Process Stratigraphy — Physics-Based Stratigraphic Predictions Applied to Sandy-Steep Submarine Fan Deposits; Example of the Youngest Late Pleistocene Lobe in the Golo Submarine Fan System, East Corsica

Abstract

Abstract

Improved predictions of clastic reservoir architecture might be achieved by quantitatively constraining interpretations using process-based workflows combined with analog-based stratigraphic concepts. This process-based approach combines experimental, numerical, analytical, and field studies over a wide range of scales to constrain the finest reservoir architecture and improve conectivity predictions. Recent tank experiments of steep sandy submarine fans have related unique patterns of channel extension, lobe stacking and channel backfill to morphodynamic interactions related to hydraulic jumps. Definitive testing of these hypotheses can only be carried out using high-resolution seismic (e.g. close to bed scale resolution) coupled with core data.

The example presented here is the youngest late Pleistocene lobe in the Golo submarine fan system, East Corsica. This ‘distributary channel-lobe complex’ was traversed by a closely spaced grid of multi-channel sparker 2-D lines with a vertical resolution of two to three meters allowing the decomposition of the stratigraphy into its fundamental building blocks. Lobe elements comprised of stacked sandy-leveed channel elements are very erosive at the channel-lobe-transition and evolve into subtle aggrading channel geometries terminated by short unconfined terminal lobes. They consist of beds or bed-sets stacked in a generally retreating pattern recognized in isopach maps and the aggrading/retrograding filling of the incised channels. These observations suggest that real sandy supercritical fans like Golo prograde through cycles of channel extension and backfilling.

As in the experiments, the deepest scour upstream of the channel-lobe transition is backfilled by upstream dipping strata (backsets) in a complex fashion. This observation combined with steeper backsets associated with bedforms identified in earlier studies, suggests that the Golo fan is deposited by turbidity flows in the supercritical regime. A long core through the youngest southern lobe complex enables us to link bedform successions with surfaces interpreted from the seismic.

AAPG Datapages/Search and Discovery Article #90260 © 2016 AAPG/SEG International Conference & Exhibition, Cancun, Mexico, September 6-9, 2016