PERIQUITO, Formation

TERTIARY (predominantly lower Oligocene)

State of Anzoátegui, Venezuela

Author of name: H. D. Hedberg, 1939 (private report).

Original reference: H. J. Funkhouser, et al., 1948, p. 1870-1872.

Original description: ibid.

The Periquito formation was named by Hedberg in 1939 (private report) after the Periquito property, in the vicinity of the Santa Ana village, to designate in the first Santa Ana wells, a predominantly sandy stratigraphic unit underlying the Oficina formation. With additional information, the equivalence of the Periquito formation to the Merecure formation of the mountain front area (Hedberg and Pyre, 1944, p. 15-21) became sufficiently probable so that the unit in those wells was known as the Periquito member of the Merecure formation (Funkhouser et al., 1948, p. 1870-1872). Later, Hedberg (1950, p. 1196-1199) raised the Merecure formation to group rank and consequently, the Periquito member to formation.

In the wells of the Anaco fields, the formation is characterized principally by the abundance of light-gray to dark-gray, massive to poorly bedded, hard, fine to coarse-grained sandstones and grits, broken by laminae and thin beds of hard black carbonaceous shale and gray claystone and siltstone; cross-bedding is common and secondary growth of quartz grains is characteristic (Funkhouser, et al., 1948, p. 1871).

According to Mencher et al. (1951, p. 59-60) the Periquito formation has been penetrated in all the fields of the Anaco area but has been completely drilled through only in one well of the Toco field. Here, the formation is about 1,800 feet thick but thickens northeastward. The contaet with tne overlying Oficina formation appears to be conformable, but there is marked unconformity with the underlying Cretaceous Temblador formation.

Hedberg (1950, p. 1198, 1205) correlates the Periquito formation with the Naricual formation and states that the uppermost part of the Periquito formation grades laterally into the basal Oficina "U sands" of the Greater Oficina fields.

Because the formation is practically barren of fossils, its age has not been determined with certainty; however, the stratigraphic position and correlation with the Merecure group in the mountain front area suggest that it is predominantly lower Oligocene.

Gustavo Feo-Codecido