Ann: Corporate Presentation - July 2019, page-21

I don't think so.
Here's an extract from the Sept 18 quarterly report.
"Mt Cattlin reported an average cash margin per dmt sold (including royalties and marketing fees) of US$411 for the quarter, a reduction from the previous quarter, primarily due to higher unit costs of production arising from lower production."
GXY did not report these costs (the ones you say are US$92 per ton) as a separate line item. I have checked previous reports and have not seen this number mentioned anywhere else.