Distribution of
Hyperpycnal Deposits in the Delta Front of Cretaceous
Panther Tongue
Olariu, Cornel1,
Ron J. Steel1 (1)
River-derived turbidity flows have been
recognized as a process that transfers significant volume of sand from rivers
to basin. We document a series of beds from Cretaceous Panther Tongue sandstone
in
We distinguished four main
sub-environments: subaqueous channel, mouth bar,
proximal delta front, distal delta front. The data collected show that channel
and mouth bar, with erosional surfaces and scours,
commonly represent bypass areas for the hyperpycnal
flows. Proximal and distal delta-front environments, with alternation of mud
and sand beds, represent depositional areas for such flows. Some of the
proximal delta-front beds are coarser than those from the overlying mouth-bar
deposits suggesting that higher energy flows bypassed mouth-bar areas and
deposited coarser sediments distally.
The delta-front clinoforms
dip south and are relatively steep for such fine sand, suggesting high
discharge and depositional rates. Our results suggest that despite high
discharge and common hyperpycnal flow in the Panther
Tongue system the underflows did not travel too far into the basin. To have a
longer bypass area into deeper water a longer or steeper delta-front gradient
to sustain the hyperpycnal flow is required.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California