Description: 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.
Global identifier:
Doi(
"10.5880/fidgeo.2020.009",
)
Origins: /Wissenschaft/Helmholtz-Gemeinschaft/GFZ
Tags: Atmosphärische CO2-Konzentration ? Beryllium ? Meerwasser ? Erosion ? Daten ? Energie ? Sediment ? Niederschlag ? 10Be ? EARTH SCIENCE > LAND SURFACE > EROSION/SEDIMENTATION > EROSION ? EARTH SCIENCE > LAND SURFACE > EROSION/SEDIMENTATION > SEDIMENTS ? EARTH SCIENCE > LAND SURFACE > EROSION/SEDIMENTATION > WEATHERING ? EARTH SCIENCE > OCEANS > MARINE SEDIMENTS > PARTICLE FLUX ? EARTH SCIENCE > OCEANS > MARINE SEDIMENTS > SEDIMENT CHEMISTRY ? EARTH SCIENCE > OCEANS > MARINE SEDIMENTS > SEDIMENT COMPOSITION ? EARTH SCIENCE > OCEANS > MARINE SEDIMENTS > TERRIGENOUS SEDIMENTS ? EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > MARINE GEOCHEMISTRY ? EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > RADIONUCLIDES ? EARTH SCIENCE > SOLID EARTH > GEOCHEMISTRY > GEOCHEMICAL PROCESSES > CHEMICAL WEATHERING ? EARTH SCIENCE > SOLID EARTH > GEOCHEMISTRY > GEOCHEMICAL PROPERTIES > CHEMICAL CONCENTRATIONS ? EARTH SCIENCE > SOLID EARTH > GEOCHEMISTRY > GEOCHEMICAL PROPERTIES > ISOTOPE RATIOS ? EARTH SCIENCE > SOLID EARTH > GEOCHEMISTRY > GEOCHEMICAL PROPERTIES > ISOTOPES ? EARTH SCIENCE > SOLID EARTH > GEOCHEMISTRY > MARINE GEOCHEMICAL PROCESSES > CHEMICAL DECOMPOSITION ? EARTH SCIENCE > SOLID EARTH > GEOMORPHIC LANDFORMS/PROCESSES > FLUVIAL PROCESSES > WEATHERING ? authigenic clay ? compound material > sedimentary material > chemical sedimentary material ? compound material > sedimentary material > clastic sedimentary material ? compound material > sedimentary material > sediment ? compound material > sedimentary material > sediment > mud size sediment ? cosmogenic nuclide ? geological process > sedimentation (geology) ? reverse weathering ?
License: cc-by/4.0
Language: Englisch/English
Issued: 2020-01-01
Time ranges: 2020-01-01 - 2020-01-01
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