Chert bifacial Northern Territory Triangular Point from Mundogie Hill, Kakadu, Arnhem Land, in the Northern Territory. Bifacial points are from the Late Holocene in Australia, after ca. 5000 BP, and were made into the the recent past.
This point was made on a flake. It was thinned bifacially along one edge and unifacially along the opposite edge. The edges were then shaped by non-invasive flaking, probably using a percussion technique. Northern Territory Triangular Points are mainly found in southwestern Arnhem Land. They were made in prehistory but not historically; no hafted examples are known to exist.
See the annotations for technological details about this stone tool.
Archaeologists often divide points into unifacial and bifacial variants. Unifacial macroblade points are usually retouched towards the dorsal surface to create the distal point and shape the edges, with unifacial or bifacial flaking at the proximal (platform) end to thin and shape it for hafting. Bifacial macroblade points are retouched to both faces along both margins. Macroblades were sometimes shaped in certain ways to produce regionally-specific tool types, such as Juan knives in Queensland and Yilugwa knives in Central Australia. Large-sized Pirri Points were sometimes made by pressure flaking on macroblades.
Some archaeologists think that unifacial points turned into bifacial points through resharpening. This may have been true in some cases, but the narrow width of macroblades does not allow for the type of bifacial thinning seen on, for instance, Kimberley Points or Northern Territory Triangular Points. Other bifacial points, such as Wanji Bifaces and some bifacial points in western Queensland, were made on tabular pieces of raw material and not macroblades.