Page 314 - Carbonate Facies in Geologic History

Summary 301

SASIC . "'AN.

25.50'!'oglobu la(
,.,omotopoto;dl

Fig.X-16. Generalized facies of a typical Duperow (Late Devonian) cycle in the Williston
basin of North Dakota and southern Canada. Note stromatoporoid banks and brown nor-
mal marine wackestone facies to north and restricted marine lime mudstone and wackestone
south of the heavy dashed line. Evaporite at top of cycle increases to the south in proportion
to carbonate but suddenly disappears owing to subsequent solution. The exact configuration
of the southern land area is unknown. Its presence is inferred from increased terrigenous
content and complete dolomitization of the Duperow in the southern Montana-Wyoming
area. After Wilson (1967 b)

come from these strata. Regional facies (Fig. X-17) are mapped by Meissner (1972)
and sedimentary cycles were described by Meissner (1972), Chuber and Pusey
(1972), and Lucia (1972). The latter paper on shoreline carbonate sedimentation
offers useful descriptions and illustration of the Clear Fork cycles on the Central
Basin platform. Table X-2 is from Lucia (1972, p. 169).

Summary

Numerous other examples oflime mud-sabkha cycles occur in shallow basins and
adjoining shelves in North America: e.g., the Ordovician and Silurian Williston
basin strata well described by Roehl (1967), the EI Paso Ellenburger-Arbuckle
groups of southwestern U.S.A. and the Glen Rose beds of the Texas craton. A