Sandstone weathering processes in the painted rock shelters of Cerro Colorado (Córdoba, Argentina)


Peña-Monné, J.L., Sampietro-Vattuone, M.M., Báez, W.A., García-Giménez, R.,   Stábile, F.M., Martínez Stagnaro, S.Y., Tissera, L.E., 2021. Sandstone weathering processes in the painted rock shelters of Cerro Colorado (Córdoba, Argentina). Geoarchaeology, 2021, 1-18.  





Tafoni, produced by physicochemical weathering of sandstones, are abundant in the
Cerro Colorado (Córdoba province, Argentina). Many of the rock shelters are decorated
with rock art of high heritage significance. This art belongs to semisedentary
communities from the Late Prehispanic Period (ca. 1550–350 AP). They include
morphologies inherited from more humid ancient climates combined with current
weathering processes. Evolutionary relief study established that tafoni formation is a
product of inherited past wetter climates. Mineralogical and petrographic analyses
were performed on samples collected from the sandstones and from various
morphologies, weathering residues, and wall and ceiling concretions at four rock
shelters, Cueva del Indio, Ricci, Quitilipi, and La Trampa. Gypsum and other salts that
are not part of the unaltered rock but the result of weathering reveal the magnitude
of hydroclastic and haloclastic processes. These activities form active granular disintegration,
flaking, and spalling, and impinge on some painted panels. Mapping the
distribution of weathering features and processes at each rock shelter enables the
planning of interventions to mitigate and alleviate the effects caused by infiltration
of water through rock discontinuities, fractures, and overhangs. It also allows decreasing
the accumulation of dust and minimizing muddy water flowing over the
paintings. These actions are aimed at retarding the progression of rock art degradation
and the visible loss of some paintings.