PD Dr. Florian Scholz

Research Division Marine Biogeochemistry

Research Unit Marine Geosystems

Emmy Noether-Research Group

ICONOX - Iron cycling in continental margin sediments and the nutrient and oxygen balance of the ocean


Wischhofstraße 1-3, 8E-109
24148 Kiel
Phone: +49 (0)431 600 2113
E-mail: fscholz(at)geomar.de

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Research Interest

My research activities focus on water-sediment interactions in marine depositional environments and their role in global biogeochemical cycles. By quantifying the turnover and fluxes of bio-essential or potentially harmful elements in the context of present and past environmental change, I seek to understand how chemical, biological and geological processes on Earth are coupled on a variety of spatial and temporal scales.

Specifically, my research group investigates water-mineral interactions and biogeochemical turnover within marine sediments and water columns. We quantify fluxes of nutrients and trace elements (and their isotopes) between Earth surface reservoirs and evaluate the impact of these fluxes on aquatic ecosystems and paleo-proxy signals. The knowledge gained in modern marine systems is used to reconstruct the evolution of biogeochemical cycles during key periods in Earth's history.




Kossack M., Scholz F., Anderson C.H., Vosteen P., Su C.-C., Mohrholz V., Zabel M. (2023) Sedimentary molybdenum and uranium cycling under seasonally contrasting redox conditions on the Namibian Shelf. Geochimica et Cosmochimica Acta 358, 174-191.

Deng K., Rickli J., Suhrhoff T. J., Du J., Scholz F., Severmann S., Yang S., McManus J., Vance D. (2023) Dominance of benthic fluxes in the oceanic beryllium budget and implications for paleo-denudation records. Science Advances 9, doi: 10.1126/sciadv.adg3702.

Retschko A.-K., Vosteen P., Plass A., Welter E., Scholz F. (2023) Comparison of sedimentary iron speciation by sequential extraction and x-ray absorption spectroscopy. Marine Chemistry 252, 104249.

Cao Z., Rao X., Li Y., Hong Q., Wei L., Yu Y., Ehlert C., Liu B., Siebert C., Hathorne E.C., Zhang Z., Scholz F., Kasten S., Frank M. (2023) Stable Barium Isotope Fractionation in Pore Waters of
Estuarine Sediments. Geochemistry Geophysics Geosystems 24, e2023GC010907. doi.org/10.1029/2023GC010907.

Geilert S., Frick D. A., Garbe-Schönberg D., Scholz F., Sommer S., Grasse P., Vogt C., Dale A. W. (2023) Coastal El Niño triggers rapid marine silicate alteration on the seafloor. Nature Communications. doi: 10.1038/s41467-023-37186-5.

Scholz F., Cheng J., Zhang Z., Vosteen P., Siebert C., Frank M. (2023) Benthic-pelagic coupling and isotopic fractionation of barium in Kiel Bight, SW Baltic Sea. Frontiers in Marine Science 10:1101095. doi: 10.3389/fmars.2023.1101095.


Perner M., Wallmann K., Adam-Beyer N., Hepach H., Laufer-Meiser K., Böhnke S., Diercks I., Bange H. W., Indenbirken D., Nikeleit V., Bryce C., Kappler A., Engel A., Scholz F. (2022) Environmental changes affect the microbial release of hydrogen sulfide and methane in sediments at Boknis Eck (SW Baltic Sea). Frontiers in Microbiology 13:1096062. doi: 10.3389/fmicb.2022.1096062.

Vosteen P., Spiegel T., Gledhill M., Frank M., Zabel M., Scholz F. (2022) The fate of sedimentary reactive iron at the land-ocean interface: A case study from the Amazon shelf. Geochemistry Geophysics Geosystems e2022GC010543. doi.org/10.1029/2022GC010543.

Chuang P.-C., Anderson C.H., Kossack M., Fabian J., Su C.-C., Vosteen P., Zabel M., Scholz F., Schulz-Vogt H., Sommer S., Dale A.W. (2022) Nutrient turnover by large sulfur bacteria on the Namibian mud belt during the low productivity season. Frontiers in Marine Science. doi.org/10.3389/fmars.2022.929913.

Wallmann K., Diesing M., Scholz F., Rehder G., Dale A.W., Fuhr M., Suess E. (2022) Erosion of carbonate-bearing sedimentary rocks may close the alkalinity budget of the
Baltic Sea and support atmospheric CO2 uptake in coastal seas. Frontiers in Marine Science 9:968069. doi.org/10.3389/fmars.2022.968069.

Plass A., Retschko A.-K., Türk M., Fischer T., Scholz F. (2022) A novel device for trace metal-clean sampling of bottom water and suspended particles at the ocean’s lower boundary: The Benthic Trace Profiler. Limnology and Oceanography Methods 20, 102-114.

Wallmann K., Yosé Y.S., Hopwood M.J., Somes C.J., Dale A., Scholz F., Achterberg A., Oschlies A. (2022) Biogeochemical feedbacks may amplify ongoing and future ocean deoxygenation: A box model case study from the Peruvian oxygen minimum zone. Biogeochemistry 159, 45-67.

Salvatteci R., Schneider, R.R., Galbraith E., Field D., Blanz T., Bauersachs T., Crosta X., Martinez P., Echevin V., Scholz F., Bertrand A. (2022) Smaller fish species in a warm and oxygen-poor Humboldt Current system. Science 375, 101-104.

Bruggmann S., Gilleaudeau G.J., Romaniello S.J., Severmann S., Canfield D.E., Anbar A.D., Scholz F., Frei R. (2022) Uranium isotope cycling on the highly productive Peruvian margin. Chemical Geology 590, 120705.


Riedinger N., Scholz F., Abshire M.L., Zabel M. (2021) Persistent deep water anoxia in the eastern South Atlantic during the last ice age. Proceedings of the National Academy of Science 118, No. 49e2107034118.

Hensen C., Scholz F., Liebetrau V., Kaul N., Nuzzo M., Schmidt M., Batista L., Villinger H., Terrinha P. (2021) Oceanic strike-slip faults represent active fluid conduits in the abyssal sub-seafloor. Geology 50, 189-193.

Eroglu S., Scholz F., Salvatteci R., Siebert C., Schneider R., Frank M. (2021) The impact of postdepositional alteration on iron- and molybdenum-based redox proxies. Geology 49, 1411-1415.

Lagostino L., Frandsen S., MacGregor B.J., Glombitza C., Deng L., Fiskal A., Li J., Doll M., Geilert S., Schmidt M., Scholz F., Jørgensen B.B., Hensen C., Bernasconi S.M., Teske A., Lever M.A. (2021) Interactions of temperature and energy supply as drivers of microbial communities in hydrothermal sediment. Communications Biology 4, 1006.

Siebert C., Scholz F., Kuhnt W. (2021) A new view on the evolution of seawater molybdenum inventories before and during the Cretaceous Oceanic Anoxic Event 2. Chemical Geology 582, 120399.

Somes C. J., Dale A. W., Wallmann K., Scholz F., Yao W., Oschlies A., Muglia J., Schmittner A., Achterberg E. P. (2021) Constraining global marine iron sources and ligand-
mediated scavenging fluxes with GEOTRACES dissolved iron measurements in an ocean biogeochemical model. Global Biogeochemical Cycles. 10.1029/2021GB006948.

Plaß A., Dale A. W., Scholz F. (2021) Sedimentary cycling and benthic fluxes of manganese, cobalt, nickel, copper, zinc and cadmium in the Peruvian oxygen minimum zone. Marine Chemistry 233, 103982.

Dale A. W.,Sommer s., Lichtschlag A., Koopman D., Haeckel M., Kossel E., Deusner C., Linke P., Scholten J., Wallmann K., van Erk M., Gros J., Scholz F., Schmidt M. (2021) Defining a biogeochemical baseline for sediments at Carbon Capture and Storage (CCS) sites: an example from the North Sea (Goldeneye). International Journal of Greenhouse Gas Control 196, 103265.

Dale A. W., Paul M., Clemens D., Scholz F., Schroller-Lomnitz U., Wallmann K., Geilert S., Hensen C., Plass A., Liebetrau V., Grasse P., Sommer S. (2021) Recycling and burial of biogenic silica in an open margin oxygen minimum zone. Global Biogeochemical Cycles 35, e2020GB006583.

Spiegel T., Vosteen P., Wallmann K., Paul S. A. L., Gledhill M., Scholz F. (2021) Updated estimates of sedimentary potassium sequestration and phosphorus release on the Amazon shelf. Chemical Geology 560, 120017.

Ruffine L., Deusner C., Haeckel M., Kossel E., Toucanne S., Chéron S., Boissier A., Schmidt M., Donval J.-P., Scholz F., Guyader V., Ker S., Riboulot V. (2021) Effects of postglacial seawater intrusion on sediment geochemical characteristics in the Romanian sector of the Black Sea. Marine and Petroleum Geology 123, 104746.


Wu F., Owens J. D., Scholz F., Huang L., Li S., Riedinger N., Peterson L. C., Nielsen S. G. (2020) Sedimentary vanadium isotope signatures in low oxygen marine conditions. Geochimica et Cosmochimica Acta 284, 134-155.

Plaß A., Schlosser C., Sommer S., Dale A., Achterberg E. P., Scholz F. (2020) The control of hydrogen sulfide on benthic iron and cadmium fluxes in the oxygen minimum zone off Peru. Biogeosciences 17, 3685-3704.

Alcott L. J., Krause A. J., Hammarlund E. U., Bjerrum C. J., Scholz F., Xiong J., Hobson A. J., Neve L., Mills B. J. W., März C., Schnetger B., Bekker A., Poulton S. W. (2020) Development of iron speciation reference materials for palaeoredox analysis. Geostandards and Geoanalytical Research 44, 581-591.

Beil S., Kuhnt W., Holbourn A., Scholz F., Oxmann J., Wallmann K., Lorenzen J., Aquit M., Chellai E. H., Cretaceous Oceanic Anoxic Events prolonged by phosphorus cycle feedbacks. Climate of the Past 16, 757–782.

Geilert S., Grasse P., Doering K., Wallmann K., Ehlert C., Scholz F., Frank M., Schmidt M., Hensen C. (2020) Impact of ambient conditions on the Si isotope fractionation in marine pore fluids during early diagenesis. Biogeosciences 17, 1745–1763.

Eroglu S., Scholz F., Frank M., Siebert C. (2020) Influence of particulate versus diffusive molybdenum supply mechanisms on the molybdenum isotope composition of continental margin sediments. Geochimica et Cosmochimica Acta 273, 51-69.


Scholz F., Schmidt M., Hensen C., Eroglu S., Geilert S., Gutjahr M., Liebetrau V. (2019) Shelf-to-basin iron shuttle in the Guaymas Basin, Gulf of California. Geochimica et Cosmochimica Acta 261, 76-92.

Bruggmann S., Scholz F., Klaebe R. M., Canfield D. E., Frei R. (2019) Chromium isotope cycling in the water column and sediments of the Peruvian continental margin, Geochimica et Cosmochimica Acta 257, 224-242.

Wallmann K., Flögel S., Scholz F., Dale A., Kemena T., Steinig S., Kuhnt W. (2019) Redox seesaw drives periodic changes in Cretaceous ocean productivity and atmospheric pCO2 on orbital time scales. Nature Geoscience 12, 456-461.

Scholz F., Beil S., Flögel S., Lehmann M., Holbourn A., Wallmann K., Kuhnt W. (2019) Oxygen minimum zone-type biogeochemical cycling in the Cenomanian-Turonian Proto-North Atlantic across Oceanic Anoxic Event 2. Earth and Planetary Science Letters 517, 50-60.

Schroller-Lomnitz U., Hensen C., Dale A., Scholz F., Clemens D., Sommer S., Noffke A., Wallmann K. (2019) Dissolved benthic phosphate, iron and carbon fluxes in the Mauritanian upwelling system and implications for ongoing deoxygenation. Deep-Sea Research 143, 70-84.


Geilert S., Hensen C., Schmidt M., Liebetrau V., Scholz F., Doll M., Deng L., Fiskal A., Lever M.A., Su C.C., Schloemer S., Sarkar S., Thiel V., Berndt C. (2018) On the formation of hydrothermal vents and cold seeps in the Guaymas Basin, Gulf of California. Biogeosciences 15, 5715-5731.

Scholz F. (2018) Identifying oxygen minimum zone-type biogeochemical cycling in Earth history using inorganic geochemical proxies. Earth-Science Reviews 184, 29-45.

Scholz F., Baum M., Siebert C., Eroglu S., Dale A.W., Naumann M., Sommer S. (2018) Sedimentary molybdenum cycling in the aftermath of seawater inflow to the intermittently euxinic Gotland Deep, Central Baltic Sea. Chemical Geology 491, 27-38.

Ramalho S.P., Ribeiro C., Hensen C., Scholz F., Nuzzo M., Terrinha P., Adão H. (2018) Benthic nematode biodiversity of the Abzu, Tiamat and Michael Ivanov mud volcanoes located along the SWIM fracture zone (Gulf of Cadiz). Marine Biodiversity 48, 423-438.

Mazzini A., Scholz F., Svensen H., Hensen C., Soffian H. (2018) The geochemistry and origin of hydrothermal water erupted at Lusi, Indonesia. Marine and Petroleum Geology 90, 52-66.


Scholz F., Siebert C., Dale A., Frank M. (2017) Intense molybdenum accumulation in sediments underneath a nitrogenous water column and implications for the reconstruction of paleo-redox conditions based on molybdenum isotopes. Geochimica et Cosmochimica Acta 213, 400-417.


Geersen J., Scholz F., Linke P., Schmidt M., Lange D., Behrmann J. H., Völker D., Hensen C. (2016) Fault zone controlled seafloor methane seepage in the rupture area of the 2010 Maule Earthquake, Central Chile. Geochemistry Geophysics Geosystems 17, 4802-4813.

Scholz F., Loescher C. R., Fiskal A., Sommer S., Hensen C., Lomnitz U., Wuttig K., Göttlicher J., Kossel E., Steininger R., Canfield D. E. (2016) Nitrate-dependent iron oxidation limits iron transport in anoxic ocean regions. Earth and Planetary Science Letters 454, 272-281.

Ehlert C., Doering K., Wallmann K., Scholz F., Sommer S., Grasse P., Geilert S., Frank M. (2016) Stable silicon isotope signatures of marine pore waters - biogenic opal dissolution versus authigenic clay mineral formation. Geochimica et Comsochimica Acta 191, 102-117.

Berndt C., Hensen C., Mortera-Gutierrez C., Sarkar S., Geilert S., Schmidt M., Liebetrau V., Kipfer R., Scholz F., Doll M., Muff S., Karstens J., Planke S., Petersen S., Böttner C., Chi W. C., Moser M., Behrendt R., Fiskal A., Lever M. A., Su C. C., Deng L., Brennwald M.S., Lizarralde D. (2016) Rifting under steam - How rift magmatism triggers methane venting from sedimentary basins. Geology 44, 767-770.


Dale A., Nickelsen L., Scholz F., Hensen C., Oschlies A., Wallmann K. (2015) A revised global estimate of dissolved iron fluxes from marine sediments. Global Biogeochemical Cycles 29, 691-707.

Hensen C., Scholz F., Nuzzo M.,Valadares V., Gràcia E., Terrinha P., Liebetrau V., Kaul N., Silva S., Martínez-Loriente S., Bartolome R., Piñero E., Magalhães V.H., Schmidt M., Weise S.M., Cunha M., Hilario A., Perea H., Rovelli L., Lackschewitz K. (2015) Strike-slip faults mediate the rise of crustal-derived fluids and mud volcanism in the deep sea. Geology 43, 339-342.


Scholz F., Severmann S., McManus J., Noffke A., Lomnitz U., Hensen C. (2014) On the isotope composition of reactive iron in marine sediments: Redox shuttle versus early diagenesis. Chemical Geology 389, 48-59. 

Scholz F., McManus J., Mix A.C., Hensen C., Schneider R.R. (2014) The impact of ocean deoxygenation on iron release from continental margin sediments. Nature Geoscience 7, 433-437.

Scholz F., Severmann S., McManus J., Hensen C. (2014) Beyond the Black Sea paradigm: The sedimentary fingerprint of an open-marine iron shuttle. Geochimica et Cosmochimica Acta 127, 368-380.


Neumann T., Scholz F., Kramar U., Ostermaier M., Rausch N., Berner Z. (2013) Arsenic in framboidal pyrite from recent sediments of a shallow water lagoon of the Baltic Sea. Sedimentology 60, 1389-1404.

Scholz F., McManus J., Sommer S. (2013) The manganese and iron shuttle in a modern euxinic basin and implications for molybdenum cycling at euxinic ocean margins. Chemical Geology 355, 56-68.

Haffert L., Haeckel M., Liebetrau V., Berndt C., Nuzzo M., Reitz A., Scholz F., Schönfeld J., Perez‐Garcia C., Weise S. M. (2013) Fluid evolution and authigenic mineral paragenesis related to salt diapirism ‐ the Mercator mud volcano in the Gulf of Cadiz. Geochimica et Cosmochimica Acta 106, 261-286.

Scholz F., Hensen C., Schmidt M. , Geersen J. (2013) Submarine weathering of silicate minerals and the extent of pore water freshening at active continental margins. Geochimica et Cosmochimica Acta 100, 200‐216.


Nuzzo M., Elvert M., Schmidt M., Scholz F., Reitz A., Ferreira A., Hinrichs K.‐U., Hensen C. (2012) Impact of hot fluid advection on hydrocarbon gas production and seepage in mud volcano sediments of thick Cenozoic deltas. Earth and Planetary Science Letters 341‐344, 139‐157.

Noffke A., Hensen C., Sommer F., Scholz F., Bohlen L., Mosch T., Graco M., Wallmann K. (2012) Benthic iron and phosphorus fluxes across the Peruvian oxygen minimum zone. Limnology and Oceanography 57, 851‐867.


Scholz F., Hensen C., Noffke A., Rohde A., Liebetrau V., Wallmann K. (2011) Early diagenesis of redox‐sensitive metals in the Peru upwelling area: response to ENSO‐related oxygen fluctuations in the water column. Geochimica et Cosmochimica Acta 75, 7257‐7276.

Bohlen L., Sommer S., Dale A., Mosch T., Hensen C., Noffke A., Scholz F., Wallmann K. (2011) Benthic nitrogen cycling traversing the Peruvian oxygen minimum zone. Geochimica et Cosmochimica Acta 75, 6094‐6111.

Völker D., Scholz F., Geersen J. (2011) Analysis of submarine landsliding in the rupture area of the 27 February 2010 Maule earthquake, Central Chile. Marine Geology 28, 79‐89.

Reitz A., Pape T., Haeckel M., Schmidt M., Berner U., Scholz F., Liebetrau V., Aloisi G., Weise S.M. , Wallmann K. (2011) Sources of fluids and gases expelled at cold seeps offshore Georgia, eastern Black Sea. Geochimica et Cosmochimica Acta 75, 3250‐3268.

2010 and prior

Scholz F., Hensen C., De Lange G.J., Haeckel M., Liebetrau V., Meixner A., Reitz A., Romer R.L. (2010) Lithium isotope geochemistry of marine pore waters: Insights from cold seep fluids. Geochimica et Cosmochimica Acta 74, 3459‐3475.

Scholz F., Hensen C., Lu Z., Fehn U. (2010) Controls on the 129I/I ratio of deep‐seated marine interstitial fluids: 'old' organic versus fissiogenic 129‐iodine. Earth and Planetary Science Letters 294, 27‐36.

Feseker T., Brown K.R., Blanchet C., Scholz F., Nuzzo M., Reitz A., Schmidt M., Hensen C. (2010) Active mud volcanoes on the upper slope of the western Nile deep‐sea fan – first results from the P362/cruise of R/V Poseidon, Geo‐Marine Letters. DOI 10.1007/s00367‐010‐0192‐0.

Nuzzo M., Hornibrook E.R.C., Gill F., Hensen C., Pancost R.D., Haeckel M., Reitz A., Scholz F., Magalhães V.H., Brückmann W., Pinheiro L.M. (2009) Origin of light volatile hydrocarbon gases in mud volcano fluids, Gulf of Cadiz – Evidence for multiple sources and transport mechanisms in active sedimentary wedges. Chemical Geology 266, 359‐372.

Scholz F., Hensen C., Reitz A., Romer R.L., Liebetrau V., Meixner A., Weise S.M., Haeckel M. (2009) Isotopic evidence (87Sr/86Sr, δ7Li) for alteration of the oceanic crust at deep‐rooted mud volcanoes in the Gulf of Cadiz, NE Atlantic Ocean. Geochimica et Cosmochimica Acta 73, 5444‐5459 (Corrigendum published in 2015, Geochimica et Cosmochimica Acta 152, 52-53).

Scholz F., Neumann T. (2007) Trace element diagenesis in pyrite‐rich sediments of the Achterwasser lagoon, SW Baltic Sea. Marine Chemistry 107, 516‐532.