Figure 17. Photographs showing breccias and conglomerate in the Caetano caldera. (A) Large clast of brecciated, Paleozoic quartzite in lithic-rich layer in Caetano Tuff on east side of Toiyabe Range. Layer previously was mapped as conglomerate bed within the Caetano Tuff by Gilluly and Masursky (1965). (B) Mesobreccia sheet in Caetano Tuff on the southwest side of Carico Lake Valley. Mesobreccia composed of angular clasts of siliceous siltstone, quartzite, chert, and chert-pebble conglomerate up to 70 cm in diameter in a more finely clastic, non-tuffaceous matrix. Lens extends several hundred meters along strike. Hammer is 46 cm long. (C) Limestone clasts in Tertiary conglomerate underlying caldera floor near Wenban Spring, Toiyabe Range. (D) Hydrothermally brecciated Redrock Canyon pluton in low hills northwest of Carico Lake. Matrix-supported breccia consists of clasts of Redrock Canyon pluton pervasively altered to kaolinite + quartz in matrix of quartz, Fe-oxide minerals (mostly hematite), and local barite. Note larger brecciated clast in bottom of photo that has hydrothermal matrix filling fracture.