Appendix C - Cultural Heritage Impact Assessment - Peabody Energy

Cultural Heritage Impact Assessment
North Wambo Underground Mine Modification
3.0 Environmental Context
An understanding of environmental context is important for the predictive modelling of Aboriginal sites, as
well as for their interpretation. The local environment provided natural resources for Aboriginal people, such
as stone (for manufacturing stone tools), food and medicines, wood and bark (for implements such as
shields, spears, canoes, bowls, shelters, amongst others), in addition to areas for camping and other
activities. The nature of Aboriginal occupation and resource procurement is related to the local environment
and it therefore needs to be considered as part of the cultural heritage assessment process. The reporting of
environmental context is required under the Code of Practice.
3.1 Geology
Aboriginal people often made stone tools using siliceous, metamorphic or igneous rocks and therefore
understanding the local geology can provide important information regarding resources in a project area.
The nature of stone exploitation by Aboriginal people depends on the characteristics of the source, for
example whether it outcrops on the surface (a primary source), or whether it occurs as gravels (a secondary
source) (Doelman, Torrence et al. 2008).
Most of the project area is characterised by the Late Permian Singleton Supergroup which is part of the
Permian Singleton Coal Measures (sandstone, shale, mudstone, conglomerate and coal seams)
(Department of Mines 1969). The surface geology of the project area is predominantly the Wollombi Coal
Measures in the south-west and Denman Formation of the Wittingham Coal Measures in the north.
Quaternary alluvial silt and sand deposits dominate most of the eastern part of the project area, along the
flats of Wollombi Brook. The Wollombi Coal Measures comprise coal seams in association with
carbonaceous shale, siltstone, sandstone and tuffaceous claystone (Department of Mines 1969). The
Denman Formation of the Wittingham Coal Measures also consists of coal seams and claystone, tuff,
siltstone, sandstone, conglomerate and sandstone siltstone laminate (Sniffin, McIlveen et al. 1988).
Generally, the late Permian Wollombi Coal Measures overlie the Wittingham Coal Measures, which in turn
overlie the mid to early Permian Maitland Group. The Maitland Group in turn overlies the early Permian
Greta Coal Measures which are underlain by the Dalwood Group. These strata layers form the Singleton
Super Group. There is evidence of volcanic activity in the area including felsic volcanics, fault lines and a
number of dykes (Sniffin, McIlveen et al. 1988).
The presence of sandstone in the project area is important for Aboriginal occupation as sandstone was
commonly used for grinding stone artefacts. Overhangs and caves in sandstone cliffs and boulders below
the cliff line were sometimes used for shelter and may be found in the sandstone escarpment to the south
west of the project area. Rock engravings and grinding grooves may be found in areas of exposed
sandstone and sandstone outcrops particularly along creek beds in nearby creek lines such as Wollombi
Brook or North Wambo Creek. Raw materials in the local area including silcrete, indurated mudstone and
silicified tuff, as well as chert, basalt, rhyolite and petrified wood were commonly used by Aboriginal people
for manufacturing flaked stone tools. The softer shales and claystones are highly susceptible to water
erosion processes and are generally unsuitable for the manufacture of stone tools.
3.2 Soils
The predominant soil landscape in the immediate project area is consistent with the Bulga soil landscape,
which consists of smooth slopes forming undulating rises. The Bulga soil landscape is characterised by
sandstone colluviums, yellow and brown solodic soils and brown earths on the lower slopes, with yellow
soloths on the mid slope and upper slopes. Minor to moderate sheet erosion is common (Kovac and Lawrie
1991:125-128). Aboriginal objects may be found in these gently sloping areas.
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