Geometry determination of channel-fill deposit induced by turbidity current: A study from an outcrop analogue
Channel system produced by turbidity current has been proved as one of the most prominent hydrocarbon reservoirs. Geoscientists find many challenges to characterize and to predict the geometry of the turbiditic deposit because of their complexities, diversities, and outcrop scarcities. Thus the objective of this research is to understand the geometrical characteristic of the turbiditic channel and how it is generated by studying its outcrop as an analogue for subsurface hydrocarbon reservoir. This study discusses geometry determination and paleogeographical environment from the outcrop. From the field observation, we found that the turbidite facies is encased in a muddy deposit of other associated facies. The turbidite facies composed of interbedded coarse-grained sandstones and very coarse-grained in the lower part with planar and cross-bedding sedimentary structure. The base of this facies is sharp or locally show erosional surface with burrows commonly observed in the middle or upper part of the facies. The dimension of this package is 360 cm thick with overall fining-upward pattern in the uppermost 100 cm. The overall geometry of the outcrop represents a lens of channel-fill deposit induced by the turbidity current. The expected initial environment of this outcrop that we propose is on a deep water steeper slope with smoother relief and without any confining boundary. Further study on petrography, biostratigraphy, and forward modeling will be needed in the future to be able to replicate turbidity process in deep water slope environment.