Polished rock slab showing quartz- and calcite-replaced evaporites in
mudstones. Dark color of quartz crystals, in particular, reflects the abundance of hydrocarbon
inclusions. 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. Length of slab = 12 cm.
© Peter A. Scholle, 1999