O.S. Al-Ja’aidi, B. C. Kneller, and W. D. McCaffrey
Department of Earth Sciences, University of Leeds, Leeds LS2 9JT, West Yorkshire, UK.
(e-mail : ossj99@yahoo.com)
Pre-existing seafloor topography and flow efficiency play a major role in governing the location and geometry of sandstone deposited from turbidity currents. Flow efficiency in turbidity currents is controlled by several factors, slope and calibre of sediment supply (i.e sand rich flows vs. mixed grain flows). In flows of higher efficiency, the transport phase is prolonged, thus elongating the deposit or displacing it distally. Determining flow efficiency can thus be important when predicting where the sand is likely to be deposited.
To enhance our understanding of this phenomenon we illustrate two sets of experiments in which turbidity currents were released via a lock exchange mechanism and then allowed to interact with topography. In the second set of experiments we demonstrate the effect of varying flow efficiency and its role in sand deposition. These can be used to develop an insight into the behaviour of real systems both at outcrop and in the subsurface.
