Date Published: April 24, 2019
Publisher: Public Library of Science
Author(s): Lucia Leierer, Margarita Jambrina-Enríquez, Antonio V. Herrera-Herrera, Rory Connolly, Cristo M. Hernández, Bertila Galván, Carolina Mallol, Michael D. Petraglia.
Middle Paleolithic lithic and faunal assemblages throughout Eurasia reflect short-term Neanderthal occupations, which suggest high group mobility. However, the timing of these short-term occupations, a key factor to assess group mobility and territorial range, remains unresolved. Anthropogenic combustion structures are prominent in the Middle Paleolithic record and conceal information on the timing and intensity and natural setting of their associated human occupations. This paper examines a concentration of eleven combustion structures from unit Xb of El Salt, a Middle Paleolithic site in Spain through a geoarchaeological approach, in search of temporal, human impact and paleoenvironmental indicators to assess the timing, intensity and natural setting of the associated human occupations. The study was conducted using micromorphology, lipid biomarker analysis and compound specific isotope analysis. Results show in situ hearths built on different diachronic topsoils rich in herbivore excrements and angiosperm plant residues with rare anthropogenic remains. These data are suggestive of low impact, short-term human occupations separated by relatively long periods of time, with possible indicators of seasonality. Results also show an absence of conifer biomarkers in the mentioned topsoils and presence of conifer charcoal among the fuel residues (ash), indicating that fire wood was brought to the site from elsewhere. A microscopic and molecular approach in the study of combustion structures allows us to narrow down the timescale of archaeological analysis and contributes valuable information towards an understanding of Neanderthal group mobility and settlement patterns.
What is the approximate amount of time that Neanderthal groups occupied any given place in the landscape? How much time passed before they returned to that same place? These questions are key to understand Neanderthal group mobility and settlement patterns.
Our study of El Salt unit Xb adds to the few Middle Paleolithic sites in Europe that have yielded well-preserved combustion structures as confirmed through microstratigraphic analyses: Abric Romaní [57,74,75], Gorham’s Cave , Grotte XIV [168,169], Klissoura Cave , Lakonis Cave , Pech de l’Azé IV [172,173], Roc de Marsal , Vanguard Cave , and El Salt unit Xa . The BLs of combustion features from El Salt unit Xb were formed through anthropogenic burning of an underlying organic-rich natural surface in an environment vegetated by angiosperms, including Celtis trees and intermittently occupied by herbivores and Neanderthals. These fires were fueled by wood gathered away from the site. The paucity of Neanderthal occupation during the formation of El Salt unit Xb, possibly representing at least four successive low impact human occupation events, with enough time in between to allow for the formation of an organic rich soil and occupations most likely in winter, spring and/or summer.