The dense soil feature found in the Beacon Island mass grave. Paterson and Franklin recorded, ‘Discussions with archaeologists who work with mass burials indicated that the dense soil feature was a rare formation that had not been documented in other contexts (86).’ As part of the research for the survey we read much of the literature related to the wreck and excavations carried out on the island.(When carrying out a HMDS it is valuable to gain an understanding of what material could be found and develop a predictive model for target identification)īob Sheppard from HDA carrying out a HMDS on Long Island for WAMM in 2013įrom this reading HDA discovered that during the 1999 grave excavations on Beacon Island archaeologists observed a ‘dense soil feature’ (Paterson and Franklin 2004:83) and analysis ‘supported visual observations suggesting the soil was in fact dense plant material (85)’. In 2013 HDA (Bob Sheppard and Zack Sheppard) was invited by the Western Australian Museum Maritime to carry out a heritage metal detection survey on historic Beacon and Long Islands. So why does this discovery have implications for Batavia shipwreck research on the Abrolhos Islands? Images from Australian Outdoors magazine November 1966 Warrigal Press archives It is therefore possible the fibrous plant material has built up around the cartridge over 50 years.
This provides us with a Terminus post quem for the shotgun cartridge feature. HDA image.Ī search of vintage Australian Outdoors magazine has revealed that plastic cartridges were introduced in Australia between 19. Older style cardboard 12 gauge cartridges. It was around this time that plastic 12 gauge cartridge cases were introduced and superseded cardboard cartridges. It appears the 12 gauge shotgun cartridge is from the 1960s when locals used the area for clay pigeon shooting. I asked local stakeholders if they knew the origins of any of the cartridge cases located. Not all cartridge cases located by HDA show the same phenomenon which indicates this is not consistent and perhaps relates to soil depth, moisture, nutrients, plant types or other factors. In my view copper deficient plants are attracted to the copper in the cartridge cases and plant competition for access to the metal surface creates the matted ball of root fibres. Indeed, copper is recognised as an ‘essential micronutrient’ although excess copper has a detrimental effect on plant growth (Sheldon and Menzies 2005:341). Copper is added to superphosphate and applied during cropping to rectify the problem. HDA image.įarmers on the coastal plain of Western Australia have long recognised the importance of copper trace elements in the increasing crop yields. HDA image.Ģ0x microscope image of the fibrous roots and sand material. 22 cartridge surrounded by fibrous roots. Shotgun cartridge surrounded by matted plant roots. 22 cartridges (Minelab CTX 3030 Fe Co 11 08 *) found showed similar characteristics (image include). The image below shows a blue shotgun cartridge (Minelab CTX 3030 Fe Co 13 30 see explanation at end) encased with fibrous plant material and a new shotgun cartridge. The material appears to be attracted to the copper in the cartridges. While searching for evidence of the Vergulde Draeck (1656) shipwreck survivors on the Western Australian coast from 2008-2013, Heritage Detection Australia used heritage metal detection and located a number of metal artefacts which may have research ramifications for material found in the Batavia (1629) shipwreck mass graves on the Abrolhos Islands and for archaeologists elsewhere.ĭuring coastal surveys HDA found a number of shotgun and rifle cartridge cases which are surrounded by matted plant roots. Mack McCarthy on The Rise and Demise of the Aus…ĭon findlay on Jean- Paul Turcaud 1940-2020 Geri Lawhon on Jurien Bay to North Head Beach… Katrina Griffith on Mary Lindsay and the Defence o… Gold prospecting with the Pia Wadjarri : a collaborative project.īobshepp on Mary Lindsay and the Defence o….The Rise and Demise of the Australian Prospectors and Miners Hall of Fame.