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XIX. 



STUDIES IN THE PHYSIOGRAPHY AND GLACIAL GEOLOGY OF 

 SOUTHEEN PATAGONIA. 



By E. G. FENTON. 



(communicated by professor ft. A. J. COLE, F.R.S.) 

 [Read Januakv 22, 191S. Publislied March 16, 1921.] 



I. 



General Features of the Region. 



In the present paper I propose to deal with the quaternary and recent 

 geological history of a certain limited portion of Patagonia in which I lived 

 for a period of seven and a half years. The appointment which I held during 

 that time gave me abundant opportunities of visiting the " Camp" generally 

 and studying the superficial features of the country. I was unfortunately 

 never able to visit the country north of the Santa Cruz river to any great 

 extent, or south of the Straits of Magellan ; nor did I ever succeed in getting 

 as far as the chain of the Andes or those most interesting channels or fiords 

 which penetrate the southern cordilleras of Patagonia. However, I found in 

 the eastern plains, even limiting myself to a small portion of their recent 

 history, abundant materials for study. 



This district, lying between the Santa Cruz river and the Straits of 

 Magellan in the one direction, and extending from the Andes to the Atlantic 

 in the other, consists cliiefly of plain or pampa, its level varying from four 

 to five hundred feet along its eastern edge up to perhaps eight hundred or even 

 in places a thousand feet further west. 



If we begin our study by taking a typical portion of the high pampa on the 

 north side of the Gallegos river, the first thing that will strike us (PI. VI, fig. 1) 

 is its extreme flatness of surface. This extraordinary flatness is characteristic 

 of all the eastern plains of Patagonia north of the Gallegos river ; and when 

 travelling through the country the landscape becomes at times almost terrible 

 in its monotony ; not even a single hillock can be seen to break the everlasting 

 evenness of the horizon. 



SCIENT. PROC. B.D.S., VOI.. XVI, NO. XIX 2 G 



