Ancient artists and their materials
The rocks at Naula Lena display a gallery of prehistoric art, featuring a mix of geometric shapes, dots, lines, and depictions of human and animal figures. The artists created a surprisingly durable paint, which in well-preserved areas forms a thick paste between 0.5 mm and 2 mm thick. This suggests a deliberate and controlled application process, likely using a brush-like tool to create the varied line thicknesses seen in the artwork. The limited color palette is typical of such ancient sites, primarily consisting of dull red, yellow, and black.
The primary pigment identified in prehistoric Sri Lankan art is ochre, an iron-rich clay earth pigment. The most important coloring component of ochre is hydrated iron oxide. The specific shade depends on its chemical composition; red ochre is derived from hematite, while yellow ochre comes from goethite. Analysis of pigments from various Sri Lankan sites confirms a strong link between the processing of ochre and the production of red and yellow paints. This material was used for art; mineral ochre was also ground to produce colored beads for personal adornment as far back as 45,000 years ago in other parts of Sri Lanka.
Prehistoric paint production
The creation of the paint at Naula Lena was a multi-step chemical process. The artists began by sourcing and processing iron-rich minerals. The ochre was ground into a fine powder, a technique seen at prehistoric sites globally for over 100,000 years. This powder then needed to be mixed with a binding agent to make it adhere to the cave walls. While the exact binders at Naula Lena require further specific analysis, ethnographic parallels and the paint's durability point to the use of plant-based liquids or animal fats. For example, some tribal groups in Australia have historically used orchid juice as a fixative for their ochre paints.
This process demonstrates a sophisticated understanding of material science. The creators knew which local minerals would produce specific colors and how to process them. They also understood that the powdered pigment alone was not enough and required a binder to create a lasting paint. This ability to follow a consistent recipe to create a compound implies complex cognition and the capacity for abstract thought. The result is a form of art that has survived for millennia, showing the technological and cognitive world of Sri Lanka's earliest inhabitants.