#Pyroclastic #SurgeDeposits of ash and other #tephra in road cut along #CraterLake Highway. These surge deposits sit atop at least 100m of ash, the tops of which are exposed in nearby #Roadcuts.

Near the flanks of former #MtMazama #volcano , the pumice filled existing valleys and created enormous water reservoirs that temper seasonal cycles to support local hydrology year round.

The contrast in #eruption style is evident between these two proximal exposures.

#Geology #Rocks #Oregon #PNW