Anhydrite Fabrics

A wide range of anhydrite fabrics are present in the Khuff succession. The various forms provide significant depositional and diagenetic environmental information. "Pacman" anhydrite illustrated below documents replacive anhydrite growth in dolomite and limestone from corrosive saline solutions. What is particularly interesting is the nodular shape of the anhydrite, something that is generally associated with anhydrite thought to signify a displacive origin. The importance of this form of anhydrite growth in the formation of more massive anhydrite sections in the Khuff remains to be evaluated. Furthermore, its interpretive significance in general requires further investigation as noted in our ongoing Research page.

Felted "pacman" anhydrite exhibs carbonate rim (stained for calcite) partially replaced by anhydrite laths.

These two images show details of the attacked carbonate rim in plane-polarized (left) and plane cross-polarized (right) transmitted light

Mudstone with coarsely crystalline carbonate rim developed around felted "pacman" anhydrite. Note white areas within carbonate rim and corred carbonate crystal margins adjacent to anhydrite core. Plane-polarized transmitted light.