MARACAIBO, Beds

See MARACAIBO, Formation.

MARACAIBO, Formation

TERTIARY (Pliocene) - QUATERNARY (Pleistocene)

State of Zulia, Venezuela

Author of name: unknown.

Original reference: A. H. Garner, 1926, p. 683.

Original description: ibid.

The Maracaibo formation of Garner (1926, p. 683) consists, in the vicinity of Maracaibo, State of Zulia, of massive, cross-bedded, poorly sorted sands and mottled clays, with much iron oxide. The age is indicated by the same author as Pliocene. According to Liddle (1946, p. 377) the "Maracaibo beds" comprise the beds overlying the Eocene in the Maracaibo basin and Sutton (1946, p. 1712) considers the Maracaibo formation of Garner as an obsolete synonym for the El Milagro formation near Maracaibo.

Tash (1937, p. 161) introduced the name Maracaibo group which is subdivided in Upper Maracaibo, Middle Maracaibo and Lower Maracaibo. The age is indicated as Upper Tertiary.

The Upper Maracaibo (or Santa Bárbara conglomerate) is a coarse, poorly cemented conglomerate, whose only components are the sandstones of the Misoa-Trujillo formation.

The Lower Maracaibo is characterised by mottled clays, which are gray to bluish-gray (sometimes rather sandy) mottled with yellow, orange, and deep red colours. Tash points out the difficulty of distinguishing between the subdivisions of the Maracaibo group, especially in the vicinity of Mene Grande.

The thickness is estimated in the Trujillo foothills between 200 meters and 960 meters, and in the Mene Grande area about 930 meters have been measured. In the wells of the Mene Grande field the maximum thickness penetrated is about 1000 metera.

The Maracaibo group of Tash overlies unconformably the Eocene and is overlain unconformably by the Quaternary.

W. A. Mohler