Fine-grained lacustrine tuffs replaced by alunite: hot spring?
Intense, white altered rock, original host possible feldspar porphyry as suggested by the rectangular cavities of former feldspar phenocrysts
White chalky rock, no obvious original texture noted (hosted in andesite\dacite feldspar porphyry)
White chalky rock, no obvious original texture noted (hosted in andesite\dacite feldspar porphyry
Strong argillic altered rock. Small rectilinear casts, now finely crystalline-aligned, may be relict feldspars
Altered feldspar porphyry breccia (fault?) cemented and replaced by alunite bladed crystals evident on one weathered surface
Brecciated altered tuff\siltstone? cemented by alunite
“vuggy” alunite + silica: original rock totally altered, presence of small quartz shards suggests felsite ash tuff origin