Low Energy
Alluvial Deposits from the Upper Cretaceous Prince Creek Formation, National
Petroleum Reserve,
Flaig, Peter P.1, Paul J.
McCarthy2, Erik Brandlen1, Anthony R. Fiorillo3
(1) University of Alaska-Fairbanks, Fairbanks, AK (2) University of Alaska,
Fairbanks, AK (3) Museum of Nature and Science, Dallas,
The Upper Cretaceous Prince Creek
Formation crops out along the
Most channel sandbodies are 1 to 3 m
thick, single story, very fine-to fine-grained, trough cross-laminated and/or
rippled, and frequently contain carbonized root traces and siderite
concretions. Finer-grained sandbodies occur either as small, thin, ribbon-like
channels surrounded by overbank fines, or as more extensive sheet-like sands
with lateral accretion surfaces. Ribbon sandbodies are interpreted as
non-migrating anastomosed channel fills while sheet sandbodies display a more
meandering character.
Rare, multi-story medium-to
coarse-grained sheet sandstones up to 7 m thick are also present within the
Prince Creek Formation. Coarser-grained sandbodies are dominated by lateral
accretion and contain mud rip-up clasts, trough cross-laminations, silicified
or carbonized logs, and localized pebble lags. Large dinosaur bones are also
found rarely within channel lag deposits. Medium-to coarse-grained sandbodies
are highly localized and restricted in area. Multi-story channel sandbodies
record the highest energy flows within the Prince Creek, and probably represent
meandering trunk channels within this multi-channeled alluvial system.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California