Allyson Tessin's research while affiliated with University of Leeds and other places

... Sensitivity tests of small diatom dissolution on porewater δ 30 Si are shown in Figure S2 in Supporting Information S1, which exemplifies the failure of simulating the observations if assuming small diatom dissolution. Similar 30 Si-depleted porewater data have been reported for the Guaymas Basin, the Barents Sea, and the Antarctic region, and interpreted as indicators for dissolution of terrigenous clay and metal oxides apart from biogenic opal (Closset et al., 2022;Geilert, Grasse, Doering, et al., 2020;Ward et al., 2022). In the southern Mariana Trench sediments, however, dissolution of lithogenic silicates does not necessarily contribute to the low porewater δ 30 Si values because simple dissolution of E. rex frustules that represent the predominant diatom species can explain the observations. ...

... The seawater pH at the sediment-water interface as well as of the pore water, also strongly modulates carbon burial (Keil, 2017;LaRowe et al. 2020;Freitas et al. 2022). As the core site lies in the oxygen-deficient zone, the pH at the sediment-water interface is likely to strongly modulate carbon burial in the sediments, before the remineralization of both the organic matter and CaCO 3 . ...

... In addition to dissolution of biogenic Si from settled diatom frustules, the dissolution of primary minerals would result in relatively light δ 30 Si DSi (Frings et al., 2016), while heavier δ 30 Si DSi signatures are expected if authigenic clay formation (Ehlert et al., 2016;Opfergelt & Delmelle, 2012) and Si adsorption onto ferric hydroxides (Zheng et al., 2016) removes lighter isotopes from pore waters. Pore water δ 30 Si DSi signatures have been determined for the Barents Sea and estimated for the Chukchi Sea at values ranging between −0.51 and +1.69‰ Ward et al., 2021), which is significantly lighter than the values expected for the northwestern Laptev Sea (∼+1.8‰, see above), indicating that preformed δ 30 Si DSi values prior to biological production were either different or that other dissolution processes are at play in the Laptev Sea. ...

... biogeochemical cycling of elements and their isotopes (Anderson, 2020), and particularly the GEOTRAC-ES 2017 Intermediate Data Product (IDP2017, Schlitzer et al., 2018) that includes isotope data of many dissolved constituents in seawater from 39 cruises collected between 2007 and 2014. We focus specifically on C, N, and Si, while a synthesis of bioactive trace elements and their isotopes is provided in a companion manuscript (Horner et al., 2021). ...

... The Arctic Ocean ( Figure 1) is experiencing rapid, humanled change (Thomas et al., 2022). It is warming at three times the global mean rate (Dai et al., 2019;AMAP, 2021) leading to a cycle of sea ice loss, decreasing ocean albedo, increasing poleward ocean heat transport and increasing polar cloud cover (Holland and Bitz, 2003). ...

... However, the bottom samples with the highest DSi excess have the lowest Δδ 30 Si DSi (+0.45 and +0.16‰ for stations 7 and 6 from 2013 to 2014, respectively), which agrees with benthic Si release as the main source of [DSi] excess. Elevated benthic Si fluxes have been inferred for the Siberian Interior Shelf Seas and other shallow regions of the Arctic Ocean März et al., 2015März et al., , 2022Sun et al., 2021). In addition to dissolution of biogenic Si from settled diatom frustules, the dissolution of primary minerals would result in relatively light δ 30 Si DSi (Frings et al., 2016), while heavier δ 30 Si DSi signatures are expected if authigenic clay formation (Ehlert et al., 2016;Opfergelt & Delmelle, 2012) and Si adsorption onto ferric hydroxides (Zheng et al., 2016) removes lighter isotopes from pore waters. ...

... The composition of marine SPM depends on a number of closely related biological and physicochemical processes occurring in the water column (e.g., microalgae blooms, degradation of organic matter, redox reactions), as well as on hydrological conditions. The study of some elements in SPM is of great concern for establishing the patterns of sediment formation, which can be useful for paleooceanological reconstructions [13]. The distribution of SPM is governed by the principles of the circum-continental and climatic zones [1]. ...

... Because no information about the spatial distribution of FeOOH fluxes is currently available, we assumed a globally uniform J FeOOH,T of 1110 µmol m −2 d −1 , to be consistent with previous work [9]. However, in reality, the deposition of FeOOH is not uniform but varies geographically [69]. This choice mainly affects the estimated global flux, and does not greatly alter our conclusions on the relative impact of bioturbation on sedimentary Fe release and isotope dynamics (as these are independent of the FeOOH influx; see below). ...

... The Ba/Al weight ratio (Ba/Al) lithog ) in the upper continental crust varies from 0.0040 to 0.0075 (Dymond et al., 1992;Gingele and Dahmke, 1994;Hayes et al., 2021). According to these researchers, accumulation rate of the biogenic Ba (excess Ba associated with organic matter) in the Atlantic pelagic zone is as much as 0.5-1.0 ...

... Alternatively, Fe(total) HCl -which represents high surface area, reactive iron oxides such as ferrihydrite and lepidocrocite, as well as surface-sorbed iron (Poulton and Canfield, 2005) could be associated with SOC through co-precipitation and sorption (Faust et al., 2021;Jeewani et al., 2021). In the meander soils, high Fe(total) HCl likely contributes to high SOC concentrations through the formation of mineral-associated organic matter, particularly short-range order Fe (III)-hydroxides. ...