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TH E 



AMERICAN JOURNAL OF SCIENCE 



[FOURTH SERIES.] 



Art. XXX VII. — On the Geology of Southern Patagonia ; 

 by J. B. Hatcher. 



It is the purpose of this paper to record such facts relating 

 to the geology of southern Patagonia as were observed by the 

 author during his explorations in that country from May 1st, 

 1896 to June 5th, 1897, while collecting vertebrate fossils for 

 Princeton University ; to offer a few suggestions as to the age 

 and origin of the different sedimentary deposits and their 

 stratigraphic relations to one another as displayed by sections 

 in different parts of the region ; and to make some remarks in 

 regard to the agencies which have determined the present 

 topographical features of the district visited. 



Partly in order to assist others who may visit this country 

 for the purpose of collecting fossils, but more especially for 

 the purpose of facilitating the work of future investigators who 

 may desire either to verify or disprove the correctness of my 

 observations, I present here a sketch map of the Argentine 

 territory of Santa Cruz (see p. 347), on which I have designated 

 the most promising localities for vertebrate fossils observed by 

 myself and my assistant, Mr. O. A. Peterson ; and those places 

 at which the stratigraphical sections accompanying this paper 

 were made. It is believed that with the aid of this map it 

 will be readily possible for anyone to identify all the more 

 important localities mentioned in the text. 



While my observations and conclusions are in many in- 



Am. Jour. Soi. — Fourth Series, Yol. IY, No. 23.— Nov., 1891. 

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