Dataset Information

Chromium Cycling in Redox-Stratified Basins Challenges δ⁵³Cr Paleoredox Proxy Applications.

ABSTRACT: Chromium stable isotope composition (δ⁵³Cr) is a promising tracer for redox conditions throughout Earth's history; however, the geochemical controls of δ⁵³Cr have not been assessed in modern redox-stratified basins. We present new chromium (Cr) concentration and δ⁵³Cr data in dissolved, sinking particulate, and sediment samples from the redox-stratified Lake Cadagno (Switzerland), a modern Proterozoic ocean analog. These data demonstrate isotope fractionation during incomplete (non-quantitative) reduction and removal of Cr above the chemocline, driving isotopically light Cr accumulation in euxinic deep waters. Sediment authigenic Cr is isotopically distinct from overlying waters but comparable to average continental crust. New and published data from other redox-stratified basins show analogous patterns. This challenges assumptions from δ⁵³Cr paleoredox applications that quantitative Cr reduction and removal limits isotope fractionation. Instead, fractionation from non-quantitative Cr removal leads to sedimentary records offset from overlying waters and not reflecting high δ⁵³Cr from oxidative continental weathering.

SUBMITTER: Janssen DJ

PROVIDER: S-EPMC9787902 | biostudies-literature | 2022 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Chromium Cycling in Redox-Stratified Basins Challenges δ53Cr Paleoredox Proxy Applications.

Janssen David J DJ Rickli Jörg J Wille Martin M Sepúlveda Steiner Oscar O Vogel Hendrik H Dellwig Olaf O Berg Jasmine S JS Bouffard Damien D Lever Mark A MA Hassler Christel S CS Jaccard Samuel L SL

Geophysical research letters 20221028 21

Chromium stable isotope composition (δ53Cr) is a promising tracer for redox conditions throughout Earth's history; however, the geochemical controls of δ53Cr have not been assessed in modern redox-stratified basins. We present new chromium (Cr) concentration and δ53Cr data in dissolved, sinking particulate, and sediment samples from the redox-stratified Lake Cadagno (Switzerland), a modern Proterozoic ocean analog. These data demonstrate isotope fractionation dur ...[more]

PMID: 36589775

Similar Datasets

Project description:In this study, hybrids of nanoporous MIL-101(Cr) and MIL-53(Al) were synthesized using a hydrothermal method for various time periods, ranging from 8 to 40 h. The prepared materials were characterized by powder X-ray diffraction (PXRD) and elemental analysis, and their specific surface areas were measured by N2 sorption at 77 K using the Brunauer-Emmett-Teller (BET) method. To investigate the practical application of these materials, the pure carbon dioxide and methane adsorption capacities of the samples were determined using the volumetric method. The Langmuir model was used to fit the CO2 and CH4 isotherms. Extended Langmuir (EL) equations and the ideal adsorbed solution theory (IAST) models were used to obtain the CO2/CH4 selectivity. The sample with the highest BET specific surface area was selected as a candidate for further investigations. The thermal stability of the selected sample was investigated by thermogravimetric analysis (TGA). Scanning electron microscopy (SEM) was used to characterize the sample morphology. XRD results showed that the sample synthesized over the shortest time corresponded to MIL-101(Cr), while the sample synthesized over the longest time was in agreement with MIL-53(Al). Samples synthesized for time periods between these two limits were assumed to be composites of both MIL-53(Al) and MIL-101(Cr). TGA results indicated that the hybrid materials were thermally stable at temperatures about 100 °C higher than for pure MIL-101(Cr). The BET specific surface area (1746 m2 g-1) and CO2 adsorption capacity (16 mmol g-1) of the selected hybrid sample were about 50% and 35% higher, respectively, compared with those of pure MIL-53(Al), but 30% and 20% lower, respectively, compared with those of pure MIL-101(Cr). Binary adsorption modeling showed the high selectivity of the MIL-101(Cr) and MIL-53(Al) hybrid material for CO2 with a minimum separation factor of about 60 at 298 K. This value was much higher than those reported previously and those observed in this work for the original MIL-101(Cr) or MIL-53(Al). These results demonstrated that the hybrid of MIL-101(Cr) and MIL-53(Al) was a promising material for selective CO2 capture from natural and biogas.

Dataset Information

Chromium Cycling in Redox-Stratified Basins Challenges δ⁵³Cr Paleoredox Proxy Applications.

Publications

Chromium Cycling in Redox-Stratified Basins Challenges δ<sup>53</sup>Cr Paleoredox Proxy Applications.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets