U.S. Geological Survey Open-File Report 03-040
Figure 3

Figure 3.  Schematic summary of inferred depositional sequence sets in Beaufortian strata of NPRA.  A. Proximal (~north) to distal (~south) cross section schematically illustrating stratigraphic relationships among four Beaufortian depositional sequence sets, showing general aspects of internal stratal geometry.  Note that LCU bevels Beaufortian strata northward to a zero edge on the Barrow Arch.  Selected wells are shown in positions relative to locations where they penetrate Beaufortian sequence sets, and dots on wells represent approximate stratigraphic positions of cores used in this study.                         B.  Chronostratigraphic depiction of Beaufortian sequence sets.  Shown in parentheses are stratigraphic names widely applied to strata that are approximate age-equivalents of the four Beaufortian sequence sets.  Names in italics show approximate positions of sandstones known to be reservoirs in some cases.  Vertical lines denote time gaps between Beaufortian sequence sets.  Note scale change near center of diagram.  Time scale is that compiled by Haq and others  (1988).