SOLITO, Formation

TERTIARY (Upper Oligocene ?)

State of Falcón, Venezuela

Author of name: Geologists of the S.O.V. (present Creole Petroleum Corp.)

Original reference: C. González de Juana, 1937, p. 208-209.

Original description: ibid.

C. González de Juana (1937, p. 208-209) published the name "Solito formation", which, he said, had been widely used in private reports by Wiedenmayer, Richardson, Leuzinger, Kugler and Vogel. The type location was not given, nor was a type section designated, but the author stated that important outcrops are exposed south of the Ricoa river, outside of the area discussed in his paper, as well as to the southeast of Cumarebo in the Moturito hill, east of the thrust fault of the Ricoa river. The formation is described as a sequence of fine to medium-grained sandstones, friable, generally hardened by weathering, speckled black and white. The distinction between the Solito formation and similar sandstones in underlying horizons, stated González de Juana, is almost impossible. The fossils consist of arenaceous foraminifera difficult to identify, some molds of Turritella and specimens of Pecten and Cardium which suggest an upper Oligocene age. No thickness was given. In the stratigraphic table which accompanied the report, the Solito formation was shown below the Cerro Pelado formation (referred to the lower Miocene).

Presumably, the "Solito-Curamichate sands" which figure in the correlation table by Senn (1940, p. 1579) are not the same as González de Juana's Solito formation, since they are shown as correlative with the top of the Cerro Pelado formation. (See CURAMICHATE, Sandstone).

Payne (1951, p. 1854) states that "the group of sandstones which make up the 'Solito formation' of González was found not to deserve formational rank". He reduces the Solito to the status of a member of his Ricoa formation, to which he assigns upper Oligocene age. The member, he states, together with two other sandy members (Turuguapo and Lomas), shales out or lenses out to the north, northeast and east of the type locality. A sand possibly equivalent to the Solito was found in the well Ricoa N° 1. (Payne, 1951, p. 1857). Other geologists at present recognize the Solito as a formation. (See RICOA, Formation).

Frances de Rivero

CURAMICHATE, Sands

TERTIARY (upper Oligocene)

State of Falcón, Venezuela

Author of name: C. Wiedenmayer, 1924.

Origina; reference: C. Wiedenmayer, 1924, p. S10.

Original description: ibid.

C. Wiedenmayer (1924, p. 501-511) created the name Sandstein-Sandmergelserie (Curamichateserie) for a deltaic formation consisting of sandy marls, cross-bedded sandstones and calcareous sandstones, outcropping in the coastal cliff near the village of Curamichate, northwest of San Juan de los Cayos, Eastern Falcón. He assigns an Oligocene age to this unit. Unfortunately, Wiedenmayer, due to erroneous correlation, also includes here the lithologically different orbitoidal limestones and marls of Cerro Campana (Guayavalserie) which are of predominantly upper Eocene age and should be excluded from his Curamichateserie. A. Senn (1935, p. 77, Taf. VIII) named this unit the Curamichate-Sande, which he places on top of his A3-4 Agua Salada zone, underlying his A3 zone; an upper Oligocene age is assigned to this unit. Later the same author (1940, p. 1580, Stratigraphic Correlation Chart) refers to this unit as the Solito-Curamichate sands. It is recommended to use henceforth the name Curamichate sands for this unit.

Liddle (1946, p. 449, 461) includes the Curamichate sands into the uppermost part of the Cerro Pelado formation, and reports some coal heds from this unit (p. 433).

In the nomenclature of H. H. Renz (1948, p. 8, 53) the Curamichate sands fall within the lower part of the Agua Salada group, near the boundary between the San Lorenzo and Pozón formations, and represent a local sandy facies development. The Curamichate sands lie within the Siphogenerina transverse zone, to which an upper Oligocene age is assigned.

H. H. Renz

RICOA, Formation

TERTIARY (upper Oligocene)

State of Falcón, Venezuela

Author of name: H. G. Kugler, 1946 (private report).

Original reference: A. L. Payne, 1951, p. 1854.

Original description: ibid., p. 1856, 1857.

Payne (1951, p. 1856, 1857) stated that the Ricoa formation of upper Oligocene age is the oldest formation exposed in the Cumarebo area. It is essentially argillaceous. He pointed out that a thickness of 8,000 feet has been computed for the thickness of the Ricoa in the type area. Payne mentioned that the thickness is made up of 2,000 feet of Acurigüita shale and of a rest of 6,000 of the formation. However, the thickness may be greater than 8 000 feet, inasmuch as the Acurigüita shale was approximately 3,900 feet thick in the well Las Pailas N° 1, the only well in which this shale was completely penetrated. The three sand members, the Turaguapo, Solito and Lomas sands, though well developed at and near the type surface localities, shale out or lense out on the north, northeast, and east, as indicated by surface geology and by subsurface data.

Most geologists now consider the Ricoa formation to be equivalent to the combined Agua Clara, Solito and Querales formations They regard the Turaguapo sand and the Acurigüita shale as middle and lower members, respectively, of the Agua Clara formation in the Cumarebo area. The Solito sand is given formation rank and the Las Lomas sand is carried as the upper member of the Querales formation in the Cumarebo area.

Leo Weingeist