SEDIMENTOLOGY OF THE BRUSHY BASIN MEMBER OF THE MORRISON FORMATION ASSOCIATED WITH THE AARON SCOTT DINOSAUR SITE (JURASSIC), FERRON, UTAH

The Aaron Scott Site has been described as a delta deposit along an inland lake margin where numerous animals congregated during a drought. Sedimentology of the Aaron Scott Site compared to the remainder of the upper Brushy Basin Member indicates that while the Brushy Basin Member is dominanted by soil horizons, the Aaron Scott Site does not exhibit soil features, but rather fluvial-deltaic features. Although all samples were dominantly quartz-silt with calcite cementation, the Aaron Scott Site lacks root traces and other pedogenic features seen in the upper Brushy Basin. The Aaron Scott Site also exhibits current orientation of the bones in the deposit and clay rip-up clasts, suggesting a fluvial influence. The sedimentology of the site supports a fluvial-deltaic deposit along a large lake. Over time the lake filled up and the area became dominated by meandering streams with large arid floodplains where soils were produced.