DRY LAND IN GEOLOGY.* 



By Akthub p. Cousman. 



INTRODUCTION. 



After visits to South Africa, Australia, and India to study dry- 

 land deposits it has become very evident to the writer that most of 

 the earth is covered with water, and also that a ship is the most 

 tantalizing of all modes of travel for a geologist, since captains have 

 a prejudice against an3^thing of geological interest, such as rocks 

 or reefs or shoals. After 1,200 miles of sheltered voyaging behind 

 the great Australian barrier one may reach Java without ever seeing 

 a coral reef at close quarters. Except the oozes dredged from the 

 deep sea and the contours of its bottom revealed by soundings, the 

 three-quarters of the globe beneath the ocean have scarcely any 

 message for the geologist. That the waves and the tides do im- 

 portant geological work is true, but to hear the growl of the breakers 

 and to see them pounce on their prey, one must travel in a small 

 boat close to shore and not in an ocean liner. Even to study the 

 action of the sea on the shore it is better to be on land. The dry 

 shores of Lake Bonneville, as read by a Gilbert, give more instruction 

 in regard to wave work than all the foam and tumult of the surf on 

 the strand. 



The geologist is essentially a land animal, and yet until recently 

 most books on geology, especially textbooks, have had surprisingly 

 little to say of the land and its conditions. The writers seemed all 

 to belong to the blue-water school, so much of their space has been 

 given to the sea and its inhabitants. It is true that continents were 

 mentioned, almost apologetically, when one came to the Cenozoic 

 mammals, but even the Glacial period did not lift geology above the 

 sea for some of the older writers, who preferred icebergs to glaciers 

 for the manufacture of bowlder clay. 



1 Presidential address read before the society Dec. 29, 1915. Reprinted, by permls 

 sion, from Bulletin of the Geological Society of America, vol. 27, pp. 175-192, Mar. 31, 

 1916. 



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