The Palaeoproterozoic Warramunga Formation is notable as the
host to the enigmatic, so-called 'Tennant Creek style'
mineralisation. These polymetallic (but mainly Au-Cu-Bi) ore
deposits typically have a close spatial association with massive
ironstone bodies, and frequently also with banded ironstone,
known locally as 'haematite shale'. The Warramunga Formation is a polydeformed, turbiditic
succession. Partial, or complete Bouma sequences variously
comprising lithic arenite, wacke, siltstone, and mudstone
constitute a classic flysch sequence deposited as a proximal
(sandstone lithofacies) to distal (siltstone lithofacies) fan
association. The Warramunga Formation has a substantial component of
volcanic detritus and has generally been attributed to an
essentially contemporaneous volcanic provenance. However,
lithostratigraphic revision (Donnellan, Hussey and Morrison, in
press) apparently precludes outcropping volcanic rocks of the
Tennant Creek Block, or indeed Inlier, as the source of detritus. Warramunga Formation geochemistry indicates rapid
derivation from a fractionated, predominately felsic igneous
source (Palaeoproterozoic upper crust) with a minimum of
chemical weathering; together with an admixture of mafic
material. Warramunga Formation geochemistry cannot, however,
be reconciled with that of the Bemborough Formation, which is
here taken to be representative of Flynn Subgroup felsic volcanic
rocks. Similarly, the Warramunga Formation is geochemically
distinct from Flynn Subgroup sedimentary rocks. Geochemistry
of the banded ironstone is consistent with its interpretation as
Dine-grained turbidites.