Geobiology in Arabian Gulf sediments

PhD student Hazel Vallack races to process water samples before the sun sets over the sabkha.

Following a pilot study in Oct 2017, Sarah Greene co-led a successful sampling expedition to the sabkha west of Abu Dhabi in the United Arab Emirates in January 2019. 

The project seeks to fingerprint the drivers of marine carbonate (limestone) hardground formation – the cementation of sediments at or just below the sediment surface.

Unravelling why hardgrounds are forming in the shallow sediments of the Arabian Gulf (one of the few places where this process is actively occurring) can 1) help us interpret hardground-forming palaeoenvironments and 2) inform model predictions about the size of the subseafloor carbonate carbon sink.

The drivers of the cementation may be geological, geochemical, physical, and/or biological factors, and so the field sampling relied on an array of cross-disciplinary techniques including aqueous geochemistry, sedimentology, hydrogeology, and functional genomics. The field trip was in support of Sarah’s Bristol-based PhD student, Hazel Vallack, and was co-led by Prof. Fiona Whitaker (University of Bristol) with assistance from Dr. Stephen Lokier (Bangor University), Birmingham Earth Sciences alumnus Dr. Gordon Coy, and several colleagues at Khalifa University in Abu Dhabi.