[vc_empty_space][vc_empty_space]
Vivianite formation in ferruginous sediments from Lake Towuti, Indonesia
Vuillemin A.a,i, Friese A.a, Wirth R.a, A. Schuessler J.a, M. Schleicher A.a, Kemnitz H.a, Lucke A.b, W. Bauer K.c,j, Nomosatryo S.a,d, Von Blanckenburg F.a, Simister R.c, G. Ordonez L.e, Ariztegui D.e, Henny C.d, M. Russell J.f, Bijaksana S.g, Vogel H.h, A. Crowe S.c,j, Kallmeyer J.a
a GFZ German Research Centre for Geosciences, Helmholtz Centre Potsdam, Potsdam, 14473, Germany
b Jülich Research Center, Institute of Bio- and Geosciences, Agrosphere, 52428, Germany
c Department of Earth Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, V6T 1Z4, Canada
d Research Center for Limnology, Indonesian Institute of Sciences (LIPI), Cibinong-Bogor, Indonesia
e Department of Earth Sciences, University of Geneva, Geneva, 1205, Switzerland
f Department of Earth Environmental, and Planetary Sciences, Brown University, Providence, 02912, United States
g Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Bandung, 50132, Indonesia
h Institute of Geological Sciences and Oeschger, Centre for Climate Change Research, University of Bern, Bern, 3012, Switzerland
i Department of Earth and Environmental Science, Paleontology and Geobiology Ludwig-Maximilians, Universität München, Munich, 80333, Germany
j Department of Earth Sciences, University of Hong Kong, Hong Kong
[vc_row][vc_column][vc_row_inner][vc_column_inner][vc_separator css=”.vc_custom_1624529070653{padding-top: 30px !important;padding-bottom: 30px !important;}”][/vc_column_inner][/vc_row_inner][vc_row_inner layout=”boxed”][vc_column_inner width=”3/4″ css=”.vc_custom_1624695412187{border-right-width: 1px !important;border-right-color: #dddddd !important;border-right-style: solid !important;border-radius: 1px !important;}”][vc_empty_space][megatron_heading title=”Abstract” size=”size-sm” text_align=”text-left”][vc_column_text]© Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License.Ferruginous lacustrine systems, such as Lake Towuti, Indonesia, are characterized by a specific type of phosphorus cycling in which hydrous ferric iron (oxyhydr) oxides trap and precipitate phosphorus to the sediment, which reduces its bioavailability in the water column and thereby restricts primary production. The oceans were also ferruginous during the Archean, thus understanding the dynamics of phosphorus in modern-day ferruginous analogues may shed light on the marine biogeochemical cycling that dominated much of Earth’s history. Here we report the presence of large crystals ( > 5 mm) and nodules (> 5 cm) of vivianite – a ferrous iron phosphate – in sediment cores from Lake Towuti and address the processes of vivianite formation, phosphorus retention by iron and the related mineral transformations during early diagenesis in ferruginous sediments. Core scan imaging, together with analyses of bulk sediment and pore water geochemistry, document a 30m long interval consisting of sideritic and non-sideritic clayey beds and diatomaceous oozes containing vivianites. Highresolution imaging of vivianite revealed continuous growth of crystals from tabular to rosette habits that eventually form large (up to 7 cm) vivianite nodules in the sediment. Mineral inclusions like millerite and siderite reflect diagenetic mineral formation antecedent to the one of vivianite that is related to microbial reduction of iron and sulfate. Together with the pore water profiles, these data suggest that the precipitation of millerite, siderite and vivianite in soft ferruginous sediments stems from the progressive consumption of dissolved terminal electron acceptors and the typical evolution of pore water geochemistry during diagenesis. Based on solute concentrations and modeled mineral saturation indices, we inferred vivianite formation to initiate around 20m depth in the sediment. Negative 56Fe values of vivianite indicated incorporation of kinetically fractionated light Fe2C into the crystals, likely derived from active reduction and dissolution of ferric oxides and transient ferrous phases during early diagenesis. The size and growth history of the nodules indicate that, after formation, continued growth of vivianite crystals constitutes a sink for P during burial, resulting in long-term P sequestration in ferruginous sediment.[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Author keywords” size=”size-sm” text_align=”text-left”][vc_column_text][/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Indexed keywords” size=”size-sm” text_align=”text-left”][vc_column_text][/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Funding details” size=”size-sm” text_align=”text-left”][vc_column_text][{‘$’: ‘Acknowledgements. This research was carried out with partial support from the International Continental Scientific Drilling Program (ICDP); the U.S. National Science Foundation (NSF); the German Research Foundation (DFG); the Swiss National Science Foundation (SNSF); PT Vale Indonesia; the Ministry of Research, Education, and Higher Technology of Indonesia (RISTEK); Brown University; the University of Minnesota; the University of Geneva; GFZ German Research Centre for Geosciences; the Natural Sciences and Engineering Research Council of Canada (NSERC); and Genome British Columbia. This study was financially and logistically supported by the DFG ICDP priority program through grants to Jens Kallmeyer (KA 2293/8-1) and Aurèle Vuillemin (VU 94/1-1), an SNSF grant to Aurèle Vuillemin (P2GEP2_148621), and an NSERC Discovery grant (0487) to Sean A. Crowe.’}, {‘$’: ‘Financial support. This research has been supported by the Swiss’}][/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”DOI” size=”size-sm” text_align=”text-left”][vc_column_text]https://doi.org/10.5194/bg-17-1955-2020[/vc_column_text][/vc_column_inner][vc_column_inner width=”1/4″][vc_column_text]Widget Plumx[/vc_column_text][/vc_column_inner][/vc_row_inner][/vc_column][/vc_row][vc_row][vc_column][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][/vc_column][/vc_row]