Strategies for¹⁴C Dating the Oxtotitlán Cave Paintings, Guerrero, Mexico

Abstract

Oxtotitlán Cave paintings have been considered among the earliest in Mesoamerica on stylistic grounds, but confirmation of this hypothesis through absolute dating has not been attempted until now. We describe the application of advanced radiocarbon strategies developed for situations such as caves with high carbon backgrounds. Using a low-temperature plasma oxidation system, we dated both the ancient paint and the biogenic rock coatings that cover the paint layers at Oxtotitlán. Our research has significantly expanded the time frame for the production of polychrome rock paintings encompassing the Early Formative and Late Formative/Early Classic periods, statistically spanning a long era from before ca. 1500 cal B.C. to cal A.D. 600.

Micro‐stromatolitic laminations and the origins of engraved, oxalate‐rich accretions from Australian rock art shelters

“…These features, together with the substantial thickness of these accretions compared to similar deposits that have been dated in other parts of the world (Ruiz et al, 2012; Russ et al, 2017; Watchman et al, 2005), suggest slow and undisturbed accumulation over a considerable period of time, making them valuable targets for radiocarbon dating of associated rock art. In sandstone‐dominated rock art provinces such as north‐west Kimberley, this is particularly valuable as the absence of calcite makes the application of the dominant rock art dating method, uranium‐series dating (e.g., Aubert et al, 2014, 2018, 2019; Brumm et al, 2021), much more complex.…”

“…A connection between layered, dark‐coloured, oxalate‐rich accretions and a microbiological depositional mechanism has been previously discussed by studies in both the Kimberley (Ford et al, 1994; Walsh, 1994; Watchman, 2000; Watchman et al, 2001, 2005) and other parts of the world (Beazley et al, 2002; Roberts et al, 2015; Russ et al, 1996, 1999, 2017; Smith et al, 2009; Whitley et al, 2017). Similar accretions are reported growing on ancient stone monuments and buildings of various historical periods (Bonazza et al, 2014; Del Monte & Sabbioni, 1983; Del Monte et al, 1987; Gaylarde et al, 2017; Rampazzi, 2019; Sabbioni & Zappia, 1991), with their formation linked to microbiological processes involving bacteria, lichens, algae and fungi.…”

“…In the Kimberley, the link between the limit of oxalate‐rich accretion formation and areas exposed to direct rain and sunlight was used to identify microorganisms as the critical formation function (Watchman et al, 2001). However, the microorganisms colonising Kimberley rock shelters have not been identified and may include cyanobacteria (Del Monte & Sabbioni, 1983), micro‐stromatolitic algae and fungi (Gadd et al, 2014) or lichens (Russ et al, 1996, 2000, 2017; Smith et al, 2009; and references therein; Watchman, 2000; Watchman et al, 2005), with Gorbushina (2007), suggesting that a collective growth habitat of a combination of organisms is beneficial to the survival of such ‘biofilms’. However, the shaded, frequently damp surfaces in which the oxalate‐rich accretions are found in Kimberley rock shelters may provide favourable microbiological habitats for some organisms, but not others.…”

Chemical characterization and radiocarbon dating of the rock art of Las Charcas caves, Cuba

“…Upon further study, however, the pigment was determined to be bitumen, making the Oxtotitlán mural the first finding of chapapote in prehistoric rock art (Russ et al . 2017). Bitumen was also used as a pigment by the Maya, as observed in analyses of the wall paintings of Bonámpak (Magaloni et al .…”

Conservation State of Two Paintings in the Santa Margherita Cliff Cave: Role of the Environment and of the Microbial Community

“…Therefore, it is crucial to deepen the knowledge about the processes involving deterioration and surface modi cation of such materials. Several studies reported on analyses of paintings to get information about their production and conservation state (Russ et al 2017 physical-chemical and biological approaches have been applied at the same time, together with the environmental monitoring, to get a wide view of the system under investigation. This is an important step in view of the restoration or preservation of the painting as well as the site.…”