Figure 12. Typical colors of lapilli layers and interbedded ash in tephra set M 9 km east of Mount St. Helens. Yellowish-brown pumiceous layers Mm and Mp in the upper part of the set are separated by brown ash. Tephra layers Mc, Mo, and Mg lower in the set are separated by purplish-gray to purplish-brown ash. Ice axe is shown for scale. Photograph taken in 1971.