Page 457 - Carbonate Facies in Geologic History

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Plate XVIII. Devonian Stromatoporoid and Stromatactoid Struc-
ture

(A) Tabular stromatoporoid in micrite from a mound (bioherm) in Frasnian strata
of the Dinant basin, Belgium: bindstone of Embry and Klovan (1971), standard
microfacies 7 and facies 6D of Chapter IV. Such forms occur intergrown with
sheet-like masses of the tabulate coral Alveolites and are more common in the
lower, quieter water portion of the mound. Photograph and preparation courtesy
ofF.R. Allcorn, Tenneco, Houston, Texas. Polished slab with acetate peel affixed,
x 1

(B) Stromatactoid structure. White areas are of void-filling coarse calcite. The
digitate top and even base are well displayed. Such cavities in micrite matrix are
common in lime mud mounds and are regularly developed in en echelon sheet-
like patterns in Lower Carboniferous and Devonian bioherms in Europe (see
Chapter V). This sample is from the Frasnian Marbre Rouge, Carriere de Croi-
settes, Dinant Basin, Belgium. Preparation and photograph courtesy of F.R.
Allcorn of Tenneco, Houston, Texas. Polished slab with acetate peel affixed,
x 11/2