FIRST COAL HORIZON

TERTIARY (upper Eocene-Oligocene?)

State of Zulia, Venezuela

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

Original reference: R. A. Liddle, 1928, p. 288.

Original description: ibid.

The First Coal horizon is, according to Liddle (1928, p. 288), the youngest of three Tertiary lignite and coal-bearing horizons. Although the term does not conform to the requirements of nomenclature it is retained because of its general use until a geographic type locality can be selected.

The First Coal horizon consists of grayish-brown, usually crossbedded, micaceous sandstones, gray, micaceous clay-shale intercalated with soft, brown lignitic coal and lignite. The entire formation is indicative of lagoonal or estuarine conditions. The lignites of Cienfuegos belong to the First Coal horizon according to Liddle (1928, p. 290).

According to Sutton (1946, p. 1672 and 1673), the First Coal horizon correlates with the upper coal measures of the Carbonera formation and the Carbonera formation of Notestein et al. (1944, p. 1196-1201), comprises the First Coal horizon and the Sandy Shale horizon of Liddle. The First Coal and the Sandy Shale of the type section on the Tarra anticline, district of Colón, state of Zulia, seem, according to Sutton, to be limited to the Eocene, whereas the Carbonera apparently includes strata of upper Eocene and middle Oligocene age.

W. A. Mohler