The Santa Cruz river basin

The Levallois method has been identified in different sectors of the basin, at different times. The variant used, called the centripetal recurrent method, is the most complex of all and seeks to obtain several flakes, planning their size and shape. This is achieved by repeatedly flintknapping the core, taking care of keeping its shape.

The earliest evidence of the utilization of this method is from the upper basin of the Santa Cruz river, dating back to 4.300 years before the present. Its use persisted until approximately 1.800 years ago. The reasons for the adoption and abandonment of this carving method are still being investigated.

Near the mouth of the Santa Cruz river into the Atlantic Ocean, evidence of the use of this method has been found between 2.800 and 1.200 years ago. In this case, the research is focused on evaluating the reasons for its utilization and if it can be due to the moment of human groups, or if they represent two independent cases.

Laminar artifacts have been recovered at different times:

• At sites located to the west, on the southern bank of the river, this type of artifacts was produced from approximately 6.200 to 4.300 years ago. It is always found in small quantities and occasionally, taking advantage of the natural shape of the nodules and employing flexible flaking techniques.

• Between 1.900 and 1.300 years before present, there is more specific evidence at sites on both sides of the basin, located both in the west and in the middle basin. Small quantities of laminar artifacts were produced, but using a much more complex knapping method. Research is underway to determine whether these changes are related to the social dynamics of hunter-gatherer groups or whether they are linked to the environment, among other factors.