ICON-SE · Ichnological analysis of core and outcrop contourite facies: scientific and economic implications

Ichnological analysis of core and outcrop contourite facies: scientific and economic implications

Deep water dynamic causes different types of currents (e.g., internal waves, contour currents or deep-water bottom currents among others). All these currents erode and deposit sediments, generating complex depositional systems with a high interest in palaeoenvironment, palaeoceanography and hydrocarbon exploration. These deposits, are called in general terms as contourites and their study has undergone a huge development due to their abundance and importance, being considered as a very hot topic in palaeoceanography. However, they are still poorly understood and some controversial points about their recognition and differentiation from associated sediments remain unsolved. Large-scale contourites drifts can be easily identified based on seismic-reflection data, but their characterization is much more complicated when working at small-scale (outcrops or cores). For this purpose, bioturbation has been proposed as a potential criterion to differentiate contourites deposits from turbidites and hemipelagic/pelagic ones. Bioturbation was firstly considered as a diagnostic criterion as contourites and mixed systems have significant macrobenthic trace-makers activity. Moreover, during the last years, one of the most used proxies in sedimentary basin to interpret palaeoenvironmental conditions and ocean/atmosphere dynamic is the ichnological analysis. Trace fossils reflect the trace-maker behaviour, recording modifications associated to environmental changes and, consequently being a powerful tool in palaeoenvironmental and palaeoecological studies. Moreover, analysis of bioturbation is also a powerful tool for hydrocarbon exploration as trace fossils can modify porosity and permeability of sediments,affecting the potential reservoir quality. Considering the scarcity of ichnological studies in contourites, but evidencing the importance of bioturbation as a potential diagnostic criterion, the influence in porosity and permeability values and its economic interest, the ICON-SE project is focused, for the first time, on the detailed ichnological analysis of these deposits, with two main objectives: 1. Ichnological characterization of contourite deposits. 2. Determining the influence of trace fossils in hydrocarbon exploration and its economic implications. The main purpose of this project is to explore the presence of trace fossils which are commonly underestimated in their importance for the society (based on palaeoenvironmental and hydrocarbon industry applications), that they play a structural function in contourite formations and especially critical in economic implications as potential reservoirs.

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