Dolomite formation in microbial mats in Qatar's sabkhas

In this talk, I will present the results of our studies on the role of microbes in dolomite formation in a hypersaline environment. Although significant advances in our understanding of dolomite precipitation have been made, the abundance of ancient dolomitic sequences remains an enigma. Our multi-seasonal work with microbial mats in the hypersaline sabkhas of Qatar shed light on the interplay between in environmental conditions, microbial communities, and dolomite formation. We observed cyclical fluctuations in microbial community composition which shift from growing microbial mats (GMM) with oxygenic phototrophs to decaying microbial mats (DMM) which are dominated by anoxygenic phototrophs. Our findings suggest that the interplay between oxygenic and anoxygenic phototrophs is a key factor for dolomite formation.

*** invited by Stefan Peiffer & Martin Obst

• BayCEER Kolloquium Prof. Maria Dittrich