Browsing by Author "Frugone-Alvarez, Matias"

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Hydroclimate variations over the last 17,000 years as estimated by leaf waxes in rodent middens from the south-central Atacama Desert, Chile
    (2023) Frugone-Alvarez, Matias; Contreras, Sergio; Meseguer-Ruiz, Oliver; Tejos, Eduardo; Delgado-Huertas, Antonio; Valero-Garces, Blas; Diaz, Francisca P.; Briceno, Matias; Bustos-Morales, Manuel; Latorre, Claudio
    Leaf cuticular waxes are one of the most important environment-plant interaction structural systems that enable desert plants to withstand extreme climatic conditions. We present a long chain n-alkyl lipids study in fresh plant leaves and rodent palaeomiddens collected along an elevational gradient in the south-central Atacama Desert of Chile, covering six different vegetation belts: Steppe (4500-4000 m asl), Puna (4000-3300 m asl), pre-Puna (3300-2400 m asl), Absolute Desert (2400-1000 m asl) and Coastal Desert (1000-0 m asl). The 28 rodent palaeomiddens analyzed from Quebrada Incahuasi (25.6 & DEG;S, 3600 m asl) span the last 17,000 years. Modern-day distribution of long-chain n-alkanes and n-alkanoic acids varies among the dominant plant associations of the Atacama Desert. These plants show a species -specific chemotaxonomy linked to the climatic conditions. Furthermore, differences in average chain length (ACL) and carbon preference index (CPI) suggest that these plant communities are highly adapted to extreme environmental conditions. The sum of leaf wax n-alkanes was highest under wet conditions, while n-alkanoic acids (between n -C24 and n -C28) increased with hyperaridity. Similarly, analysis of n- alkane time series from palaeomiddens showed that the greatest changes in leaf wax n-alkane distri-butions (ACL and CPI) corresponded to the greatest increases in moisture during the Central Andean Pluvial Event (CAPE; between 18 and 9 ka cal BP) and the Late Holocene. The shift in the palaeomidden n- alkane distributions is corroborated by the relative abundance of rainfall-dependent extra-local taxa. This is the first study to report leaf wax content obtained from ancient rodent middens, and shows promising results as a robust hydroclimate proxy for the Atacama Desert region. & COPY; 2023 Published by Elsevier Ltd.
  • Thumbnail Image
    Item
    Population dynamics and cultural niche construction during the Late Holocene in a mediterranean ecosystem (central Chile, 32°S-36°S)
    (2024) Godoy-Aguirre, Carolina; Frugone-Alvarez, Matias; Gayo, Eugenia M.; Campbell, Roberto; Lima, Mauricio; Maldonado, Antonio; Latorre, Claudio
    Understanding socio-ecological systems over the long term can shed light on past adaptive strategies in environmentally sensitive regions. Central Chile is an emblematic case study for mediterranean ecosystems, where a progressive and sustained population increase began approximately 2000 years ago alongside significant landscape changes. In this work we analyzed regional paleo-demographic trends by compiling a new database of archaeological dates over the last 3000 years, and integrating population dynamics theory with an analysis of the spatio-temporal variation of regional cultural stages. Results show three moments of marked acceleration in population growth: just before agricultural adoption, during the Archaic Period (c. 700-300 BCE); during the second half of the ECP (500-900 CE); and during the Late Intermediate Period (1200-1400 CE). We also identified periods of deceleration in per capita growth rates, although population size continued to increase (300 BCE-500 CE, 900-1200 CE and after 1400 CE). These large shifts in the per capita growth rates coincide with major cultural changes associated with social and economic aspects. The pulses of major occupation show in general terms a more intensive use of the valleys as the population size increased, although the remaining ecosystems never ceased to be occupied with different economic and symbolic emphases.
  • No Thumbnail Available
    Item
    Taguatagua 3: A new late Pleistocene settlement in a highly suitable lacustrine habitat in central Chile (34°S)
    (2024) Labarca, Rafael; Frugone-Alvarez, Matias; Vilches, Liz; Blanco, Jose Francisco; Penaloza, Angela; Godoy-Aguirre, Carolina; Lizama-Catalan, Alvaro; Oyarzo, Cristobal; Tornero, Carlos; Gonzalez-Guarda, Erwin; Delgado, Ayelen; Sepulveda, Marcela; Soto-Huenchuman, Paula
    We present the results of the excavations and analyses of the diverse and exceptional archaeological assemblage of Taguatagua 3, a new late Pleistocene site located in the ancient Tagua Tagua lake in Central Chile (34 degrees S). The anthropogenic context is constrained in a coherently dated stratigraphic deposit which adds new information about the mobility, subsistence strategies, and settlement of the early hunter-gatherers of southern South America. The age model constructed, as well as radiocarbon dates obtained directly from a combustion structure, indicate that the human occupation occurred over a brief time span around 12,440-12,550 cal yr BP. Considering taphonomic, geoarchaeological, lithic, archaeobotanical, and zooarchaeological evidence, as well as the spatial distribution combined with ethnographic data, we interpret Taguatagua 3 as a logistic and temporary camp associated mainly with gomphothere hunting and butchering. Nevertheless, several other activities were carried out here as well, such as hide and/or bone preparation, small vertebrate and plant processing and consumption, and red ochre grinding. Botanical and eggshell remains suggest that the anthropic occupation occurred during the dry season. Considering the contemporaneous sites recorded in the basin, we conclude that the ancient Tagua Tagua lake was a key location along the region's early hunter-gatherer mobility circuits. In this context, it acted as a recurrent hunting/scavenging place during the Late Pleistocene due to its abundant, diverse, and predictable resources.