THE EXISTENCE AND CONFIGURATION OF 

 PRECAMBRIAN CONTINENTS 



BY RUDOLF RUEDEMANN 



Introduction 



Paleogeography has, both in Europe and America, become a 

 recognized branch of science that is fundamentally based on facts 

 furnished by stratigraphic and paleontologic investigations and that 

 also receives valuable information from the recent distribution of 

 the organic world. 



Precambrian geology has thus far been drawn upon but in- 

 cidentally, and nowhere, to the author's knowledge, in a systematic 

 way. As a result the series of paleogeographic maps of either the 

 world or of one of the hemispheres or continents, that have been 

 published in the last score of years — ■ and that have done so much to 

 broaden our conception of the development of the face of the earth — 

 have all stopped short at the Lower Cambrian. 1 



The cause for this failure to go beyond the beginning of the 

 Cambrian into the vast and dim Precambrian era is readily seen in a 

 whole number of perplexing problems that at once arise if one 

 attempts to push the inquiry into the metamorphosed and non- 

 fossiliferous rocks. To cite only a few of these : the distinction in 

 these Precambrian beds of originally marine and terrestrial, deep-sea 

 and continental formations; the almost uniformly and intri- 

 cately folded and foliated, faulted and injected nature of the beds, 

 which apparently is so irregular as to furnish no directive lines; 

 and further the uncertainty as to the correlation of the various 

 series distinguished on the different continents. 



If, in the face of these discouraging and apparently unsurmount- 

 able difficulties, the author ventures to suggest some possible 

 fundamentals of Precambrian paleogeography, he wishes to state 

 beforehand that he feels he is treading on uncertain ground and 



1 Schuchert (1910, p. 517) states this fact concisely when he says: " From 

 the beginning of the Paleozoic, paleogeography can be made out with certainty, 

 but back of that period all is shrouded in obscurity, owing to the absence of 

 a paleontologic record." 



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