Page 461 - Carbonate Facies in Geologic History

450

Plate XX. Encrusting Bindstone

(A) Masses of tubular calcitornellid foraminifera from capping rock of a lower
mound stage buried in the interior of a Late Pennsylvanian Virgil ian algal plate
accumulation. See Chapter VI. Sample C-IO of Yucca mound comes from north
of State Highway 83, at the mouth of Dry Canyon, Sacramento Mountains, New
Mexico (see Fig. VI-tO). Photograph is courtesy of D.F. Toomey, University of
Texas Permian Basin. Thin section, xIS

(B) Masses of probable foraminifera Renalcis interlaminated with stromato-
lite from Late Devonian of Alberta. This encrusting organism is common in the
Late Devonian of Australia (see Chapter IV) and in Cambrian beds in several
parts of the world. Its biological affinity is unknown but its similarity to tubular
encrusting forams of Late Paleozoic to Triassic age is considerable; and it occu-
pies a similar habitat, characteristically capping mounds and reefs and forming an
encrusting type of boundstone. Photograph is courtesy lE. Klovan, University of
Calgary, Alberta, Canada. Thin section, x 25