The Palaeo- to Mesoproterozoic McArthur Basin contains a thick
(-10 km) intracratonic platform cover sequence of
unmetamorphosed and relatively undeformed sedimentary and
volcanic rocks (Pietsch et al, 1991). It covers an area exceeding
180 000 km2 of the North Australian Craton (Figure 1), overlying
segments of the older deformed basement and transitional
igneous units. Volcanism in the basin (including transitional
domain) followed a four-phase pattern. These phases are
geologically distinct and widely distributed, and are also
recognised beyond the McArthur Basin in many similar-aged
tectonic provinces in northern Australia. The four phases are
described briefly below. Regional and structural nomenclature
used refers to Figure 1. A stratigraphic correlation diagram is
presented in Figure 2.