An interesting thing: the heterogeneous #tephra were erupted during a period of strong #strombolian activity, sometimes producing spectacular shock waves. Is there some relationship between both?
For more detail, see our full publication. It is #OpenAcess!

https://www.youtube.com/watch?v=Sx_b1ED2bk8&ab_channel=Buddy

Arias et al present a sediment core record from a maar in the Eifel volcano field in central Germany that securely dates the Elsterian glaciation to MIS 12, and the Holsteinian interglacial to MIS 11. Based on the tephra dates and annual layer counting, they constrain the MIS 11 interglacial optimum to be between 395-421 thousand years ago #PaleoClimate #IceSheets #ClimateChange #SedimentCore #Tephra https://www.sciencedirect.com/science/article/pii/S0921818123001169

#Geology #Volcano #Rocks #Tephra #GroundIsLava #Oregon #Cascades #BonsaiSoil

Panoramic view across central vent of Little Nash Crater near Santiam Summit in Oregon. Center of vent characterized by bright red scoria while the flanks show 1” and smaller dark gray to black scoria…this is one of the primary quarries of cinder used to “sand” highways in Central Oregon during the winter.

The black scoria is somewhat rare and prized for use in #bonsai #soil in Oregon…combined with pumice and clay.

#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