may have been impacted by a subduction-related crustal component during the Variscan (or Hercynian) Orogeny. 40Ar/36Ar ratios are higher than atmospheric levels and arrive up to 4680, indicating a mixture of atmospheric and mantle sources. Thermobarometry of pyroxene mineral grains reveals temperatures and pressures suggesting that the crystallization started at ~75 km depth and ended at ~20 km depth following a smooth p-T course. This implies diverse magma ascent conditions. A total of 56 gas samples were collected from two intensively degassing areas in the western Eger Rift (Czech Republic), namely the mofette fields of Bublák and Hartoušov. From the Hartoušov mofette field, 24 gas samples of fluids ascending in two boreholes (F1:∼28 m depth and F2: ∼108 m depth) and 22 samples of gases emerging in two nearby ponds [surface expressions Hartoušov Mofette (HM) and Hartoušov Mofette South (HMS)] were taken. Ten samples were collected from a pond in the Bublák mofette field (Bbl). In addition to the gas samples, ten rock samples were collected from rock exposures [i.e. Libá (LI) and Číhaná (CI) in quarries, Horní Slavkov (HS1&2), Pila (PI), Dolní Dražov (DD), Kadaň (KN), Horní Paseky (HP), and Slapany (SL) in natural cliffs, and Hlinky (HL) in an outcrop] within the western Eger rift area. In addition, six samples of ultramafic nodules/xenoliths were obtained from the Quaternary tephra deposit of the Mýtina maar and from Železná hůrka scoria cone. Gas and rock sampling:
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).
This dataset is a continuously growing collection of lead isotope reference data. Lead isotopes are an established method to reconstruct the raw material provenance of archaeological objects. They are typically applied to artefacts made of copper, lead, silver, and their alloys. However, also the raw material provenance of other materials such as glass, pigments and pottery was already investigated using lead isotopes. To successfully reconstruct the origin of the raw material, lead isotope signatures from as many as possible suitable raw material occurrences must be known. In the past, large-scaled research projects were carried out to characterise ore deposits especially in the Mediterranean area and Western Europe. However, many of these data are dispersed in the literature and were published in scientific articles or monographs. Consequently, each researcher or at least each research group had to build their own up-to-date database of reference data from the literature. To overcome these restrictions, to facilitate work with lead isotope reference data and particularly to make the data FAIR, i.e., findable, accessible, interoperable and reusable (Wilkinson et al. 2016), these published data are compiled and transferred into a uniform layout. They are further enhanced with additional metadata to facilitate their use in raw material provenance studies. Currently, the database is restricted to ores and minerals as these are the most relevant materials for provenance studies of ancient metals. Future updates will include hitherto uncovered regions but also additional data from countries already present. Slag and other metallurgical (by-) products from ancient sites in close vicinity to ore deposits generally are a genuine representation of the ores utilised in historic times. As such, they are highly relevant for provenance studies and an extension to these materials is therefore planned. GlobaLID is a representation of the collective work of researchers on Pb isotope studies. As such, the database is seen as a community engagement project that invites scientists all over the world to become active contributors of GlobaLID. The initiators of the database dedicate their effort to the continuation and maintenance of the database but only the support of the whole community will allow a rapid and successful growth of GlobaLID.
This dataset is a continuously growing collection of lead isotope reference data. Lead isotopes are an established method to reconstruct the raw material provenance of archaeological objects. They are typically applied to artefacts made of copper, lead, silver, and their alloys. However, also the raw ma- terial provenance of other materials such as glass, pigments and pottery was already investigated us- ing lead isotopes. To successfully reconstruct the origin of the raw material, lead isotope signatures from as many as possible suitable raw material occurrences must be known. In the past, large-scaled research projects were carried out to characterise ore deposits especially in the Mediterranean area and Western Eu- rope. However, many of these data are dispersed in the literature and were published in scientific articles or monographs. Consequently, each researcher or at least each research group had to build their own up-to-date database of reference data from the literature. To overcome these restrictions, to facilitate work with lead isotope reference data and particularly to make the data FAIR, i.e., finda- ble, accessible, interoperable and reusable (Wilkinson et al. 2016), these published data are compiled and transferred into a uniform layout. They are further enhanced with additional metadata to facili- tate their use in raw material provenance studies. Currently, the database is restricted to ores and minerals as these are the most relevant materials for provenance studies of ancient metals. Future updates will include hitherto uncovered regions but also additional data from countries already present. Slag and other metallurgical (by-) products from ancient sites in close vicinity to ore deposits generally are a genuine representation of the ores uti- lised in historic times. As such, they are highly relevant for provenance studies and an extension to these materials is therefore planned. GlobaLID is a representation of the collective work of researchers on Pb isotope studies. As such, the database is seen as a community engagement project that invites scientists all over the world to be- come active contributors of GlobaLID. The initiators of the database dedicate their effort to the con- tinuation and maintenance of the database but only the support of the whole community will allow a rapid and successful growth of GlobaLID.
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.
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