Rock Art Research

Based on new graphics surveys, several engraved rocks on the right bank of the river Erges associated with two cyclopean shelters situated in its flood bed (Tapada da Foz, Segura, and Foz do Ribeiro das Taliscas, Rosmaninhal) are presented. These occurrences, attributable to recent pre-History, document common recording techniques (pecking and abrasion) and in the case of Ribeiro das Taliscas shelter fine incisions. The shelters, with very irregular surfaces, have multiple petroglyphs, especially inside, where traditional recording techniques are very difficult to apply. The support surfaces are difficult to represent without distortion, and the engraved motifs often offer difficulties of interpretation. To overcome these, we decided to use three-dimensional scanning technology to record the engraved rock surfaces and complement this information with the Morphological Residual Model (MRM), a tool created by one of the authors (HP) that enhances perception of small and faint irregularities. This combination of techniques has great advantages over traditional methods of recording, like efficiency, objectivity, three-dimensionality, versatility and, in particular, greater portability, lower cost and greater speed of execution.