LORA, Coal Measures

See THIRD, Coal Formation

THIRD, Coal Formation

UPPER CRETACEOUS-TERTIARY (lower Eocene)

State of Zulia, Venezuela

Author of name: R. A. Liddle, 1928.

Original reference: R. A. Liddle, 1928, p. 181.

Original description: ibid.

The Third Coal "horizon", a name used in the Colón district, State of Zulia, was first published by Liddle (1928, p. 181) and referred to as Third Coal formation by Staff of Caribbean Petroleum Company (1948, p. 614). It consists of grey sandy shales, lenticular sandstones, carbonaceous shales with coal seams, and mottled shales. For subsurface correlations it is subdivided into four members, the most important one being the Tabla sands, an outstanding group of lenticular sandstones in the lower third of the formation. The total thickness, according to the Staff of Caribbean Petroleum Co., is about 1.500 feet. Characteristics of the formation are irregular sedimentation and brackish-facies. According to the Staff of Caribbean Petroleum Co. (1948, p. 614) a good part of the Third Coal formation belongs to the Eocene and Paleocene, but it is not certain that the lithologic change between the Mito Juan and the Third Coal coincides exactly with the Cretaceous-Tertiary boundary. The Third Coal formation rests conformably on the Mito Juan formation and is overlain by the Mirador formation which contact is transitional.

According to Sutton (1946, p. 1656) the Third Coal "horizon" can be correlated with the Catatumbo, Barco and Los Cuervos formations (Orocué group) as described in the Barco concession by Notestein et al. (1944, p. 1186-1194). Notestein et al. (1944, p. 1189) make some restrictions saying that the Catatumbo correlates directly with the lower part of the Third Coal "horizon" of Western Venezuela and with some of the uppermost Mito Juan beds as the top of that formation is, at least locally, drawn in Western Venezuela. According to the Staff of Caribbean Petroleum Co. (1948, p. 614), the Third Coal formation can be correlated closely with the Barco and Los Cuervos formations which statement is not quite correct, as it also correlates with practically the entire Catatumbo. According to Sutton (1946, p. 1663), the Eocene portion of the Third Coal "horizon" of the Colón district, Zulia, and the combined Barco and Los Cuervos formations of the Barco concession in Colombia correlate with the Angostura and the Marcelina formations as well as with the Trujillo formation.

González de Juana (1951, p. 266-267) considers the Angostura formation to be equivalent to the Third Coal "horizon" and he believes that the age is possibly Paleocene in its lower part and comprises the entire lower Eocene and part of the middle Eocene.

According to Sutton (1946, p. 1665), the name Lora Coal measures of Garner (1926, p. 680) outcropping in the upper part of the Lora river in the southern Perijá district is another unsuitable term for Third Coal "horizon".

W. A. Mohler