Recent to young fossil carbonate mounds build-up mainly by cold-water corals (predominantly the framework forming ahermatypic corals Lophelia pertusa and Madrepora oculata) occur from northern Norway to the Gulf of Cadiz but also in the Mediterranean regions (Alboran Sea). Recent research activities resulted in the coring of new discovered cold-water coral mounds in the Gulf of Cadiz (Moroccan margin) and the Alboran Sea (Melilla Mound Province). This study aims to characterize in detail the paleo-environmental record registered in those cores through detailed sedimentological and facies analyses (CT-scanning, core logging, laser particle size-analyses, detailed core descriptions, organic matter characterization) and/or paleo-environmental proxy analyses (isotopic analyses on cold-water coral fragments or other macrofauna to reconstruct paleo-environmental and paleo-climatological conditions, microfacies analyses, stable isotopes).

Cold-water coral carbonate mounds are subject to a whole range of early diagenetic processes. Aragonitic cold-water coral skeletons dissolve and authigenic carbonates precipitate due to methane release, both overprinting the primary environmental record. This study will focus on the better understanding of early diagenetic imprints in cores available from cold-water coral carbonate mounds in the Gulf of Cadiz (Pen Duick Escarpment, Moroccan margin). Detailed thin section observations (petrography and cathodoluminescence), micro-CT-scanning, elemental analyses, XRD-analyses, stable isotopic analyses and SEM-work will help in characterizing the diagenetic phases. Students will be involved in lab-experiments simulating methane release in cold-water coral carbonate mounds. Pending on the interest of the student different regions of interests can be included.

Recent and sub-recent tufa deposits are outcropping at several locations in the neighborhood of Fribourg. The proposed study aims to map the different facies along the different tufa outcrops (La Tuffière). After initial fieldwork, the different tufa facies will be studied in detail through standard petrographical microscopy, fluorescence microscopy and SEM (Scanning Electron Microscopy). In-situ precipitation experiments may be envisaged on the recent deposits exposed in the Gotteron valley (Fribourg). After discussion with the students, research interest can be tuned. This project will involve fieldwork and mapping in the neighbourhood of Fribourg.

Hot springs are continental environments were warm (up to 85°C) fluids come at the surface, degas CO2 and deposit carbonate minerals at very high rates. This commonly happens in the presence of microorganisms. They form extra-ordinary, well-laminated deposits that are thought to reflect changes in spring dynamics, microbial community and environmental conditions (T, water composition, flow rate, light). The central question is how laminated spring deposits build up in different downstream environments and what do the different laminae tell us? This project will involve field work (Edipsos island, Greece) to monitor in-situ carbonate deposition and water chemistry parameters throughout the day and the night. In the lab, microscopy, nCT imaging together with mineralogical and geochemical analyses can be used to characterize the fresh carbonate precipitates (image below). Depending on your interest, we can also set up lab experiments where a part of the natural spring environment is ‘re-built’ to do controlled experiments of carbonate precipitation rates and early diagenesis in the presence/absence of a biofilm.  

Pleistocene warm-water coral species and surrounding carbonate samples are available from different coral terraces along the basis of the Ethiopian scarp and Danakil Alps (NE Ethiopia). The coral deposits are surrounded by gypsum deposits. This study aims to perform some microfacies analyses on the collected carbonate samples (thin section analysis) and geochemistry (U/Th dating on coral fragments and stable isotopes on the collected carbonate samples) in order to recognize some major transgressive cycles within this region. When framed in an MSc-study, the student will participate to one of the field expeditions in the Danakil Depression (Ethiopia).

Stromatolitic carbonate build-ups from the Namibe Basin (SW Angola) are currently sampled and thoroughly studied. The proposed study aims to understand better the diagenesis in this setting through further SEM analysis, Sr analysis, stable isotopic analysis and potential fluid inclusions. This project will be carried out in close collaboration with Industry (TOTAL S.A.).

The Danakil depression is a 300 km long rift valley being part of the Afar triple junction in Ethiopia and witnessing an ocean at birth. This Bachelor project will focus on the description of drill cuttings from a 250 m deep well composed of a mixed siliciclastic-carbonate rich environment intercalated withevaporites. A chronostratigraphic framework and detailed litholog will be created combining different methods – such as thin-section analysis, XRD analyses and combined radiocarbon - U/Th dating. The dataset will be interpreted in terms of palaeo-environments and placed into a paleogeographic context. The student will learn numerous indispensable tools in Sedimentology and spread his knowledge in Basin and Sedimentary Geology. This Bachelor thesis could be extended to a Master thesis using other wells and seismic data for an interpretation at basin scale.

This research project at the lakeside of Great Salt Lake has a focus on tufa mounds and spring deposits located along the 12000 to 13000 year old paleoshoreline of the Great Salt Lake. The paleoshoreline is characterized by shallow biostromes (stromatolites and thrombolites). The depositional system provides the opportunity to study the continuum from spring-sourced tufa (with possible bio-influenced precipitation) to bio-induced lacustrine thrombolite or stromatolite buildups. The student will be involved in the detailed mapping of the facies and the delineation of the geobodies to establish physical relationships between the tufamounds and the biostromes. One core area will be mapped in detail during fieldwork and the student will participate in the field expedition to Great Salt Lake.