Trachyandesites-porphyritic andesites occur mostly in the southern to western parts of the Sabalan caldera and are associated with pumiceous
Although the Olcese Sand is predominantly a marine unit, the middle part of this unit is nonmarine with lenses of marine deposits and is distinguish by fine- to coarse-grained, often pumiceous
, sandstone with occasional gravel lenses, strong cross bedding, and a bluish-grey color.
greyish brown clay loam; sticky, plastic, very friable; moderately developed 50-100 mm blocky structure; < 0.1%, < 1 mm vesicular pores; few 1-2 mm vertical and horizontal roots; indistinct, discontinuous boundary because of pods of younger pumiceous
tephra from above.
These differences appear related to coarse, pumiceous
soils and steeper slopes on Pine Creek Ridge.