Ann: Quarterly Cashflow Report, page-137

Corps Act does not apply.....FIRB Policy and Foreign Acquisitions and Takeovers Act applies.

Have a look at the FIRB Guidance Note on this topic: https://firb.gov.au/resources/guidance/gn24/

I don't know whether the tenements are still exploration licences or mining tenements. If the former then you are probably correct re FIRB not being needed, it the latter, then:

"Under the foreign investment framework, a mining or production tenement is a type of Australian land. Acquisitions of interests in a mining or production tenement by foreign persons are notifiable and significant actions (regardless of the value — that is, a $0 threshold applies), except if acquired directly from an Australian government."

Cheers and goodluck!