From the SEC Filing:
"5. Argonaut is responsible for paying all land taxes, annual concessions or permit fees and the monthly lease of US$1,000 during the term of the Agreement. In addition, prior to July 6, 2016, Argonaut must expend a minimum of US$600,000 in expenditures relating to drilling Reverse Circulation and/or Core or a combination of both drill holes in relation to the Mining Concessions."
Is the "mining tax" you're referring to a "land tax"? If so, Argonaut will pay it.
Dino