Autogenic process change in modern deltas: lessons for the ancient - From Depositional Systems to Sedimentary Successions on the Norwegian Continental Margin - page 164

tidal-dominated or wave-dominated deltas laterally
along depositional strike.
Autogenic process change can be inferred in
ancient deltas when distinct changes in delta-front
facies character are observed in the same regressive-
transgressive cycle parasequence. The facies change
from one dominant process to another is consid-
ered to be an autogenic response of the system if the
changes are recorded over a relatively small area
but not at basin scale. It is important to distinguish
between autogenic and allogenic delta process
responses because the former are confined to parts
of a single system, whereas the latter are likely to
apply to all depositional systems in the basin. Due
to different delta morphologies and efficiency for
cross-shelf sediment transport, autogenic process
changes have implications for effective sediment
dispersal, not only across the shelf but also across
the shelf break and into deepwater areas.

sandstones, Cretaceous Ferron Sandstone, Utah [Ph.D.
thesis], University of Texas, Austin, 259 p.
Bhattacharya, J.P. and Walker, R.G. (1991) River- and
wave-dominated depositional systems of the Upper
Cretaceous Dunvegan Formation, northwestern Alberta.
Bull. Can. Petrol. Geol ., 39 , 165-191.
Bhattacharya, J.P. and Willis, B.J. (2001) Lowstand deltas in
the Frontier Formation, Powder River basin, Wyoming:
implications for sequence stratigraphic models. AAPG
Bull ., 85 , 261-294.
Burgess, P.M. and Hovius, N. (1998) Rates of delta prograda-
tion during highstands: Consequences for timing of dep-
osition in deep-marine systems. Journal of the Geological
Society , 155 , p. 217-222.
Busch, D.A. (1971) Genetic units in delta prospecting.
AAPG Bull ., 55 , 1137-1154.
Caline, B. and Huong J. (1992) New insight into the recent
evolution of the Baram Delta from satellite imagery.
Bull. Geol. Soc. Malaysia , 32 , 1-13.
Carvajal, C. and Steel, R. (2009) Shelf-edge architecture
and bypass of sand to deep water: influence of sediment
supply, sea-level and shelf-edge processes. J. Sed. Res .,
79 , 652-672.
Charvin, K., Hampson, G.J., Gallagher, K.L. and
Labourdette, R. (2010) Intra-parasequence architecture
of an interpreted asymmetrical wave-dominated delta.
Sedimentology , 57 , 760-785.
Coleman, J.M. (1988) Dynamic changes and processes in
the Mississippi River delta. Geol. Soc. Am. Bull ., 100 ,
999-1015.
Coleman, J.M. and Gagliano, S.M. (1964) Cyclic sedimen-
tation in the Mississippi River deltaic plain. Trans. Gulf
Coast Assoc. Geol. Soc ., 14 , 67-80.
Coleman, J.M. and Wright, L.D. (1975) Modern river
deltas; variability of processes and sand bodies. In:
Deltas, Models for Exploration (Ed. M.L. Broussard),
99-149.
Coleman, J.M., Roberts, H.H. and Stone, G.W. (1998) Mississippi
river delta: an overview. J. Coastal Res ., 14 , 698-716.
Dan, S., Stive, M.J.F., Walstra, D-J. and Panin, N. (2009)
Wave climate, coastal sediment budget and shoreline
changes for the Danube Delta. Mar. Geol ., 262 , 39-49.
Dewey, J. A., Jr. and Morris T.H. (2004) Geologic framework
of the lower portion of the ferron sandstone in the willow
springs wash area, Utah: facies, reservoir continuity and
the importance of recognizing allocyclic and autocyclic
processes. In: Regional to Wellbore Analog for Fluvial-
Deltaic Reservoir Modeling: The Ferron Sandstone of
Utah (Eds T.C. Chidsey, Jr., R.D. Adams and T.H. Morris),
AAPG Studies in Geology , 50 , 305-329.
Edmonds, D.A. and Slingerland, R.L. (2007) Mechanics of
river mouth bar formation: Implications for the morpho-
dynamics of delta distributary networks. J. Geophys.
Res ., 112 , F02034, doi: 10.1029/2006JF000574.
Fairbanks, R.G. (1989) A 17,000-year glacio-eustatic sea-
level record: influence of glacial melting rates on the
Younger Dryas event and deep-ocean circulation.
Nature , 342 , 637-641.
Fisher, W.L. and McGowen, J.H. (1967) Depositional sys-
tems in the Wilcox group of Texas and their relationship
to occurrence of oil and gas. Trans. Gulf Coast Assoc.
Geol. Soc ., XVII , 105-125.

ACKNOWLEDGEMENTS

I acknowledge the RioMAR Consortium sponsors
(BG, BHPBilliton, BP, Devon, ENI, Shell, Statoil,
PDVSA, Petrobras, Woodside) for their continuous
support and lively discussions during consortium
meetings. I thank associate editor John Howell and
reviewers Gary Hampson and Brian Bracken who
improved an initial version of the manuscript
through constructive comments. Ron Steel greatly
improved the clarity of the ideas and of the manu-
script through multiple discussions with the author.

REFERENCES

Ainsworth, R.B., Flint, S.S. and Howell, J.A. (2008)
Predicting coastal depositional style: influence of basin
morphology and accommodation to sediment supply
ratio within a sequence stratigraphic framework. In:
Recent Advances in Models of Siliciclastic Shallow-
Marine Stratigraphy (Eds G.J. Hampson, R.J. Steel, P.M.
Burgess and R.W. Dalrymple), SEPM Spec. Publ ., 90 ,
237-263.
Ainsworth, R.B., Vakarelov, B.K. and Nanson, R.A. (2011)
Dynamic temporal and spatial prediction of changes in
depositional processes on clastic shorelines: toward
improved subsurface uncertainty reduction and man-
agement: AAPG Bull ., 95 , 267-297.
Allen, G.P., Laurier, D. and Thouvenin, J. (1979) Étude
Sédimentologique du delta de la Mahakam: Notes et
Mémoirs . Compagnie Fraçaise des Pétroles, 15 , 156 p.
Barton, M.D. (1994) Outcrop characterization of archi-
tecture and permeability structure in fluvial-deltaic