Scientific Results of the Katmai Expeditions of the 

 National Geographic Society. 



XII. THE GREAT MAGEIK LANDSLIDE. 



Robert F. Griggs. 



When in our exploration of the Katmai District we entered 

 the upper reaches of Martin Creek, we came upon a most 

 curious terrane, a third wonder almost worthy of being ranked 

 with the Ten Thousand Smokes and the crater of Katmai.. 

 The valley was filled with a stupendous mass of broken up rocks,, 

 piled together in the utmost confusion, so different from any 

 of the common physiographic features that its interpretation 

 for a time seemed an insoluble riddle. 



The upper portion of this Valley, for five miles from its head 

 out on to the flat plain, where it is more than a mile wide, is 

 covered with a great mass of debris. Piles of broken rock, 

 chunks of soil, masses of peat and plant remains are everywhere 

 jumbled together in indiscriminate heaps. The bowlders 

 comprise several sorts of rock; fragments of an old lava flow^ 

 tuff from an ancient eruption, and blocks of sandstone are all 

 mixed together. 



BOWLDERS AS BIG AS A HOUSE MORE THAN A MILE FROM 



THEIR SOURCE. 



Rocks ten feet across are abundant, and in some places, 

 compose the bulk of the terrane, while much larger bowlders are 

 frequently encountered, some of them as large as a good sized 

 house. Many measure more than 30 or 40 feet. The largest 

 single stone observed was 75 feet long, 35 feet wide and 20 feet 

 high, lying half hidden in the surrounding debris. (See page 

 326). 



The mass is spread so thinly over the valley floor as appar- 

 ently to change but little the original contours. Its general 

 surface is fairly flat, conforming with that of the broad open 

 U-shaped valley in which it occurs, but it is thickly studded 

 with curious conical mounds of detritus which contribute much 

 to its puzzling appearance. (See page 352). In the lower part 



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