GUAYABO, Group

See GUAYABO, Formation

GUAYABO, Formation

TERTIARY (Miocene)

State of Zulia, Venezuela

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

Original reference: R. A. Liddle, 1928, p. 333.

Original description: ibid.

The Guayabo was originally described as a formation by Liddle (1928, p. 333), but Notestein et al. (1944, p. 1203) have raised it to a group status without, however, dividing it into its component formations. Also Sutton (1946, p. 1708) calls the Guayabo a group as well as González de Juana (1952, p. 316).

The Guayabo takes its name from Cerro Guayabo in the southern part of the Colón district, in southwestern Zulia.

Liddle (1928, p. 333) gives the following lithological description of the Guayabo formation: in the upper part there is a series of mottled red and white clays and sands with which some vari-colored clays and greyishbuff sands are intercalated. Beneath these variegated beds there is a thicker series of grey, micaceous, arenaceous, locally lignitic shales, soft, crossbedded, yellow, grey and buff sandstones and sands, and highly ferruginous conglomerate. The lower and more shaly part of the Guayabo varies laterally both in character and thickness.

According to Sutton (1946, p. 1708) Liddle has apparently included some of his Upper Shale "horizon" in the base of his Guayabo formation. Eliminating this, there is left about 305 meters for the Guayabo of mottled red and white clays and sandstones, with which some varicolored clays, greyish buff sandstones, and ferruginous conglomerates are intercalated, and a series of overlying conglomeratic sandstones and conglomerates, interbedded with light grey clays.

The Guayabo is known in the states of Zulia and Táchira, in the Onia region of western Mérida and in the Barco concession, Colombia. The age of the Guayabo formation, according to Sutton, is middle and upper Miocene.

According to González de Juana (1952, p. 316), the Guayabo is nonmarine and contains locally some macrofossils as Unio sp., which indicates fresh water. The Guayabo is underlain by the Upper Shale formation (León formation). The same author mentions a thickness of 500 m. in Táchira and in the Los Manueles field in Colón. In the Barco concession according to Notestein et al. (1944, p. 1204) the thickest section is 803 m., but the top of the formation is not known. Approximately 5 kilometers southeast of Cúcuta a section of 2,640 meters of Guayabo was measured; however, according to Notestein ef al. (1944, p. 1204) probably the La Villa is represented in the upper part of this section. Hedberg (personal communication acc. to Notestein et al., p. 1204) believes that the Guayabo is equivalent to part of the El Fausto, Los Ranchos and La Villa formations in western Venezuela.

According to Sutton (1946, p. 1709) the Guayabo of Táchira (Kehrer, 1938, p. 45) has been split by Abadilla (private report), who places the lower mottled formation in the Isnotú and assigns the upper conglomeratic formation to the restricted Betijoque. The Guayabo of the Onia region of western Mérida has received the same treatment.

The name Guayabo has been misspelled "Gayabo" in Mencher et al. (1951), figs. 17, 20; p. 41, 43 of the English edition; p. 43,45 of the Spanish edition.

W. A. Mohler