The Ranger Uranium Mine lies within Kakadu National Park in the Northern Territory, Australia. Mining commenced in 1980 and the mine area is must be rehabilitated by 2026, with the hope that it can eventually be incorporated back into Kakadu National Park.
Flowing along the north-eastern side of the mine is Magela Creek whose headwaters are in the Arnhem Land escarpment and flow through Mudginberri Billabong and Magela floodplain to discharge into the East Alligator River.
Currently the alluvial thickness in Magela Creek is generally thought to be 10-12 metres. However investigation drilling and geophysical surveys from the early 1980’s indicated that the bedrock in Magela Creek is some 60 metres below the surface. Since the early 1980s there have been many papers and reports written that provide a confusing picture for these sediment elements of Magela Creek. Much of this confusion is around the relative thickness and distribution of the Holocene and Pleistocene sediments, their lack of discrimination, the different foci of the various studies and the methodologies used.
Associated with this change in interpretation of alluvial thickness, work done in the early 1990s indicated that the current day creeks flowing into Magela Creek were originally several metres above Magela Creek i.e. were waterfalls. Investigation of the logs from nearly 200 boreholes associated with Magela Creek show a number of areas where depth to bedrock is significantly greater than surrounding areas supporting such a concept. If correct, the interpretation of a Magela Scarp (or Magela Fault), often discussed in the late 1970s and early 1980s work but since discounted may in fact also be correct.
This paper, using Magela Creek as an example, explores how historical data, knowledge and information can be misplaced and lost and misinterpretation of more recent information can become accepted as fact.