Test Excavations on the Central Coast

In 2018 OzArk undertook test excavations on the Central Coast to facilitate the expansion of infrastructure necessary for the rapidly expanding population of the area. Test excavations are carried out when the nature and extent of subsurface deposits cannot be determined from the surface survey. Examples could be where the ground surface of a likely landform is obscured by thick ground cover, or an extensive surface scatter is located in an area where soil depth—and hence archaeological deposits—are possible. As a ‘test excavation’, the aim is only to sample an area to see what lies beneath and this, in turn, can then help inform the management recommendations of the project. In the Central Coast example, a surface scatter was located across a broad knoll that had been disturbed by both recreational vehicle use and soil loss from sheet wash erosion. Initially the assessment was that subsurface deposits would be very unlikely due to the soil loss. However, as part of the consultation process, it became evident that the local Aboriginal community were concerned that there could be a subsurface element to the site. In order to have certainty, the client agreed to a one day test excavation program to investigate the site further. Over the course of the day, 18 excavation pits were excavated across all characteristic portions of the site. In the end, only one artefact came from the excavations. While this may seem disappointing, we now are certain that there is no subsurface component to the site and, most importantly, if the site is to be harmed that this harm is not impacting a site of high archaeological values.

Test excavation underway in an area of the site where ground cover does not allow an adequate view of the ground surface to be obtained.
Test excavation normally involves excavating 0.5 m by 0.5 m pits and dry sieving the deposits on site to record all artefacts from that pit.