Climate deteriorations and Neanderthal demise in interior Iberia

Abstract

Time and circumstances for the disappearance of Neanderthals and its relationship with the advent of Modern Humans are not yet sufficiently resolved, especially in case of the Iberian Peninsula. Reconstructing palaeoenvironmental conditions during the last glacial period is crucial to clarifying whether climate deteriorations or competition and contacts with Modern Humans played the pivotal role in driving Neanderthals to extinction. A high-resolution loess record from the Upper Tagus Basin in central Spain demonstrates that the Neanderthal abandonment of inner Iberian territories 42 kyr ago coincided with the evolvement of hostile environmental conditions, while archaeological evidence testifies that this desertion took place regardless of modern humans’ activities. According to stratigraphic findings and stable isotope analyses, this period corresponded to the driest environmental conditions of the last glacial apart from an even drier period linked to Heinrich Stadial 3. Our results show that during Marine Isotope Stages (MIS) 4 and 2 climate deteriorations in interior Iberia temporally coincided with northern hemisphere cold periods (Heinrich stadials). Solely during the middle MIS 3, in a period surrounding 42 kyr ago, this relation seems not straightforward, which may demonstrate the complexity of terrestrial climate conditions during glacial periods.

Origins and genesis of loess deposits in central Spain, as indicated by heavy mineral compositions and grain‐size variability

“…) according to the lithological units described by Wolf et al . (). Furthermore, in order to assess the heavy mineralogical signature of the potential source areas, seven reference samples were taken from the main geological units in the surrounding area that are: (i) Tertiary marls; (ii) metamorphic units and granites from Palaeozoic rocks; and (iii) Mesozoic sedimentary rocks (Fig.…”

“…In higher slope positions, SU‐3 consists of reworked marl material that rests on bedrock (SU‐1, gypsum marl). Optically‐stimulated luminescence (OSL) dating of SU‐3 suggests sedimentation ages beyond 100 ka (Wolf et al ., ). According to a first interpretation, sediments of SU‐3 consist of soil material that was eroded, transported and deposited by a mixture of fluvial and slope processes.…”

“…Recently, loess in the upper Tagus Basin has been demonstrated to be a valuable environmental record for the late Pleistocene (Wolf et al ., ). Given that sedimentary archives in interior Iberia are very rare for that period, it is important to explore and understand this loess record in detail.…”

“…These sections stretch over a distance of more than 30 km along the Tagus River valley and have been described in detail in Wolf et al . (). Since the sedimentation dynamics of these sections have been worked out with a high temporal resolution, it was possible to evaluate loess sources for distinct sedimentation periods over the last glacial.…”

The MIS 13 interglacial at Ceprano, Italy, in the context of Middle Pleistocene vegetation changes in southern Europe

“…A substantial body of marine and terrestrial pollen evidence shows that millennial/centennial-scale instability has been a pervasive feature of the mode of change across southern Europe during glacial periods, with arboreal population size and composition changes associated with sea-surface temperature variations (Sánchez Goñi et al, 2000, 2016aRoucoux et al, 2001Roucoux et al, , 2006Roucoux et al, , 2008Roucoux et al, , 2011Margari et al, 2010Margari et al, , 2014Fletcher et al, 2013). It has been recently suggested that the abandonment of inner Iberian territories by the Neanderthals around 42 ka was caused by deteriorating environmental conditions (Wolf et al, 2018). It is reasonable to assume that similar climatic oscillations occurring during the Middle Pleistocene, would have had a significant impact on hominin populations.…”