SURFACE SCATTERS OF STONE ARTIFACTS FORM THE BULK of the archaeological record in Australia, yet for all their ubiquity, they continue to pose serious problems for archaeologists. Surface deposits lack stratigraphy in the conventional sense, hence it is difficult to assign them an age and more difficult still to use surface material to demonstrate change. They often represent long periods of deposition and spatial proximity is no guarantee of synchrony. Where artifacts can be dated directly (e.g., the heat-retainer hearths discussed in the example below), hundreds of years may separate spatially adjacent features. Some techniques exist for separating artifacts relating to specific events or occupations (refitting is an obvious example, Close 2000), but such techniques are limited in application and in interpretative potential: the inability to refit artifacts cannot be taken as an indication of great time depth. In the vast majority of cases, it must be assumed that an assemblage from a surface deposit could have derived from more than one, and often many, separate events or occupations.
This poses a problem for conventional interpretations of surface artifact scatters as representative of past settlement systems. As the contributors to the Rossignol and Wandsnider (1992) volume note, simple functional ascriptions applied to surface artifacts scatters gloss over a range of mechanisms by which artifacts are clustered in the landscape. Over a number of years, ethnoarchaeological studies of mobile peoples (e.g., Binford 1978, 1980; O'Connell i987; Yellen 1977) have demonstrated that place use is not constant and redundant. Instead, locations in the landscape may be used by a variety of people, in a variety of ways, and at a variety of times. Thus, archaeological sites are not the same as "residential camps" or "extraction sites"; instead, they are palimpsests--or more correctly "aggregates" (Dewar and McBride 1992), since a palimpsest implies the removal of a previous record (Wandsnider and Camilli 1996)--at best representing remnant settlement patterns that reflect multiple uses over time.
In Australia, there are two main approaches to interpreting the surface artifact scatters that parallel approaches elsewhere in the world (Holdaway and Wandsnider 2004). One is to use ethnographic observations to develop a settlement system approach, obtaining small samples of artifacts from a large number of locations in the landscape and relating these to the natural environment (e.g., in the arid zone, the permanency of water) or the cultural environment (e.g., Ross 1981; Smith 1989, 1996; Thorley 1998, 2001; Veth 1989, 1993). A second approach is to emphasize technology rather than assemblage location, adopting a behavioral ecological approach to artifact form and incorporating a consideration of access to raw material (e.g., Hiscock 1994). A few studies have attempted to combine both approaches (e.g., Barton 2001).
The difficulty of assigning artifacts a date is nullified in these approaches by assuming continuity when technology is stable. Working in the Rudall River region of northwest western Australia, Veth (1993:78) proposes that both settlement location and subsistence behavior are governed by a seasonal pattern of resource exploitation (mainly influenced by rainfall) and a flexible cycle of aggregation and dispersal. Stone artifact assemblage composition is argued to reflect the relationship between occupation duration and water permanency and it is assumed that this human behavioral-environmental interaction remained stable for a long period of time despite indications of considerable environmental variability during the last 7000 years, including a major dry period between 4000 and 2000 B.P. (Veth 1993:9). Veth states:
... to legitimately apply the predictive model here, within an
archaeological context ... it is necessary to assume that the
settlement-subsistence system has remained broadly similar since
the earliest demonstrable date for occupation; in the study area
this is 5000 B. …