Hey all, maybe this is helpul:
What techniques can be used for fossicking?
Fossicking on land or waters that may be subject to native title is restricted by the terms of the Native Title Act1993 (Commonwealth). Land subject to native title can be taken to be any land other than freehold land, land held under perpetual Western Lands leases and some specific leasehold and reserved lands.
Fossicking can be done on land or waters subject to native title using hand held implements, which include picks, shovels, hammers, sieves, shakers and gold pans. However, regardless of the implements used, no excavation is permitted. On land or waters that are not subject to native title, fossicking is not restricted to hand held implements, but power-operated equipment cannot be used for the purpose of surface disturbance, excavation or processing.
Metal detectors can be used in fossicking activities on any land where fossicking is permitted.
What techniques cannot be used for fossicking? Neither explosives nor dredges can be used in fossicking. Power-operated equipment cannot be used on land or in waters for surface disturbance, excavation or processing. Power operated equipment includes mechanical, hydraulic, pneumatic, battery and electrical equipment or machinery.
Source:
http://www.dpi.nsw.gov.au/__data/as.../A-Guide-to-Fossicking-in-New-South-Wales.PDF