462
Sequence Stratigraphy
Fig. 13.9. Sharp, and probably erosional sequence boundary between the Blackhawk Formation and overlying
Castlegate Sandstone at Price Canyon, Utah, indicated by arrow. (Miall 1993; Olsen et al. 1995; Yoshida et al., in press}
JOES
VALLEY
PRICE
CANYON
SUNNYSIDE c���
TRAll.
CANYON
TUSHER
CANYON
THOMPSON
CANYON
ft
m
1
' oo l' o o I
HORIZONTAL
I
I
SCALE
I
I
I
VERTICAL
200
SCALE
IOO
-- 0
0
0
0
10
20 km
- - -- Type 1 Sequence Boundary
- - -- Migrating Zone A I Zone B Boundary
Fig. 13.10. Schematic synthesis of the sequence stratigraphy of the upper Mesa Verde Group in the Book Cliffs,
Utah, showing the interpreted migration of the zone A/
zone B boundary ofPosamentier and Allen (1993), and the
distribution of type 1 sequence boundaries. This architecture is interpreted as the product of the superimposition of
Paradox Basin
Margin
high�frequency ( < 1 million years cyclicity) base� level
changes of probable tectonic origin on a long-term (5
million years) cycle of flexural subsidence. Additional
stratigraphic details of the Castlegate Sandstone and
related units are shown in Fig. 9.18. (Yoshida et al., in
press)