Geology, mineralisation and exploration strategy, Pine Creek Inlier

Abstract

Sedimentation in the Pine Creek Inlier occurred during two main periods and each period was followed by metamorphism and deformation. Although, the second period of sedimentation may have been started in tensional regime, it is likely that compression and associated deformation began midway through the second sedimentary period, and continued during subsequent regional metamorphism. The effects of this compressional deformation were locally modified above and around rising diapers of granitic Archaean basement. The relaxation of compression allowed some rising sialic basement to melt, forming younger granite plugs. Some magma continued to rise and spread, resulting in extensive granite sills. Uplift and erosion was followed by the deposition of Middle Proterozoic sediments. Gold and base metal mineralisation occurred during sedimentation and compressional deformation. Possible interaction with hydrocarbons determines the style of deposits formed. Gold mineralisation also continued after the relaxation of compression and during the sedimentation of the overlying Middle Proterozoic. The techniques used o recognise the position of diapiric basement and the close association between this and a number of different metal deposit types are tested in different mineral provinces.