Sitio arqueológico QS1 (provincia de Buenos Aires, Argentina): evidencias palinológicas de fluctuaciones paleoclimaticas durante los últimos 1000 años a.p.

Abstract

A palynological analysis was effected in the Archaeological Site QS1 , lower basin of the Quequén Salado river (Buenos Aires province), which aimed at the reconstruction of the landscape in which aborigines of the region may have lived during the last 1000 years. With the identified pollinic spectrums it was possible to determine four Pollen Zones, which evidenced the climatic fluctuations of the area. In QS1 -4 Pollen Zone (more than 960 ± 40 years B. P.), only pollen grains were identified; “non-pollinic” microfossils indicated variable humidity conditions. QS1 -3 Pollen Zone (940±40 / 790±40 years B.P.) reflected a slight improvement in the climate, which is associated to the growth of grasslands and the presence of the highest proportion of Poaceae of the profile. The most relevant register of lithic artifacts, pottery and guanaco bones was found at the top of the QS1 -4 Pollen Zone and partly in the QS1 -3 Pollen Zone. From 360 ± 40 years B.P. to present time, QS1 -2 and QS1 -1 Pollen Zones reflected climate deterioration and anthropic indicators in the plant communities.