PEDREGOSO, Formation

TERTIARY (middle Oligocene)

State of Falcón, Venezuela

Author of name: Lenzinger, Messmann and Senn, 1927 (private report).

Original reference: A. Senn, 1935, p. 71.

Original description: ibid.

Pedregoso was proposed for outcrops in Rio Mitare where the San Luis limestone has thinned to a few massive beds interbedded with calcareous sandstones and shales. The formation rests conformably on Pecaya shales and is overlain by Agua Clara shales. It ts one of the upper formations in the Mitare group (see) of Pantin and of Mencher et al. (1951); although Senn (1940, p. 1580) had no longer included it in his correlation table.

Petroleum geologists now recognize this formation as a lateral transition between the San Luis reef and predominantly sandy formations which have been given various unpublished names in western Falcón. Although "Pedregal shales" (see) also form part of this transition, one formation name should suffice to include the alternating and variable lithology found in the District of Democracia in the State of Falcón.

G. D. Johnson