Noble Metal Concentrations in Selected Komatiitic and Tholeiitic Archean Volcanic Rocks from Munro Township, Ontario

Abstract

<p> The Au, Pt, Pd and Ir content of Fred's flow (a layered komatiite flow), Theo's flow (a layered tholeiite flow) and two peridotitic komatiite flows at Pyke Hill, all from Munro Township, were determined using radiochemical neutron activation analysis. In addition, the potential of Pyke Hill peridotitic komatiites as a gold source was evaluated. X-ray fluorescence spectroscopy, atomic absorption spectroscopy and a Leco automatic carbon determinator were used to determine major and trace element content in a total of 43 samples. </p> See Chart in text. <p> The peridotitic komatiite magma at Pyke Hill has the most mantle like proportions of Pt and Pd. None of the flows studied have been saturated with respect to sulphur. No leaching of siderophile and chalcophile elements has taken place prior to extrusion and cooling.</p> <p> The low gold content of the unaltered Pyke Hill peridotitic komatiites (average 2.8 ppb) do not make them obvious source rocks for gold deposits. </p>