GUATIRE, Formación

TERTIARY (upper Miocene and/or Pliocene)

State of Miranda, Venezuela

Author of name: P. P. Wolcott, 1945 (private report).

Original reference: E. Mencher et al., 1951, correlation chart.

Original description: None published heretofore.

E. Mencher et al. (1951, correlation chart) placed the Guatire formation in the Pliocene. They showed it underlain unconformably by the upper Miocene Tuy formation and overlain unconformably by alluvial deposits of Holocene age.

W. H. Bucher (1952, p. 60) assigned the deposits of the Guatire basin to the Miocene and considered them to have been formerly continuous with those of the Santa Lucía basin and the lower Río Tuy embayment.

M. Nicklas (1953, p. 370-375) did not refer directly by name to the Guatire formation but divided its deposits into a lower or middle Tertiary Pichao conglomerate and an unnamed upper Tertiary (upper Miocene ?) unit. He thus extended the use of the name Pichao conglomerate from its type locality in the Santa Lucía basin into the Guatire basin on grounds of similar petrography and stratigraphic position. The overlying finer clastics of the unnamed unit were questionably assigned to the upper Miocene by the presence of two specimens determined by H. H. Renz to be closely related to the marine gastropod Phos (Antollophos?) springvaleensis Rutsch of the upper Miocene Springvale formation of Trinidad.

The following description of the Guatire formation is abstracted from a private report by P. P. Wolcott (1945). The formation was named after the town of Guatire in northern Miranda and is well exposed along the road to Caucagua for 6 kilometers east of Guatire as in the valley of the nearby Río Guarenas. The Guatire is composed of loosely consolidated sands and conglomerates, laminated silts and silty to pebbly clays. Its estimated maximum thickness is 400 meters (1,312 feet). The Guatire formation rests unconformably upon the Cretaceous metamorphics in the Guatire basin, upon the upper Miocene Tuy formation and the Cretaceous metamorphics in the Santa Lucía basin, and upon the upper Miocene Tuy formation, the middle Miocene Aramina and Cumaca formations, and the Cretaceous metamorphics in the lower Río Tuy embayment. The Ocumare formation was eliminated as a synonym of the Guatire. Pleistocene and Recent sediments overlie the Guatire with pronounced angularity. The few fossils recovered consist principally of fresh water gastropods and reworked Miocene foraminifera. The Guatire formation is geographically restricted to the Guatire and Santa Lucía basins and the lower Rio Tuy embayment, three separate sedimentary areas in the State of Miranda. Wolcott does not mention any basal conglomerate of the Guatire and includes the type Pichao conglomerate as the basal portion of his Tuy formation.

A. N. Dusenbury, Jr.