Geology. — ''Observations on the Incandescent Sand Floio of the 

 Volley of ten thousand smokes." By Robert F. Griggs. 

 (Columbus, Ohio, U.S.A.) 



(Communicated at the meeting of April 29, 1922). 



Of the work done by the last expedition (1919) Dr. Escfikr has 

 seen only the popular account in the National Geographic Magazine, 

 September, 1921, Vol. 40 pp. 219—292. This account, written for 

 the 725,000 members of the National Geographic Society, was mani- 

 festly not the proper place for a technical presentation of the detailed 

 data which the geologist requires as the basis for his conclusions. 



A more technical, though only preliminary, account giving more 

 geological information has been published by Dr. C. N. Fenner, 

 Petrologist of the cooperating party sent with the expedition by the 

 Geophysical Laboratory of the Carnegie Institution, in the Journal 

 of Geology, Vol. 28, pp. 569—606, 1920, under the title "The 

 Katmai Region, Alaska, and the Great Eruption of 1912." 



A further contribution by E.T.Allen, Chemist of the Geophysical 

 party, dealing not directly with the Incandescent Sand Flow but 

 with the "Chemical Aspects of Volcanism", appeared in the Journal 

 of the Franklin Institute, Vol. 193, pp. 29—80, January, 1922. 



Further papers giving the scientific results of the Katmai expedi- 

 tions in more detail are soon to appear in the projected Memoirs 

 of the National Geographic Society, 



Dr. Escher believes that the hot sand flow was made possible by the 

 water of a crater lake which "must have" occupied the top of the 

 mountain prior to the Eruption of 1912. He is in fact so sure of 

 such a lake that he even figures it on his diagram. 



The first and most obvious fact which renders this explanation 

 impossible is that Katmai possessed no crater lake prior to the 

 eruption. On page 43 is reproduced a section of the United States 

 Coast and Geodetic Survey Chart N'. 8555 showing the condition of 

 Katmai before the great eruption. It was a three-peaked mass without 

 any large crater, essentially similar to its near neighbor Mageik, see 

 map on page 45 also a photograph reproduced in the National 

 Geographic Magazine, Vol. 31, p. 30, 1917, Both were rounded 

 domes built up by repeated flows of viscous lava without admixture 

 of cinders or other fragmental products such as appear in the typical 

 composite cone. 



