194 J. C. BRAXXEE OUTLINES OF THE GEOLOGY OF BRAZIL 



It has been one of th.e greatest pleasures of my life that I have been 

 able thus to contribute something to the knowledge of the geology of the 

 country in which I began my professional career. 



After a life spent chiefly in active geologic work and in the direction 

 of such work. I should be remiss in my duty to Brazil if I did not use 

 this occasion to urge on Brazilian statesmen the serious necessity for the 

 active encouragement and support of scientific geologic work on the part 

 of the national and state governments. Kjiowledge must precede the 

 application of knowledge in geology as well as in other matters: and 

 unless the development of the country's mineral resources be based on 

 and proceed from a scientific knowledge of its geology, there must inev- 

 itably be waste of effort^ loss of monev. and the delay of national progress 

 inseparable from haphazard methods. 



The available Data 

 in gexebal 



Our knowledge of the geology of Brazil has hitherto been so frag- 

 mentary and uncertain that the generalized geologic maps thus far pub- 

 lished have failed to furnish any clear conception of the geology of that 

 country as a whole. 



Many of the uncertainties, however, are not due to the lack of data, 

 but rather to a lack of acquaintance with and coordination of data. By 

 bringing together everything known and published on the geology of 

 Brazil, and by seeking a rational interpretation of the available facts, it 

 has been found possible to represent the general geolog}' of the country 

 fairly well. There are necessarily many and large areas about which 

 little or nothing is known, and there are many questions about the ages 

 and correlations of the rocks, their precise distribution, their structural 

 details, and their mineral resources, that must go unanswered for the 

 present or be answered only tentatively ; but such doubts and uncertain- 

 ties are inseparable from all progress in scientific work. 



One who knows little or nothing of the difficulties of gathering geologic 

 information in the field in Brazil may be disposed to place too low an 

 estimate on the amount and character of the information shown on the 

 map. But it should be kept in mind that the country is enormouslv big 

 and, on the whole, but thinly populated ; that vast areas therein are not 

 yet penetrated by railways; that there are as yet but few good wagon 

 roads in the country : and that the difficulties of travel and transportation 

 in parts of the country remote from railways and navigation are not onlv 

 serious, but sometimes almost insuperable. 



