Summary stratigraphic section of thick, prominent Holocene tephra-f...

Summary stratigraphic section of thick, prominent Holocene tephra-f...

Detailed Description

Tephra deposits (referenced by capital letters) found in subalpine meadows near Mount Rainier. Yellow tinted intervals are deposits of ash-sized tephra erupted from Mount St. Helens (MSH). Orange tinted interval is ash-sized tephra from the paroxysmal eruption of Mount Mazama, Oregon, that created Crater Lake. Pink tinted intervals are deposits of pumiceous-to-scoriaceous ash, lapilli, and bombs from Mount Rainier eruptions. Red tinted interval is pumice bearing clay-rich ashfall deposit from the Osceola collapse event; not shown from that event is the layer S directed blast block layer. Gray intervals contain both thin, dark, poorly vesicular tephras from Mount Rainier (not distinguished at this scale), and non-eruptive accumulations of ash-sized sediments reworked from earlier tephra deposits or carried by water and wind from nearby till.

Details

Image Dimensions: 452 x 653

Location Taken: US

Source:


Adapted from Sisson and Vallance, 2009