The northern margin of the Santa Cruz river basin

The earliest evidence of human occupation of this margin dates back to about 8.500 years ago and was found at  Yaten Guajen 12 site, in the homonymous canyon, which flows into the left bank of the Santa Cruz river (figures). In this canyon the basalts reach the water table, so water is available. An artifact was recovered at this site whose raw material presents macroscopic similarities with those found in the south of the Deseado Massif, so it could have been transported from there.

Human Occupations in the area are very discontinuous, with periods in which no sites have been recorded so far, although further research is necessary.

The majority of the occupations are dated between 3.100 years ago and the arrival of the Europeans and were found in different canyons. The lack of dates for the intermediate period can probably be related to the existence of periods of aridity in this entire sector, as Brook's research has showed.

Engraved rock motifs are common in these canyons, which extend - although not continuously - for more than 20 km (figures). As Gradin has already indicated, they are similar to those found on the plateaus located to the northwest and to the engravings present in La Flecha, north of the Chico river basin, which has led him to suggest the existence of circulation between these spaces. There are also similarities with the north of the Deseado Massif, which must continue to be explored. The investigations on rock motifs and techniques carried out by D. Fiore, A. Acevedo and M. Ocampo within the framework of the project allowed us to add new motifs to those shared between these spaces and propose, on the other hand, the existence of some variations between the canyons from the north margin of the Santa Cruz river. The analyses of Geographic Information Systems (GIS) have allowed us to consider which are the best circulation routes between these spaces (see Spatial Analysis - GIS in Research Lines).

On the other hand, the most recent work has allowed us to identify a small rock shelter with superimpositions of painted motifs (figure) that present, broadly speaking, similarities with techniques and motifs present both further north, in the south of the Deseado Massif, and to the south of the Santa Cruz river basin, which are being analysed with the advice of N. Carden.

Recent analyses carried out with B. Gilio and L. Vetrisano using Geographic Information Systems suggest the use of obsidian from 17 de Marzo - located south of the Deseado Massif, see "Chico river basin" section - in the case of the easternmost canyons, such as Yaten Guajen. The discovery of an obsidian artifact with cortex similar to that of this source in an excavation carried out in the course of this canyon also supports this idea.