ALTAMIRA, Formation

TERTIARY (upper Eocene)

State of Barinas, Venezuela

Author of name: R. L. Collins, 1937 (private report).

Original reference: F. A. Sutton, 1946, p. 1686.

Original description: none published.

The first published reference to the Altamira formation was made by F. A. Sutton (1946, p. 1686). This author states that, in order to avoid confusion in the use of the name El Mene formation, the Sinclair geological staff adopted the term Altamira formation for the El Mene formation of the Barinas area.

The Altamira formation is typically exposed in the vicinity of the town of Altamira, north of Barinas. It consists of a series of sandstones, alternating with gray shales. Sandstone sequences average 10 meters or more in thickness, medium to coarse "rained, gray, calcareous, dirty, ripple marked, weathering to brown and tan with a poor but individually abundant fauna of shallow water macrofossils, as mentioned by Sutton (ibid., p. 1686). Shales are characteristically lighter gray than the shales of the Zapa formation. At many places in the foothill section this formation is well exposed, the sandier sections forming hog-backs visible from the plane and from the ground.

The Altamira formation overlies the dark shales of the Masparrito formation (unpublished), the contact is not very sharp, there seems to be a gradation between the formations. The upper contact with the red beds of the Parángula formation is marked by an unconformity.

Paleontological reports have determined the age of this formation as upper Eocene.

Ivan A. Koves