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Université de Fribourg

Early diagenetic imprint on temperature proxies in holocene corals: a case study from french polynesia

Rashid, Rashid ; Eisenhauer, Anton ; Liebetrau, Volker ; Fietzke, Jan ; Böhm, Florian ; Wall, Marlene ; Krause, Stefan ; Rüggeberg, Andres ; Dullo, Wolf-Christian ; Jurikova, Hana ; Samankassou, Elias ; Lazar, Boaz

In: Frontiers in Earth Science, 2020, vol. 8, p. -

Coral-based reconstructions of sea surface temperatures (SSTs) using Sr/Ca, U/Ca and δ18O ratios are important tools for quantitative analysis of past climate variabilities. However, post-depositional alteration of coral aragonite, particularly early diagenesis, restrict the accuracy of calibrated proxies even on young corals. Considering the diagenetic effects, we present new Mid to Late...

Université de Fribourg

Assessing the impact of diagenesis on foraminiferal geochemistry from a low latitude, shallow-water drift deposit

Stainbank, Stephanie ; Spezzaferri, Silvia ; Boever, Eva De ; Bouvier, Anne-Sophie ; Chilcott, Colin ; Leau, Erica S.de ; Foubert, Anneleen ; Kunkelova, Tereza ; Pichevin, Laetitia ; Raddatz, Jacek ; Rüggeberg, Andres ; D.Wright, James ; M.Yu, Siyao ; Zhang, Manlin ; Kroon, Dick

In: Earth and Planetary Science Letters, 2020, vol. 545, p. 116390

Due to their large heat and moisture storage capabilities, the tropics are fundamental in modulating both regional and global climate. Furthermore, their thermal response during past extreme warming periods, such as super interglacials, is not fully resolved. In this regard, we present high-resolution (analytical) foraminiferal geochemical (δ18O and Mg/Ca) records for the last 1800 kyr from...

Université de Fribourg

Solenosmilia variabilis-bearing cold-water coral mounds off Brazil

Raddatz, J. ; Titschack, J. ; Frank, N. ; Freiwald, A. ; Conforti, A. ; Osborne, A. ; Skornitzke, S. ; Stiller, W. ; Rüggeberg, Andres ; Voigt, Silke ; Albuquerque, A. L. S. ; Vertino, A. ; Schröder-Ritzrau, A. ; Bahr, A.

In: Coral Reefs, 2020, vol. 39, no. 1, p. 69–83

Cold-water corals (CWC), dominantly Desmophyllum pertusum (previously Lophelia pertusa), and their mounds have been in the focus of marine research during the last two decades; however, little is known about the mound-forming capacity of other CWC species. Here, we present new 230Th/U age constraints of the relatively rarely studied framework-building CWC Solenosmilia variabilis from a mound...

Université de Fribourg

Constraining the formation of authigenic carbonates in a seepage-affected cold-water coral mound by lipid biomarkers

Feenstra, Eline Juliette ; Birgel, Daniel ; Heindel, Katrin ; Wehrmann, Laura M. ; Jaramillo‐Vogel, David ; Grobéty, Bernard ; Frank, Norbert ; Hancock, Leanne G. ; Van Rooij, David ; Peckmann, Jörn ; Foubert, Anneleen

In: Geobiology, 2020, vol. 18, no. 2, p. 185–206

Cold‐water coral (CWC) mounds are build‐ups comprised of coral‐dominated intervals alternating with a mixed carbonate‐siliciclastic matrix. At some locations, CWC mounds are influenced by methane seepage, but the impact of methane on CWC mounds is poorly understood. To constrain the potential impact of methane on CWC mound growth, lipid biomarker investigations were combined with...

Université de Fribourg

Epibenthos dynamics and environmental fluctuations in two contrasting polar carbonate factories (Mosselbukta and Bjørnøy-banken, svalbard)

Wisshak, Max ; Neumann, Hermann ; Rüggeberg, Andres ; Büscher, Janina V. ; Linke, Peter ; Raddatz, Jacek

In: Frontiers in Marine Science, 2019, vol. 6, p. -

The Arctic Svalbard Archipelago hosts the world’s northernmost cold-water ‘carbonate factories’ thriving here despite of presumably unfavourable environmental conditions and extreme seasonality. Two contrasting sites of intense biogenic carbonate production, the rhodolith beds in Mosselbukta in the north of the archipelago and the barnacle-mollusc dominated carbonate sediments...

Université de Fribourg

Environmental and biological controls on Na∕Ca ratios in scleractinian cold-water corals

Schleinkofer, Nicolai ; Raddatz, Jacek ; Freiwald, André ; Evans, David ; Beuck, Lydia ; Rüggeberg, Andres ; Liebetrau, Volker

In: Biogeosciences, 2019, vol. 16, no. 18, p. 3565–3582

Here we present a comprehensive attempt to correlate aragonitic Na∕Ca ratios from Desmophyllum pertusum (formerly known as Lophelia pertusa), Madrepora oculata and a caryophylliid cold-water coral (CWC) species with different seawater parameters such as temperature, salinity and pH. Living CWC specimens were collected from 16 different locations and analyzed for their Na∕Ca ratios using...

Université de Fribourg

Boron isotope composition of the cold-water coral Lophelia pertusa along the Norwegian margin: Zooming into a potential pH-proxy by combining bulk and high-resolution approaches

Jurikova, Hana ; Liebetrau, Volker ; Raddatz, Jacek ; Fietzke, Jan ; Trotter, Julie ; Rocholl, Alexander ; Krause, Stefan ; Mc Culloch, Malcolm ; Rüggeber, Andres ; Eisenhauer, Anton

In: Chemical Geology, 2019, vol. 513, p. 143–152

High-latitude cold-water coral reefs are particularly vulnerable to climate change due to enhanced CO2 uptake in these regions. To evaluate their physiological functioning and potential application as pH archives, we retrieved both recent and fossil samples of Lophelia pertusa along the Norwegian margin from Oslofjord (59°N), over to Trondheimsfjord, Sula and Lopphavet (70.6°N). Boron...

Université de Fribourg

The Malpaisillo Formation: A sequence of explosive eruptions in the mid to late Pleistocene (Nicaragua, Central America)

Stoppa, Line ; Kutterolf, Steffen ; Rausch, Juanita ; Grobéty, Bernard ; Pettke, Thomas ; Wang, Kuo-Lung ; Hemming, Sidney

In: Journal of Volcanology and Geothermal Research, 2018, vol. 359, p. 47–67

The subduction-related volcanic front in Nicaragua consists of the Tertiary “Coyol” member in the eastern highlands and the Quaternary to recent volcanic arc within the Nicaraguan depression. Although the Holocene to recent explosive volcanism has been studied extensively no detailed work has been done on the products of explosive volcanism from Quaternary volcanic complexes comprising...