LISURE, Formation

CRETACEOUS (middle-upper Albian)

State of Zulia, Venezuela

Author of name: E. Rod, 1953 (private report).

Original reference: E. Rod and W. Maync, 1954, p. 209.

Original description: ibid.

The name Lisure formation, first used by E. Rod in 1953, was introduced in the literature in 1954 (Rod and Maync, 1954, p. 202, 209).

The Lisure formation includes the Aguardiente formation and the lower part of the Capacho formation as used by F. A. Sutton in the Sierra de Perijá, Zulia (Sutton, 1946, p. 1645-1647). It consists of blue-gray or greenish, glauconitic, medium to fine-grained sandstones; glauconitic, often hematitic sandy limestones; laminated micaceous sandstones with sandy, pyrite-bearing shale breaks; and lenticular limestones and rare beds of coquinoid limestone. Its thickness ranges from 50 to 180 meters.

The formation is named after Caño Lisure, a tributary of Caño Maraca, Sierra de Perijá, Zulia. The reference section is on Caño Cusare, a tributary of Río Chaparro, Sierra de Perijá.

The Lisure Formation is known from outcrops and well sections (eastern Colombia, Sierra de Perijá, Amana-Guasare area, Maracaibo Platform, Toas Island). It seems to rest disconformably on the Apón formation conformably (transitional) with the overlying Maraca formation.

Because of its characteristic lithologic features, the rock unit designated as Lisure formation is an outstanding stratigraphic key bed. Microfauna: Discorbis minima Vieaux, Haplostiche texana (Conrad), Lituola subgoodlandensis (Vanderpool), Textularia rioensis Carsey, etc. Echinoids of probably middle Albian age were found in the Lisure formation on Río Cogollo, Sierra de Perijá (Sutton, 1946, p. 1644; Rod and Maync, 1954, p. 200-201).

The Lisure formation is considered to be of middle Albian age; the top part may represent upper Albian.

Wolf Maync