National Geographic : 1892 May 15
148 .W. Hayes-Expedition through the Yukon District. As described by Dawson * from the Yukon, " It is a fine, white, sandy material * * * consisting chiefly of volcanic glass, * * * the greater portion of which has been drawn out into elongated shreds, frequently resembling the substance known as 'Pele's hair.'" Where first noticed between the Nisling and Kluantu it had the appearance of sand which results from the disintegration of a rather coarsely crystalline marble, the indi vidual fragments being from 0.5 mm to 1 mm in diameter. The average dimensions increase to the westward, and in the Klutlan valley the deposit contains many fragments of white vesicular pumice from two to ten centimeters in diameter, though the greater part is much finer, perhaps from 1 mm to 5 mm in diam eter. Nothing in the nature of true volcanic bombs was seen in the tufa, though their presence may have been overlooked. Taking the approximate limits of the deposit, as observed on the Yukon by McConnell, on the Pelly and Lewes by Dawson, and on the Teslin and at Scolai pass by the writer, it will be seen to cover an oval area, with the maximum thickness near the western extremity. The oval area (which is depicted on plate 18) is about 370 miles from east to west and 220 from north to south, or about 52,280 square miles. Assuming the deposit to be in the form of a flat cone with the above base and a vertical height of but fifty feet, its volume amounts to 165 cubic miles of material. From the facts of distribution, as above stated, a fairly safe inference may be drawn as to the source of the deposit. The explosive eruption which produced the tufa probably occurred in the northern part of the St Elias mountains, near the source of Klutlan glacier. As already stated, it was impossible to tell whether there is any present volcanic activity in this region. One conspicuous peak, of which the top remained hidden by clouds, was pointed out by the natives as having some unusual characteristics of which they seemed to stand much in awe. The name by which they called the mountain was Nat-azh-at, mean ing, as near as I could make out, " shape of a man; " but, owing to native reticence and lack of an interpreter, it was impossible to obtain any satisfactory information concerning the mountain. Mount Wrangell has been suggested as the source of the tufa, * Report of an exploration in the Yukon district, N. W . T ., and adja cent northern portions of British Columbia, 1887; Ann. Rep. Geol. Surv. Canada, Montreal, 1889, p. 46B.
1893 Feb 08
1892 Mar 31