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Plate XXV. Permo-Triassic Cavity Fillings in Micrite
and Boundstone

(A) Cavity in "reef fabric" in Triassic (Ladinian) Dolomite showing laminate
encrusting boundstone (dark) with several stages of cavity filling: (1) light-colored,
irregular and open laminae, (2) centripetally oriented sparry calcite, and
(3) second generation of lighter calcite. Sample MS-17 is from a Cipit (exotic)
block on the northeast Rosszahne trail at the edge of Seiseralm, northern Italy.
Thin section, x 10
(B) Cavity in Permian Reef Complex of the Guadalupe Mountains, New
Mexico; facies Pm-5 of Chapter VIII. A micritic matrix on the right and left edges
of the photograph is typical of much of the "reef'. This matrix is covered by
encrusting bryozoan, tubular foraminifera and finally an irregular lamina of pos-
sible algal origin. This encrusting growth has surrounded a few cavities in the
boundstone, the largest of which contains some internal sediment. The geopetal
sediment indicates that the top is to the right. The major cavity is lined with dark
micrite on both sides. The cavity is filled with several generations of fine, gray
druse. A later generation of coarser druse appears at the lower left corner. Sample
AAF-12 from Pinery Trail above Guadalupe Pass, Culberson County, Texas.
Thin section, x 16