Abstract

I will present two examples of deformation found in deep-marine deposits laid down by turbulent flows, both of which can tell us a little about the nature of the flows. In the first part of the talk, I shall describe field examples of metre-scale folded rafts that are often found encased within the deposits. These have recently been interpreted as an important diagnostic feature of hybrid event beds, a particular complex type of deep-marine deposit. I will discuss an alternative hypothesis based on new field data suggesting that the raft transport direction is transverse to the turbidity current flow direction. In the second part of the talk I will describe small-scale folds, termed convolute lamination, that may represent Rayleigh Taylor instability combined with current shear. Supporting ancient and modern field evidence will be presented.