PEÑA MOTA, Conglomerate

TERTIARY (Oligocene)

State of Guárico, Venezuela

Author of name: P. Leuzinger, 1944 (private report).

Original reference: H. D. Hedberg, 1950, p. 1203.

Original description: ibid.

P. Leuzinger (1944, private report) gave the name Peña Mota conglomerate to a thick series of conglomerates interbedded with mottled claystones exposed immediately north of Altagracia de Orituco, at the Peña Mota ridge, from which its name is derived; this series extends eastward, along the south flank of the mountain front, in the State of Guárico.

H. D. Hedberg (1950, p. 1203), was the first to describe in publication the Peña Mota conglomerate which he includes in the Santa Inés group. It consists of varicolored, coarse, pebble to boulder conglomerates, interbedded with sandy mottled claystones. Pebbles, cobbles and boulders are largely sandstone; quartz and chert.

The stratigraphic relations of the Peña Mota conglomerate are not yet fully established. Hedberg considers the unit to be at the top of the Caño Dulce formation and below the Bruzual claystone, but this interpretation is disputed by some geologists.

The Peña Mota conglomerate appears to represent fluvial or deltaic deposits, predominantly of Oligocene age.

José Luis Padrón