17. Chalky limestone, like 26, with 0.1-foot-thick shaly zone 0.4 foot below top; limonite nodules occur at base of unit; limonite-filled threadlike burrow? structures in lower part; FOSSILS - Inoceramus deformis (whole and fragmentary), Ostrea congesta. 1.6 16. Chalky limestone, like 26, shaly at top and base, limonite nodules common at base; FOSSILS - Inoceramus deformis (whole and fragmentary), Ostrea congesta, Serpula sp. 2.9 15. Chalk, weathered yellowish gray to moderate yellowish brown, middle part shaly and with many irregular-shaped chalk-filled burrow structures; pyrite- and limonite-filled rodlike burrow structures; FOSSILS - Ino- ceramus deformis (mostly whole), Ostrea congesta 1.4 14. Chalky limestone, weathered pale yellowish gray to pale grayish orange or nearly white, lower 1 foot mottled with medium gray, with scattered blebs of pyrite most of which is partly limonitized, and vertical pyrite- filled rodlike burrow structures; FOSSILS - Inoceramus deformis (whole and fragmentary), Ostrea congesta. 2.9 13. Shaly chalk, olive-gray to light-olive-gray, with many horizontal chalk- filled burrow structures; FOSSILS - Inoceramus deformis (mostly frag- mentary) 0.3 12. Chalky limestone, light-olive-gray with olive-gray shaly zone at re- entrant near top, many horizontal chalk-filled burrow structures; FOSSILS - Inoceramus deformis, (whole and fragmentary), Ostrea congesta 2.3 11. Shaly chalk, olive-gray. 0.1 10. Chalky limestone, weathered pale yellowish gray to grayish yellow, in part stained dark yellowish orange by limonite, lichen-covered where measured, upper part shaly with many irregular-shaped chalk-filled burrow structures; FOSSILS - Inoceramus deformis (whole and fragmentary), Ostrea congesta. 3.7 9. Shaly chalk, olive-gray. 0.1 8. Chalky limestone, like 14, limonite blebs scattered throughout, with irregular-shaped chalk-filled burrow structures, especially near middle and top of unit; FOSSILS - Inoceramus deformis (whole and fragmentary), Ostrea congesta. 4.3 7. Chalky limestone, weathered yellowish gray, shaly at base and top, limonite blebs common near middle of unit, local manganese dendrites, many irregular-shaped chalk-filled burrow structures; FOSSILS - Inoceramus deformis (whole and fragmentary), Ostrea congesta. 5.5 6. Chalky limestone, medium-gray to light-olive-gray weathering grayish orange and locally dark yellowish orange, some lichens, uppermost part shaly, base of bed cavernous, sparse limonite nodules near base, many irregular-shaped calcite-filled burrow structures; unit in part very thinly laminated and possibly cross-laminated, with scattered very thin lenses of skeletal limestone; FOSSILS - Inoceramus deformis (whole and fragmentary), Ostrea congesta. 4.5 5. Chalky limestone, like 14, upper 1.3 feet light olive gray, some lichen cover, sparse limonite and pyrite nodules near top; all with irregular- shaped chalk-filled burrow structures, especially in upper 1.3 feet; FOSSILS - Inoceramus deformis (mostly fragmentary), Ostrea congesta.. 4.0 4. Shaly chalk, dark-gray weathering light olive gray, forms prominent re-entrant. 0.1 3. Chalky limestone, weathered pale grayish orange to grayish orange, with limonite nodules in zone near middle; unit contains scattered irregular- shaped chalk-filled burrow structures and numerous vertical limonite- filled threadlike burrow structures; FOSSILS - Ostrea congesta 1.6 2. Chalky limestone, like 14, some lichen cover; silty, especially at base; scattered limonite-filled rodlike burrow structures, many irregular- shaped chalk-filled burrow structures; FOSSILS - Ostrea congesta (frag- ments) 1.9 Total thickness of Fort Hays Limestone Member 71.9 67