Thin section photomicrograph (cross-polarized light) of anhydrite inclusions in megaquartz
replacement of precursor evaporite nodule in Yates Fm. Silicification preceded calcalcitization of
evaporites and apparently occurred at or near maximum burial of these units. Thus, the silicified
nodule rinds preserve both solid inclusions of evaporites, and fluid inclusions of high-salinity
brines and hydrocarbons.. Sample is from far back-reef facies of Yates Fm. in outcrops along
an ephemeral stream bank just north of Dark Canyon road, approximately 10 km west of
canyon mouth, Eddy Co., New Mexico. Long axis of photo = 0.51 mm.

© Dana Ulmer-Scholle, 1999

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