New research by academics from the University of Leicester and the British Museum working with colleagues from the British Geological Survey and Cambridge University, outlines the science behind the largest concentration of indigenous pre-Columbian rock art in the Caribbean.

Exploration and surveys of around 70 cave systems -- part of an interdisciplinary study of past human activity on Puerto Rico's Mona Island -- revealed that Mona's caves include the greatest diversity of preserved indigenous iconography in the Caribbean, with thousands of motifs recorded in dark zone chambers far from cave entrances.

Published by the Journal of Archaeological Science, the paper is entitled 'Artists before Columbus: A multi-method characterization of the materials and practices of Caribbean cave art'.

Written by a collective of academics, including Dr Alice Samson (University of Leicester) and Dr Jago Cooper (British Museum), the paper is the result of three-years of research from 2013 to 2016, on the currently uninhabited and remote Mona Island in the Caribbean.

The paper presents the results of National Geographic funded fieldwork by an Anglo-Puerto Rican team, who uncovered extensive and undocumented rock art deep inside the islands labyrinthine cave systems. The paper presents the first results of the dating of the art, as well as insights into the artistic choices made about location, technique, and paint recipes of the time.

Dr Alice Samson, co-author of the paper from the University of Leicester School of Archaeology and Ancient History, explains: "Scientific analyses from the team have provided the first dates for rock art in the Caribbean -- illustrating that these images are pre-Columbian made by artists exploring and experimenting deep underground.

"The conservation-minded approach we used squeezed every bit of information we could out of the discovery using multiple methods that are relevant to the studies of vulnerable rock art worldwide."

Dr Jago Cooper said: "For the millions of indigenous peoples living in the Caribbean before European arrival, caves represented portals into a spiritual realm, and therefore these new discoveries of the artists at work within them captures, the essence of their belief systems and the building blocks of their cultural identity."

The team uncovered multiple rock art sites inside the caves with iconography consisting of human, animal, and meandering designs. Some are painted or drawn, and others, drawn with the fingers in the soft walls, are more elaborate and akin to a technique called finger-fluting familiar from Palaeolithic rock art in southern Europe.

The team also included students from Puerto Rico and the UK carrying out dissertations in Climate Science, Archaeology, and History.

Victor Serrano, member of the student team and PhD distance learning student in the University of Leicester's School of Archaeology and Ancient History, said: "As a Puerto Rican these groups of people that visited and lived in Mona Island are my ancestors, and their story is of utmost importance. Working in those caves, as part of the Corazon del Caribe archaeological project, is hard but fun work.

"Most of the precolonial pictographs are in very narrow spaces deep in the caves, some are very hard to access, you have to crawl to get to them, they are very extensive and humidity is very high but it is extremely rewarding. Imagine a social networking site, where instead of having a page with posts of people here you have an actual cave wall or roof full of different pictographs."