[3][4][5] Based on biostratigraphy, the Río Seco de la Quebrada Formation is considered to have formed during the Anisian stage, as it shares fauna with the upper subzones of the Cynognathus Assemblage Zone in South Africa.

However, radiometric dating controversially argues that it was deposited during the early Carnian stage, 10 million years younger than expected otherwise.

The Puesto Viejo Group is a geologically isolated succession of Triassic sedimentary and igneous rock exposed in the area of the San Rafael Block.

[6] The lower portion of the Río Seco de la Quebrada Formation is dominated by poorly-sorted and trough cross-bedded conglomerate and bedded coarse sandstone.

The lower and upper portions of the formation are separated by a thick andesite layer formed by lava flows from one or more fissure eruptions.

[8] More recently, SHRIMP Uranium-Lead dating obtained an age of 233.8-237.8 Ma from an ignimbrite layer directly underlying the RSQ.