CHIGUAJE Formation

TERTIARY (upper Miocene)

State of Falcón, Venezuela

Author of name: C. Wiedenmayer and M. F. Fredea, 1928 (private report).

Original reference: González de Juana, 1937, p. 202. Original description: ibid.

González de Juana (1937, p. 192) stated that the "Chiguaje marine zone" (termed "paquete merino de Chiguaje" in the Spanish edition, 1937, p. 202) crops out in the upper part of the La Vela formation. He described this unit as composed of impure sandy, and conglomeratic limestones, and prominent fossil beds and oyster banks with Ostrea virginica falconensis Hodson.

Mencher et al. (1951, correlation chart) showed the Chiguaje formation in the upper Miocene of western Falcón, conformably overlain by the Algodones formation and resting conformably on the "Taparito formation".

Information taken from private reports indicates that the type section of the formation is exposed on Cerro Chiguaje, near the town of Urumaco in north-central Falcón, beginning at the base of the lowest fossiliferous lens on the south face of the hill and extending 0.3 kilometers northeastward to the top of the uppermost fossiliferous bed on the north flank of the hill. The formation consists of dark gray and tan shales, claystones, loose yellow fine-grained, sometimes fossiliferous, sandstones and hard gray fossiliferous limestones. The thickness of the Chiguaje varies locally. At the type section it is 53 meters thick. The Chiguaje is conformable at both its lower and upper contacts with the "Taparito" and Algodones formations, respectively. The formation crops out in northwestern and north-central Falcón. A number of geologists regard the Chiguaje formation as the middle of three formations which they place in the "Codore group", while another group of geologists consider the Chiguaje to be the middle member of the Codore formation.

Leo Weingeist