Kenniff Cave

Australia: The Land Where Time Began

Kenniff Cave

This cave is situated in Carnarvon National Park , Queensland, A tableland of low relief that is dissected by steep-sided valleys in the Central Queensland Highlands. It is 700 m above sea level near the crest of the Great Dividing Range. The region of sandstone cliffs and gorges is rugged, timbered hills and grassy plains. The cave is in Lethbridge Pocket, a sheltered valley, above Meteor Creek. Near the base of the Lower Jurassic sandstone cliffs are formed by the sides of the gorges, the Tertiary basalts that overlie these form a second, higher cliff. Outcrops of 'grey billy' silcrete are present at a number of places throughout the highlands (Finlayson & Webb, in press) in discontinuous layers up to 3 m thick at the top of sandstone that lies immediately beneath the basalt.

Ochre pieces that showed signs of use, scratched, smoothed and with longitudinal grooves were found, but according to Mulvaney & Joyce, 1965:202) "no utilised fragments were found below 4 feet" dated to 4,000 BP (4,130 ± 90 BP; GaK 523). The earliest date obtained at the site was 16,130 +/- 140 BP (NPL 68). (Mulvaney & Joyce, 1965; Mulvaney, 1975).

Kenniff Cave is located on the south bank of Meteor Creek, in a sandstone cliff (fig. 1, Source 3). Silcrete is present beneath the ridge capping of basalt, and silcrete scree has choked part of Meteor Creek near the cave (Mulvaney & Joyce, 1965). There is a silcrete quarry a few metres from the cave.

The Kenniff Cave silcrete, uniform and light grey, with conchoidal fracture surfaces, fine-grained, grain-supported, consisting of sub-rounded to angular fine-sand-sized quartz clasts, that are well-sorted, that have been cemented by syntaxial overgrowths and chalcedony in very thin layers around small voids (Table 1, Fig. 2 (B), Source 3), and microcrystalline matrix of quartz is virtually absent. The fine-grained silcrete at Kenniff Cave is considered to be high quality material that is relatively easy to flake by percussion knapping, that is indicated by the low fracture toughness (median 48 MPa.mm^1/2), that is comparable to Australian flint (median 58 MPa.mm^1/2), and Tibooburra microcrystalline silcrete (median 65 MPa.mm^1/2), (Table 3, Source 3). Kenniff Cave silcrete that is not weathered has a moderate compressive strength, a moderate index of stiffness, and a tensile strength that is considered low, the weathered material has much lower values of all these mechanical properties. The Kenniff Cave silcrete has compressive strength, index of stiffness and tensile strength values that are lower than those of Australian flint and Tibooburra microcrystalline silcrete, though they are much higher than those of medium-grained silcretes found in Australia (Table 2, Source 3). Webb & Domanski (2008) suggest these factors indicate that Kenniff Cave silcrete has enough compression-bending stiffness to maintain the directional stability of fracture propagation. They suggest that during fine retouching there would be a low frequency of step fracture terminations, the small number and size (0.5 mm) of the largest quarts clasts having little effect on the fracture direction.

A 3-part cultural history was revealed by Mulvaney's excavation of Kenniff Cave (Moorwood, 1981, 1984). The core tool and scraper industry, all of which were varieties of flake scrapers, was the earliest phase found. In the mid-Holocene, the appearance of the small tool industry, was a time of proliferation of micro-blade technology and backed artefacts, pirri points, elouras, tula and burren adzes. The recent industry, that was characterised by the Juan knife, though a number of tool types, such as backed artefacts, dropped out of the assemblage.

Throughout the sequence at Kenniff Cave the predominant material used was fine-grained silcrete, referred to as quartzite (Mulvaney & Joyce, 1965) because of its high quality, as well as its close proximity. This lithology is suited to the manufacture of blade scrapers, that are commonly found in the early industry, as well as the blade-based implements from the mid-Holocene assemblages, including tools requiring delicate backing or semi-invasive retouching, as is shown by the mechanical properties of this rock type. The lithology that was used was not affected by the changes that occurred, technological and typological, in the cave deposits, because the versatility of the locally available high quality fine-grained silcrete was sufficient for the manufacture of both flake scrapers and blades/micro-blades.

For more detailed information and illustrations see Source 1

Sources & Further reading