AGUARDIENTE, Formation

CRETACEOUS

Author of name: F. B. Notestein et al., 1944.

Original reference: F. B. Notestein et al., 1944, P. 1177.

Original description: ibid.

In the Barco Concession, Santander, Colombia, the Lower Cretaceous Uribante formation was subdivided into three members, viz. from top to bottom, the Aguardiente, Mercedes, and Tibú members (Notestein et al., 1944 p. 1174). The name Aguardiente is derived from the conspicuous topographie dip slope of the Filo del Aguardiente, south of the Barco Concession, Colombia.. The Aguardiente member consists of "extremely hard and calcareous gray or light-green fine to coarse-grained cross-bedded glauconitic sandstones"... "Interbedded with the more glauconitic sandstones are gray, only slightly glauconitic sandstones with micaceous-carbonaceous partings. Some thin laminae and beds of black micaceous -carbonaceous shale are present, and a few thin beds of limestone occur in the lower part. Locally, the sandstones are so calcareous as to approximate arenaceous limestones" (Notestein et al., 1944, p. 1177).

In the Barco Concession, and west of same, the thickness of the Aguardiente member amounts to 148-160 meters (ibid.).

The Aguardiente member, distinguished in the Barco Concession as the uppermost member of the Uribante formation, was given formation rank by F. A. Sutton (1946, p. 1645). Realizing that the base of the Aguardiente formation corresponds to the boundary of a new depositional cycle, Sutton regarded the Aguardiente as the basal part of his upper Cogollo group.

The lithologic characteristics of the Aguardiente as reported from the Barco Concession also hold true in the Maracaibo Basin, Zulia, except for the varying glauconite content.

In the Mérida Andes (Táchira), a maximum thickness of 530 meters for the Aguardiente formation has been measured. In the Tarra Field, southern Zulia, an approximately 350 meters thick complex of hard micaceous -sandstones with conglomeratic parts and shale streaks is distinguished as Aguardiente member (top of the Uribante ("Tomón") formation) which grades into the Capacho formation ("Cogollo" in obsolete usage; see Cogollo formation) (Staff of Caribbean Petroleum Company, 1948, p. 613; Mencher et al., 1953, p. 730). The formation thins to 50-330 meters (Trujillo), and a thickness of a mere 15-20 meters is recorded in the Sierra de Perijá, Zulia (Sutton, 1946, p. 1646). More recent field work proved, however, that the total thickness of the glauconitic sandy rock unit in the Sierra de Perijá actually amounts to 50-180 meters (E. Rod, 1949-1950). The term Aguardiente formation was, accordingly, used in a restricted sense by F. A. Sutton, and part of the glauconite-bearing beds was included in Sutton's Capacho Formation. On this account, the new name was included in Sutton's Capacho formation. On this account, the new name Lisure formation was introduced by E. Rod (1953) for the total thickness the Apón and the Capacho-Maraca formations (Rod and Mayne, 1954, p. 209 etc.) (see Lisure formation).

The sudden change in the type of deposition from the limestones of the Apon formation to the greensand facies of the Lisure formation suggests a disconformable contact; the boundary with the overlying Capacho-Maraca formation is conformable. In Trujillo, however, the contact AguardienteCapacho appears to mark an unconformity (breccia level, conglomeratic beds).

The Aguardiente formation is consistently developed over a large area (eastern Colombia, Mérida Andes, Maracaibo Basin). The Carora sandstone of W. Sievers (1896), described as a very hard white quartz sandstone, rests on reddish-gray shales and underlies the fossiliferous Middle Cretaceous limestones of Carora and Barbacoas (Capacho formation) (Sievers, 1896, p. 95-96). According to W. Sievers, the Carora sandstone corresponds to the "Neocomian Uribante sandstone" of the Andes (Sievers, 1896, p. 249); it correlates with the Aguardiente formation of present-day usage. In part, however, it is of Eocene age (Kehrer, 1937, P. 60). The name Carora sandstone was also applied by W. Sievers (1896, p. 227) to sandstones cropping out in the mountains of Piritu, Eastern Venezuela. The name Carora sandstone is discarded.

Age of the Aguardiente formation: A ?Cenomanian age is assumed by some authors. The occurrence of Orbitolina concava-texana (Roem.) in the Aguardiente Formation in Lara, however, is suggestive of an Albian age, since the mentioned species of Orbitolina was hitherto not found above the middle Albian (Guácharo limestone of the Chimana formation of Eastern Venezuela) Rod and Maync, 1954, p. 269).In Barbacoas (Lara) and Chejendé (Trujillo) the Aguardiente formation is overlain by the Capacho formation which carries middle and upper Albian (-Vraconian) ammonite genera (see Capacho formation); the basal portion of the Capacho formation has also yielded specimens of Mariella bergeri (Brongn.) which suggests an upper Albian-lower Cenomanian age. Accordingly, a middle to upper Albian age is assigned to the Aguardiente formation (Rod and Mayne, 1954, p. 208-209).

Wolf Maync