Towards an environmental history of the Kimberley region of northwest Australia: Phytolith Analysis at
Carpenter’s Gap 1
Wallis, L.
Department of Archaeology and Natural History
Research School of Pacific and Asian Studies
The Australian National University
Canberra ACT 0200
There are limited numbers of Holocene palaeoecological sites in the northwest of Australia, these being largely confined to the coastal lowlands, and even fewer extending into the late Pleistocene. This situation is principally due to deleterious preservational conditions associated with highly seasonal monsoon rainfall patterns, coupled with the lack of suitable depositional sites to be found in this very old and stable landscape. Hiscock and Kershaw (1992:47) have suggested that archaeological sites, particularly rockshelters, may offer one of the best sources of data relating to the environmental history of the region.
The site of Carpenter’s Gap 1 is located in the limestone reef system of the Napier Range in the inland southwest Kimberley (O’Connor 1995). It provides a well stratified, although compact, cultural sequence extending from the recent past to ca. 40,000 BP, with approximately one-quarter of the deposit having accumulated during the LGM.
Phytolith analysis has been applied to the Carpenter’s Gap 1 sediments as a means of
investigating the vegetation history in the site vicinity. Phytoliths, being silica based microscopic plant fossils, are not subject to the usual processes of decay that tend to destroy organic materials in northern Australian sites. They are, however, significantly different in many aspects to pollen and do not provide the same taxonomic resolution as pollen studies. Taphonomic studies at the site, such as modern phytolith trapping and examination of faecal pellets, have revealed information about the processes of phytolith deposition. These suggest that the grassland component of the assemblage may be largely derived from natural sources, with only minor anthropogenic input. Other phytolith types in the assemblage, such as those that represent the palms and sedges, are probably present as a direct result of human introduction.
Careful assessment of the taphonomic issues relating to phytolith deposition at the site has permitted a general picture of vegetation to be reconstructed. This picture is complemented by the extensive macrobotanic remains recovered from the excavation (McConnell 1997; McConnell and O’Connor 1997), and provides one of the first palaeoenvironmental studies of the region.
References
Hiscock P. and Kershaw A. P. 1992. Palaeoenvironments and prehistory of Australia’s tropical Top End. In: Dodson J. ed. The Naive Lands, pp. 43-75. Longman Cheshire, Melbourne.
McConnell K. 1997. Palaeoethnobotanical remains of Carpenter’s Gap Site 1, the Kimberleys, Western Australia. Unpublished MA thesis, Division of Archaeology and Natural History, RSPAS, The Australian National University, Canberra.
McConnell K. and O’Connor S. 1997. 40,000 year record of food plants in the southern Kimberley Ranges, Western Australia. Australian Archaeology 45, 20-31.
O’Connor S. 1995. Carpenter’s Gap Rockshelter 1: 40,000 years of Aboriginal occupation in the Napier Ranges, Kimberley, WA. Australian Archaeology 40, 58-59.