Preliminary geological assessment with proposals for systematic exploration, Finniss Range Project

Abstract

The Finniss Range Project area has major economic potential for Sn, Ta, Nb mineralisation both within the primary pegmatite hosts as well as derived secondary alluvial deposits. This assessment is based on field visits and evaluation of production records and prior exploration data. Recognition of structural controls of mineralisation in the 'pegmatite lodes' has greately enhanced economic potential of these multiple deposits. The distribution of pegmatite deposits is considerably more widespread than previously recognised, and the intensity of mineralisation is intimately related to late stage hydrothermal alteration. There is some evidence that the degree of alteration is related to the size and dimention of the pegmatites, which are in turn influenced by structure. It is postulated that the two major transcurrent faults within the Project area, controlled the emplacement of the pegmatites by a process of structural dilation. Conceptual models suggest a possibility for moderate size 'pipe-like' pegmatitic ore bodies centred on favourable structurally dilated zones. Similarly thepresence of probable late Cainozoic palaeoplacer deposits, and a stratigraphy comparable to the Wolverton and Sundaland tin fields, indicates that the undifferentiated sediment fill has a high potential for a major alluvial Sn-Ta-Nb resource.