Measuring and modelling stacking patterns in turbidite sequences

 

PhD Candidate: Javier Lopez-Cabrera

Supervisor: Dr Tom Manzocchi, Prof. Peter Haughton

Funded by: This PhD is supported in part by a research grant from Science Foundation Ireland (SFI) and is co-funded under the European Regional Development Fund and by PIPCO RSG and its member companies

Abstract:

Compensational stacking is known as the tendency of younger sedimentary elements to avoid being deposited directly above older elements, but instead to be offset laterally and be deposited in topographic lows (Straub et al., 2009). It has been recognized in a large range of different depositional environments including delta, alluvial, fluvial and deepwater systems (Pederson et al., 2015; Prelat et al., 2009; Trampush et al., 2017; Straub et al., 2009; Straub and Pyles, 2012). Studying this phenomenon and its geometry is critical: conventional object-based modelling is very poor at reproducing compensational stacking. Additionally, compensation can have important implications in reservoir modelling since inter-element connectivity is in part controlled by the extent to which the elements are stacked compensationally (Manzocchi, et al., 2007).

This PhD project will focus on new ways to quantitatively measure compensational stacking. Sedimentological, structural, mathematical analysis and 2D numerical modelling will be used to constrain in cross-section the geometrical patterns associated with compensational stacking and inter-element connectivity: 2D/1D outcrop characterisation will be performed in order to recognize stacking patterns and its hierarchical organisation. Real geological data and numerical models will be used. Forward modelling results summarising 1D bed distribution statistics as a function of stacking patterns derived from models created with the compression algorithm and standard object-based modelling will be studied. Modelling software is expected to be developed, as well as new equations and tools that allow us to have a better understanding of compensational stacking. This outcome will improve our understanding of these sequences and will have practical implications in reservoir modelling.

 

References:

Manzocchi, T., Walsh, J.J., Tomasso, M., Strand, J., Childs, C., Haughton, P.D.W. 2007. Static and dynamic connectivity in bed-scale models of faulted and unfaulted turbidites. In: Jolley, S.J., Barr, D., Walsh, J.J., Knipe, R.J. Structurally Complex Reservoirs. Geological Society, London Special Publications. 292, 309-336.

Pederson, C.A., Santi, P.M., Pyles, D.R. 2015. Relating the compensational stacking of debris-flow fans to characteristics of their underlying stratigraphy: implications for geologic hazard assessment and mitigation. Geomorphology. 248, 47-56.

Prelat, A., Hodgson, D.M., Flint, S.S. 2009. Evolution, architecture and hierarchy of distributary deep-water deposits: a high-resolution outcrop investigation from the Permian Karoo Basin, South Africa. Sedimentology, 56, 2132-2154.

Straub, K.M., Paola, C., Mohrig D., Wolinsky, M.A., George, T. 2009. Compensational stacking of channelized sedimentary deposits. Journal of Sedimentary Research. 79, 673-688.

Straub, K.M., Pyles, D.R. 2012. Quantifying the hierarchical organization of compensation in submarine fans using surface statistics. Journal of Sedimentary Research, 82, 899-898.

Trampush, S.E., Hajek, E.A., Straub, K.M., Chamberlin, E.P. 2017. Identifying autogenic sedimentation in fluvial-deltaic stratigraphy: Evaluating the effect of outcrop-quality data on the compensation statistic. Journal of Geophysical Research, Earth Surface. 122, 91-113.