Rio Tinto announced last week that the annual Mineral Resources and Ore Reserves tables released as part of its 2016 Annual Report had incorporated some changes to the Argyle Diamonds Mineral Resources. It added that the revised estimates for Argyle are in accordance with the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves, 2012 (JORC Code) and the ASX Listing Rules.

The miner clarified that during 2016, estimated Argyle Mineral Resources exclusive of Ore Reserves decreased by 29Mt from 44Mt to 15Mt. It clarified that the currently reported resources have now been restricted to those parts of the mineralisation which can be potentially developed, mined and processed during the existing mine-life defined by the current underground operation.

The change in due to the fact that, as previously reported, mine life extension options are under ongoing review.

As the change to Argyle Mineral Resources does not impact reported Ore Reserves, this reduction has no bearing on the current mine plan which sees production continuing until 2021.