Figure 11

Figure 11. Lower part of tephra set C at the Muddy River quarry site, 11 km east of Mount St. Helens (measured section C-2). Scraped part of outcrop shows about 100 cm of layer Cb over colluvium that lies on bedrock; a brown oxidation profile extends 30-40 cm down into layer Cb from its top. Layer Cb is overlain by (1) gray ash and lapilli of layer Ct, (2) yellow-brown pumice of layers Cw and Cm, and (3) gray-brown ash that lies between layers Cm and Cy (layer Cy was not dug out here). Shovel is approximately 100 cm long. Photograph taken in 1979.