U-Th dating of carbonate crusts
reveals Neandertal origin of Iberian
D. L. Hoffmann,1 C. D. Standish,2 M. García-Diez,3 P. B. Pettitt,4 J. A. Milton,5
J. Zilhão,6,7,8 J. J. Alcolea-González,9 P. Cantalejo-Duarte,10 H. Collado,11 R. de Balbín,9
M. Lorblanchet,12 J. Ramos-Muñoz,13 G.-Ch. Weniger,14,15 A. W. G. Pike2†
The extent and nature of symbolic behavior among Neandertals are obscure. Although
evidence for Neandertal body ornamentation has been proposed, all cave painting has been
attributed to modern humans. Here we present dating results for three sites in Spain that
show that cave art emerged in Iberia substantially earlier than previously thought.
Uranium-thorium (U-Th) dates on carbonate crusts overlying paintings provide minimum
ages for a red linear motif in La Pasiega (Cantabria), a hand stencil in Maltravieso
(Extremadura), and red-painted speleothems in Ardales (Andalucía). Collectively, these
results show that cave art in Iberia is older than 64.8 thousand years (ka). This cave
art is the earliest dated so far and predates, by at least 20 ka, the arrival of modern humans
in Europe, which implies Neandertal authorship.
The origin of human symbolism is a central concern of modern paleoanthropology (1). For the European Middle Paleolithic and the African Middle Stone Age, symbolic be- havior has been inferred from the use, presumably for body adornment, of mineral pigments,
shell beads, eagle talons, and feathers (2–7). Cave
and rock art constitutes particularly impressive
and important evidence for symbolic behavior
(8), but little is known about the chronology of its
emergence, owing to difficulties in precise and
accurate dating (9).
Claims for Neandertal authorship of cave art
have been made (10, 11). However, ambiguities of
indirect dating and uncertainty in distinguishing
between natural and intentional modification
(12, 13) leave these claims unresolved. Recent
technical developments enable the possibility of
obtaining age constraints for cave art by U-Th
dating of associated carbonate precipitates (14).
This dating approach can provide robust age
constraints while keeping the art intact. However, it is a destructive technique, in that a carbonate sample is required (albeit, a very small sample,
typically <10 mg) and is taken not
from the art itself but from the associated carbonates. The key condition
is demonstrating an unambiguous
stratigraphic relationship between
the sample and the art whose age
we wish to constrain. Dating of carbonate crusts formed on top of the
art provides a minimum age (15).
For art painted on top of carbonates (e.g., on flowstone walls, stalagmites, or stalactites), dating the
underlying “canvas” provides a maximum age (15).
With this approach, the earliest
results so far are for a hand stencil
from Leang Timpuseng, Sulawesi
(Indonesia), with a minimum age
of 39.9 thousand years (ka) (16),
and a red disc on the Panel of Hands
in El Castillo, Cantabria (Spain),
with a minimum age of 40.8 ka (17).
Whereas the art in Sulawesi has
been attributed to modern humans,
the minimum age for the red disc in
El Castillo relates to a point in time
when it could be attributed to either
Cantabria’s first modern humans or
the region’s earlier Neandertal populations (18, 19).
Here we report U-Th dating re-
sults of carbonate formations as-
sociated with rock art in three
Spanish caves: La Pasiega (Cantabria), Maltravieso
(Extremadura), and Doña Trinidad (or Ardales;
Andalucía) (fig. S1) (20). Our criteria for sample
selection and subsequent sampling strategy strict-
ly followed previously described methods (14).
The reliability of the U-Th dating results is con-
trolled by quality criteria for the carbonate (14)
as well as by the collection and analysis of mul-
tiple subsamples of a given crust.
La Pasiega is part of the Monte Castillo cave
art complex, a World Heritage Site that also includes the caves of El Castillo, Las Chimeneas,
and Las Monedas. Together, these caves show
continued human occupation throughout the past
100 ka. At La Pasiega, the rock art comprises
mainly red and black paintings, including groups
of animals, linear signs, claviform signs, dots, and
possible anthropomorphs (21). Maltravieso was
episodically used by hominin groups during the
past 180 ka (22); it contains an important set of
red hand stencils (~60), which form part of a
larger body of art that includes both geometric
designs (e.g., dots and triangles) and painted and
engraved figures (23). Ongoing excavations have
shown that Ardales was occupied in the Middle
and Upper Paleolithic. Its walls feature an impressive number (>1000) of paintings and engravings in a vast array of forms, including hand
stencils and prints; numerous dots, discs, lines,
and other geometric shapes; and figurative representations of animals, including horses, deer,
and birds (24).
We obtained U-Th ages for 53 samples removed
from 25 carbonate formations stratigraphically
1Department of Human Evolution, Max Planck Institute for
Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig,
Germany. 2Department of Archaeology, University of
Southampton, Avenue Campus, Highfield Road, Southampton
SO17 1BF, UK. 3Faculty of Humanities and Social Sciences,
University of Isabel I, Calle de Fernán González 76, 09003
Burgos, Spain. 4Department of Archaeology, Durham University,
South Road, Durham DH1 3LE, UK. 5Ocean and Earth Science,
University of Southampton Waterfront Campus, National
Oceanography Centre Southampton, European Way,
Southampton SO14 3ZH, UK. 6University of Barcelona,
Departament d’Història i Arqueologia (SERP), Carrer de
Montalegre 6, 08001 Barcelona, Spain. 7Institució Catalana
de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys
23, 08010 Barcelona, Spain. 8Centro de Arqueologia da
Universidade de Lisboa (UNIARQ), Faculdade de Letras, Campo
Grande, 1600-214 Lisboa, Portugal. 9Prehistory Section,
University of Alcalá de Henares, Calle Colegios 2, 28801 Alcalá
de Henares, Madrid, Spain. 10Centro de la Prehistoria/Cueva de
Ardales, Avenida de Málaga, no. 1, 29550 Ardales (Málaga),
Spain. 11Quaternary-Prehistory Research Group, I-PAT Research
Group, D. G. Bibliotecas, Museos y Patrimonio Cultural, Junta de
Extremadura, Spain. 12CNRS, Roc des Monges, 46200 St. Sozy,
France. 13Departamento de Historia, Geografía y Filosofía,
Universidad de Cádiz, Avenida Gómez Ulla s/n, Cádiz, Spain.
14Neanderthal Museum, Talstraße 300, 40822 Mettmann,
Germany. 15Institute of Prehistory, University of Cologne,
*These authors contributed equally to this work.
†Corresponding author. Email: firstname.lastname@example.org
Fig. 1. Red scalariform sign, panel 78 in hall XI of La Pasiega
gallery C. This panel features the La Trampa pictorial group (21).
(Inset) Crust sampled and analyzed for a minimum age (64.8 ka),
which constrains the age of the red line. See (20) for details.