The dataset contains chemical analyses from the well-characterised Hakgala field site in the tropical Highlands of Sri Lanka. This site is located on a road cut between Nuwara Elia and Welimada (06.92923° N, 80.81834° E, 1753 m altitude), bordering a 12 km^2 natural forest reserve consisting of pristine, mature, stable upper montane rain forest, close to the Hakgala Botanical Garden. A deeply weathered regolith depth profile (ca. 10 m) developed on a hillslope underlain by charnockite bedrock. Adjacent to the regolith profile ecologically pristine catchments (>1 km^2) are drained by small creeks.Here, data on samples of all compartments of the Critical Zone (defined as the near surface layer of the Earth extending from the bottom of the weathering zone to the top of the tree canopy) are reported. The dataset compiles published (Hewawasam et al., 2013, GCA, 118, 202-230) and new data (Schuessler et al., 2018, Chemical Geology) of element concentrations, stable Mg isotopes, and radiogenic Sr isotope ratios on stream water (time series sampling 2010-2013), vegetation, soil, saprolite (depth profile sampling), weathered bedrock (corestones), and unweathered bedrock. From this data, weathering indicators such as the chemical depletion fraction (CDF) and the element mass transfer coefficients (Tau) were calculated and reported in the dataset.The samples used for these analyses have been assigned with International Geo Sample Numbers (IGSN, www.igsn.org). Details on sampling locations are provided via IGSN links in the tables and in the related work section on the DOI Landing Page at GFZ Data Services. Moreover, the IGSN data can be accessed by adding the IGSN after igsn.org, e.g. igsn.org/GFFB1003V. Further details on sampling and locations are provided in Hewawasam et al. (2013, GCA, 118, 202-230).This publication contains an annotated summary table serving as a supplementary table for Schuessler et al. (2018, Chemical Geology) in pdf and xlsx (Microsoft Excel) formats. In addition, separate tables reflecting differing samples and methodologies for input into statistical software are provided as comma separated files. Column headers for all tables are explained in a separate csv file (Data columns headers for tables S1 to S3.csv). The analytical methodologies used to generate the data are described in the data description file.
This data set contains chemical and Mg isotope analyses of time-series creek water, subsurface flow (0-15cm and 15-150cm), vegetation, regolith, clay-sized fraction and exchangeable fraction of regolith from a catchment of the Black Forest, Germany. This dataset is a following work of “Uhlig, D., & von Blanckenburg, F. (2019)", in which major and trace elements concentrations and 87Sr/86Sr isotope data was reported on the same batch of samples. With the new Mg isotope analyses, we investigated the potential controlling factors on water Mg isotopic composition, and we found exchange reactions in our catchment are a primary control on water chemistry. To further interrogate this finding, a batch of adsorption and desorption experiments using soil samples from our study site were carried out. The adsorption and desorption experiment results are also included here. This combination of field research and lab experiments informs about processes fractionating Mg in the critical zone – with the role of the exchangeable pool highlighted as particularly important – and further verifies the potential of Mg isotopes as a tool in tracing continental weathering process. Samples are assigned with International Geo Sample Numbers (IGSN), a globally unique and persistent Identifier for physical samples.
Chemical weathering of rocks is extremely important for the generation of soils, for the evolution of landscape, and as a main source of inorganic nutrients for plant growth and therefore for life. Due to climate warming, additional areas will become ice-free and subject to weathering and soil formation. Large parts of the European Alps and Russia including the Altai mountains of Asia were glaciated during the last ice age. Glaciers and periods of glaciation have a significant impact on global weathering. Proglacial environments are important for the understanding of global CO2 cycling on glacial/interglacial timescales as they made up a significant amount of the global land surface during the Quaternary due to the advance and retreat of glaciers and ice sheets. Consequently, the currently occurring worldwide climate changes are fuelling a growing interest in the effect that the state factors such as climate, parent material, topography, organisms and time are having on the landscape and consequently soil evolution. The concept of the factors for soil formation is enjoying a broad renaissance as the worlds people become aware of how the rich resources of soils and ecosystems are being wasted. Consequently, weathering mechanisms as a scientific topic have gained much in importance over the last two decades. The alteration mechanisms are nonetheless poorly understood and further research is required to explain soil and landscape evolution and their response to changing environmental conditions. A main gap in knowledge exists about the velocity of (clay) mineral transformations or formations in soils or material starting to be a soil in high alpine and arctic climate zones. Especially little is known about the initial stages of weathering and soil formation, i.e. during the first decades to centuries of soil genesis. Two different kinds of soil production functions are discussed in literature: a) soil evolution and consequently weathering can be modelled using a humped function which means that soil production and weathering is maximised at a certain time or b) models using an exponential function are often applied. Accordingly, production and weathering exponentially decreases with time. Due to the two different soil production concepts, soil formation and weathering can have both a slow or high reactivity at the initial stage. A challenge is now to test the applicability of the existing soil production functions and as yet unknown forms to different kinds of situations. A main aim of the proposed collaboration and scientific exchange is to compare existing and new datasets (where the main applicants have access to) on weathering and soil evolution in the Alps (Swiss and Italian Alps), the Altai mountains (Siberia, Russian Altai) and the Polar Urals (the Ural Mountains, Russia). In addition, datasets from the Wind River Range (Rocky Mountains, USA) will be available. (abridged text)