June 26 (Reuters) - Barrick Gold Corp ABX.TO , the world's No. 2 gold miner, said on Wednesday some assumptions made by Acacia Mining ACAA.L about its mine plans were not supportable and needed adjustments. Mining had on Monday strongly disagreed with majority shareholder Barrick Gold's valuation of the company, saying Barrick's proposal undervalued its life of mine plans and appears to have ignored the value of its exploration and development assets. proposal to take full control of Acacia to resolve a long-standing tax dispute with Tanzania has drawn the ire of Acacia's minority shareholders, who may have the ultimate vote on a deal.