The cave floor is covered with approximately 70 centimeters (28 inches) of soil, a mix of ash from fires, fine aeolian sand and silt, and locally fragmented sandstone and quartzite rocks. Seven horizontal stratigraphic layers have been identified in excavation units in various parts of the cave to date, with generally good chrono-stratigraphic integrity among and between them. Much of the top six stratigraphic units are believed to have been deposited during the past 20,000 years.
However, researchers are convinced that the cave began to be painted much earlier. A slab of painted rock fell to the floor before the sediment was deposited, and adhering to the back of it was a small quantity of ash. This ash was radiocarbon-dated, returning a date of 22,965+/-218 RCYBP, which calibrates to 26,913-28,348 calendar years before the present (cal BP). If the researchers are correct, the ceiling must have been painted before 28,000 years ago. It is possible that the ceiling was painted much earlier than that: radiocarbon dates on charcoal recovered from the base of the deposits from Stratigraphic Unit 7 in that excavation square (with older dates occurring in other squares nearby) range between 44,100 and 46,278 cal BP.
Support for a regional tradition of painting this long ago comes from other sites in Arnhem Land: faceted and use-striated hematite crayons have been recovered at Malakunanja II, in layers dated between 45,000-60,000 years old, and from Nauwalabila 1 at approximately 53,400 years old. Nawarla Gabarnmang is the first evidence of how those pigments may have been used.
Please see the bibliography for sources about Nawarla Gabarnmang.
