Archean felsic volcanic rocks lenticular fiamme. When hot pumice deposits on a cool surface, it is rapidly cooled, recrystallised and welded into quartz with flame-like ending tips. The eutaxiitc texture represents a hot vapour-phase emplacement of the fragmented volcanic materials on the Earth's surface. Flow bands are present in massive, uniform felsic lava flow units. When the viscous lava flow encounters a surface, friction drags the mobile lava and forms internal banding. Structureless hyaloclastite is commonly found in Archean felsic volcanic rocks. In submarine environments, water quenches and cools lava rapidly during volcanic eruption. The flow is fragmented and form glassy volcanic breccia. The
Musgrave Block and probably also of the Palgrave Caldera is that they represent hot spots along the Musgrave Block where significant magma flux penetrated, formed volcanic calderas with large subvolcanic granite intrusions, and associated mafic volcanism. The relationship of the large granite calderas to the 1050-1080 Ma volcanics has been postulated as one in which the granite calderas were the source for the intermediate and felsic volcanic rocks. The Bentley Supergroup Volcanics are a sequence of bimodal supracrustal volcanic rocks formed during the ~1080 Warakurna Large Igneous Province, and are widely considered comagmatic with the mafic to ultramafic Giles Complex intrusions. The