The Litchfield complex, north-west northern territory: Archaean basement or Proterozoic cover?

The south-eastern part of the Litchfield Complex in the Northern Territory has two distinct metamorphic units, both containing mafic and metasedimentary members. These are intruded by gabbros, ultramafics, and anatectic granitoids. Superficially there is a correlation between these metamorphic units and the adjacent, compositionally similar, low grade rocks in the Pine Creek Geosyncline to the E. It is proposed, however, that the two metamorphic units are not corelatives because their metamorphic and deformational histories are markedly different, nor do they relate to the low grade rocks to the E. The most intensely deformed, metamorphic unit could also be allocthonous to account for its complex history. On the basis of recent work in the Pine Creek Geosyncline, it is proposed that the allocthonous unit is Archaean basement which was involved in westward thrusting of parts of the geosynclinal sequence (the Burrell Creek Formation). The least deformed of the metamorphic units may equate to older units in the geosyncline. A correlation between the Litchfield Complex and the Early Lamboo Complex of the Halls Creek Province is made.