The
Fischbein, Steven A.1,
Christopher R. Fielding2, R. Matthew Joeckel2 (1)
Nebraska Department of Environmental Quality, Lincoln, NE (2) University of
Nebraska-Lincoln, Lincoln, NE
Incised sandstone bodies in the uppermost
Pennsylvanian Admire Group in southeastern
Sequence boundaries correlated in outcrop
to areas where sandstone bodies are absent but paleosols are preserved at the
equivalent horizon are interpreted as correlative conformities to the sequence
boundaries. These correlations offer evidence for the regional continuity of
sequence boundaries along which further such channelized sandstone bodies may
be preserved.
Reclassification of the
“Indian Cave Sandstone” into at least four incised-valley-fills (IVF) offer
evidence of reservoirs in the high Midcontinent platform that have to date seen
only minimal investigation. These potential reservoirs are architecturally
similar to the Tonganoxie Sandstone in eastern Kansas and Morrow IVF sandstones
of eastern Colorado and western Kansas, although significantly further
up-depositional dip. Units identified as “Indian Cave Sandstone” located within
equivalent stratigraphic position but significantly down depositional dip
contain recoverable quantities of oil and gas. As such, in regions where an
uppermost Pennsylvanian subcrop is identified, and a high shelf platform
position is interpreted, incised valley fill networks are potential reservoirs
and appropriate hydrocarbon exploration targets.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California