Plate 7

Sample Depth: 8908.0 ft

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A.	Overview of moderately porous dolomite characterized by a much coarser texture that shallower dolomites in this study. Euhedral-to-subhedral, finely crystalnne, sucrosic dolospar dominates texture and overprints nearly all of the original limesrotie allochens and matrix, A few remnants of dolomitized pelmatozoan fragments represent the only framework grains here. Void at center left is filled with coarsely crystalline, cleaner dolomite, and anydrite with minor halite are also important pore fillings here (though not shown). Plane-polarized light. (40x)
B.	In the same view as above, a different light source highlights typical porosity distribution. Loosely packed dolomite rhombs create intercystalline porosity, which is the most abundant pore type overall and is visible throughout this view. Sizes of intercrystalline pores we variable, ranging from approximately 10u up to l00u. Interconnectivity of intercrystalline pores is enhanced by numerous, variably oriented open microfractures (arrows). Reflected ultraviolet light with rhodamine filter. (40x)
C.	Low-magnification view illustrates one of many filled fractures encountered in this sample. Highly birefringent void- and fracture-filling mineral is coarse anhydrite. In areas labeled h, an isotropic mineral (tentatively identifed as halite) partially replaces anhydrite fill. Also note relative uniformity of dolomite crystal size and the existence of several open microfractures (magenta) both in matrix axid cross-cutting filled fracture at center. Crossed nicols. (20x)
D.	Detail of dolomite texture shows generally euhedral dolomite that is both replacive and pore filling. Replacive dolomite is characteristically "dirtier", especially at the center of the rhomb, with cleaner rims; in contrast, pore-filling dolomite (center) is entirely clean and more coarsely crystalline. Also note trace pyrite (black) filling pores at bottom of view. Plane-polarized light. (100x)