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Found 7 results.

Geochemical, isotopic, geochronological data and assimilation plus fractional crystallization model of The Pleiades Volcanic Field (Northern Victoria Land, Antarctica)

This dataset presents a set of geographical, geochemical and isotopic data, microphotos of thin sections and geochemical binary variation diagrams of sixteen samples of volcanic rocks collected in The Pleiades Volcanic Field, Northern Victoria Land, Antarctica (≈ 72° 42’ S; 165° 43’ E), made up of some 20 monogenetic, partly overlapping scoria and spatter cones, erupted in the last 900 ka, cropping out from the ice close to the head of Mariner Glacier. First two files of dataset (kmz files) contain locations of volcanic centres of The Pleaides Volcanic Fiels and the locations of the collected samples. File #3 contains analytical results of full major element, trace element and radiogenic (Sr, Nd, Pb) isotopic data of collected samples. File #4 contains analytical details of Ar-Ar geochronological data. File #5A and 5B contains modelling results, respectively, of major elements and trace elements-Sr isotope ratios of Assimilation plus Crystal Fractionation (AFC) applied to selected samples of The Pleiades Volcanic Field. Other files are images containing high-resolution pictures collected through optical microscopy of thin sections of collected samples showing their most important petrographic features and binary geochemical diagrams of variation of major elements and selected trace elements against SiO2 (wt%). This data are supplement to a manuscript currently submitted to G3 – Geochemistry, Geophysics, Geosystems, and are used to describe the main petrographic and geochemical features of the volcanic products outcropping at the Pleiades, define the characters of their mantle source, to define their evolutionary patterns. Through these data, we observed an unusual fractionation trend for this kind of volcanic fields, with a large assimilation rate of crustal material, ane we hypothesize a role of the thick-ice cap able to suppress the eruption potential and to increase the residence times of magma in crustal chambers.

Luminescence dating of sediment samples from NEP 1 and NEP 3, Nördlingen, southern Germany

We established a luminescence based chronology by dating 7 samples collected from profiles NEP 1 and NEP 3. The methods allows to determine the last sunlight exposure of sediment grains (commonly quartz and feldspar). All measurements were conducted in the luminescence laboratory within the Geo-and Environmental research center in Tübingen. We used a so called pIR150 protocol on polyminerals. The results point to various periods of deposition between approximately 1-8 ka.

Provenance and pressure-temperature-time-deformation evolution of Indian crust in central Myanmar

Other

Survey questions and responses to the G-Chron 2019 proficiency test

This data publication consists of two parts: (1) the questionnaire for round 1 of the G-Chron proficiency test as provided to the participating laboratories via the on-line data submission portal, and (2) the complete data set of submitted results. The results of the survey are published as Scientific Technical Report - Data (STR 21/06, Webb et al., 2020). The questionnaire is structured into distinct segments. The first “metadata segment” allowed each laboratory to report key parameters describing their analytical technique. This part was structured as five independent tracks based on laboratory technique: isotope dilution thermal ionization mass spectrometry (ID-TIMS), secondary ion mass spectrometry (SIMS), laser ablation inductively coupled sector field mass spectrometry (LA-ICP-MS: SF), laser ablation inductively coupled quadrupole / time-of-flight mass spectrometry (LA-ICP-MS: Quad&ToF), and “other”. When reporting results a given laboratory was to select a single one of these options and then was provided a series of questions relevant to that specific method. The second segment of the questionnaire was provided to all laboratories for them to submit their determined age results. The on-line portal required submission of the determined age and uncertainty for both the 206Pb/238U and 207Pb/206Pb chronometers. Submission of results for the 208Pb/232Th chronometer was optional. Both the April 2020 report and the subsequent manuscript for publication are based on the table that forms the second part of this document. This contains both the reported age values and information about key aspects of each laboratory’s analytical method. In a small number of cases the input data were corrupted due to an apparent incompatibility between the data portal and the character set used by the submitting laboratory. Where the intent of the laboratory reporting was obvious these have been corrected. For two of the reporting laboratories there a software malfunction resulted in their submissions being classified as “other technique”. These data have now been reassigned to their correct technique categories, but the report has not been accordingly modified. All age values are in Ma. The software specified that uncertainty values should be reported as 1s or 1SE, depending on the nature of the value being addressed, though in a number of instances this instruction appears not to have been applied.

sandbox - an R tool for creating and analysing synthetic sediment sections

sandbox is an R-tool for probabilistic numerical modelling of sediment properties. A flexible framework for definition and application of time/depth- based rules for sets of parameters for single grains that can be used to create artificial sediment profiles. Such profiles can be used for virtual sample preparation and synthetic, for instance, luminescence measurements.

PALEOENVI: The late Quaternary palaeoenvironment of the Pannonian Basin (SE Europe)

ERA.Net-RUS: Weathering and landscape evolution in fragile alpine and subarctic regions

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)

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