Second-day road log, from Tucumcari to Mesa Redonda, Pyramid Mountain, Ragland, and Blackwater Draw, New Mexico

Today’s trip begins by examining Mesozoic strata exposed around erosional outliers of the northern edge of the Llano Estacado in Quay County, New Mexico. STOP l at Mesa Redonda is at the type section of the Redonda Formation, the youngest Upper Triassic strata beneath the Llano Estacado. Here, we discuss the base of the Redonda Fonnation, a possible regional unconformity, and the depositional environment of the formation.

STOP 2 is at Pyramid Mountain, where, in September 1853, Jules Marcou undertook the first detailed scientific observations made by a trained geologist in New Mexico. Here, we examine the Triassic-Cretaceous section. STOP 3 at Ragland affords an excellent exposure of the Neogene Ogallala Formation. STOPS 4 and 5 are at the Blackwater Draw Museum and Blackwater Locality No. I, respectively. Here, we examine the type Clovis locality, its stratigraphy, deposition and dating.