RESEARCH

I am interested in the life cycle of sedimentary carbonates – from precipitation (abiotic, biologically induced and biologically controlled) through deposition to early diagenesis. Initially, my group was working with deep lacustrine settings, now we do make excursions into the shallows or on land. Depending on the environment, depositional processes leave a characteristic imprint on carbonate chemistry. We start with carbonate chemistry and are working our way through to reconstruct environmental changes. Unravelling the primary and/or secondary nature of the isotopic (d18O, d13C) and elemental (Mg/Ca, Sr/Ca) signal of different carbonate components is a fascinating challange which involves geochemical and petrographical approach often combined with ecological and (micro)facies analyses.

 

Lake Van carbonates

Lake Van

Sedimentary record of Lake Van, the world’s largest soda lake, spans the last 600 ka and documents climatic and tectonic evolution of the region. Available data clearly show the transition from a freshwater to alkaline lake at ca. 450 ka and a strong influence of glacial/interglacial cycles ever since. Set in the robust climatic context, lake Van carbonates and microfossil assemblages are an excellent material for testing the strengths and limitations of carbonate-based hydrological proxies.

 

Application of land snails’ shells for environmental reconstruction

snails

Land snails’ shells constitute a valuable source of environmental information, especially in arid regions where other carbonate material are scarce. The oxygen isotope signal of the shell is related to temperature and a source and amount of moisture, while the carbon isotope signal reflects the dietary control. My team analyses shells from Europe and Africa and systematically test different methodological approaches in order to obtain reliable and robust results.

 

Paleolakes in Morocco

01_amellago_q1

African Humid Period (AFH, ca. 14 to 5 ka BP) is an excellent example of precessional forcing on lower latitudes. Much is already know about the Termination of AFH, considerably less about its onset. We are studying paleo-lacustrine and –palustrine sequences from Morocco (NW Africa), combining geomorphological, sedimentological and geochemical proxies with 14C dating. Out project aims not only at compelling documentation of hydrological changes at a regional scale but also represents an integrated approach to better understand palustrine depositional environment.

 

 

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