Income Tax Assessment Act 1997
Land that you *acquire on or after 20 September 1985 that is adjacent to land (the original land ) you acquired before that day is taken to be a separate *CGT asset from the original land if it and the original land are amalgamated into one title.
On 1 April 1984 you bought a block of land. On 1 June 1999 you bought another block of land adjacent to the first block. You amalgamate the titles to the 2 blocks into 1 title.
The second block is treated as a separate CGT asset. You can make a capital gain or loss from it if you sell the whole area of land.