Samples of tephra-fall deposit, for component analysis, were taken at seven sites that are roughly 25 km east and northeast of Mount Pinatubo's crater. Sampling 6 months after the eruption, we encountered some difficulty in finding complete and undisturbed sections of the June 15 coarse tephra deposits. Figure 4 . B, Generalized tephra section for Floridablanca, Porac, and Clark Air Base. C, Generalized tephra section for Bamban, Capas, Mabalacat, and Telebastagen.
All materials are pumiceous ash and lapilli, with variations in grain size as shown.
In sections less than 3.5 cm thick, the phenocryst-poor percentage is greater in the bottom interval L1, than in the top interval L2. If subsequent investigations bear out this inconsistency, we would have to conclude that local wind patterns were a factor and that the tephra southwest of the volcano is not strictly contemporaneous with that east of the volcano. Lithics were excluded from percent calculation. We explore three hypotheses for the origin of the two pumice types. At Pinatubo, we have no evidence of gross compositional zonation, but we can imagine some differences in temperature or volatile content of the magma that could have resulted in different textures of pumice.