National Geographic : 1913 Feb
only from the deposits which fell at distances greater than 15 miles from the mountain. If streams 2' of lava flowed out, they did not come within sight of the coast. o The deposits which were studied in detail vary in thickness from 55 inches at the head of Amalik Bay, 152 miles from the moun 5 tain, to 32 inches at the east end .. of Afognak Island, 113 miles z from the volcano. S Throughout this entire district, §S Eat least three layers correspond S ing to the three major outbreaks Scan be observed. The bottom So layer is of relatively coarse gray o " material; the middle layer is finer and is brown, and the upper S layer is the finest and is light Gray or almost white. Each layer Decreases in thickness with the • distance from the volcano, the S decrease being most marked in a the bottom and middle layers w (see pages 132 and 176). S The bottom layer consists of > .fragments of pumice mixed with w | a small proportion of fragments Sof crystals of feldspars and py o roxenes and other dark minerals. ' The pumice is consolidated lava " froth, mostly white, and varies in " size from pieces I or 2 ounces in < . weightand2or3inchesinlong Sest dimension, which fell 15 miles From the volcano, to material of Sthe grain of fine sand, which fell S70 to Ioo miles away. C The middle or brown material Near the base of the mountain Consists of several layers, which Z O differ from the lower bed in con Staiing a smaller proportion of 0 4 crystalline material and in con . taining a considerable amount of O yellowish and brownish pumice. 1 Z At distances of 70 to 80 miles S from the mountain this material S consists of two brown layers, the lower one of sandy grain and the o upper of very fine dust. At dis § tances of 90 to Ioo miles from z the mountain only a single layer could be recognized, and that was composed of impalpable brown dust.