374 DALE— CAMBRIAN MANGANESE DEPOSITS OF [April 25, 



been made by Mr. A. F. Buddington, who is studying the pre-Cani- 

 brian rocks of this region. A brief description of these formations 

 at this time will be necessary for a comprehensive view of the New- 

 foundland manganese deposits. 



Laiirentian: The rocks of this formation are in great part gneissic 

 and granitoid, and are probably the oldest rocks of the area. 



Huronian: This formation, which is equivalent to the " Concep- 

 tion " of Dr. Walcott, consists principally of the Conception slates 

 which are of tufaceous marine origin. They are intruded by bosses 

 and dikes of granite, diorite, monzonite, and gabbro, and contain 

 basaltic and rhyolite flows. The Conception formation was esti- 

 mated by Murray and Howley to have a thickness of 2,950 feet. 



Torbay: This formation consists of about 3,300 feet of green and 

 purple slates and argillites. 



Momahle: An estimated thickness of 2,000 feet of brown and 

 black sandy shales overlies the previous formation. 



Signal Hill: Red and green sandstones, conglomerates, shales, and 

 arkoses largely of continental origin comprise this formation, the 

 thickness of which is about 9,000 feet according to an unpublished 

 estimate by Mr. A. F. Buddington. 



Random: About 1,000 feet of green and red sandstones and 

 white quartzites with occasional basalt flows comprise this series. 



Murray and Howley in their report of 1868 for the Geological 

 Survey of Newfoundland describe the general structural features of 

 the Avalon Peninsula as follows : 



" The region in question, in particular, and probably the whole island in 

 general, seems to be arranged in an alternation of anticlinal and synclinal 

 lines, independent of innumerable minor folds, which preserve throughout a 

 remarkable degree of parallelism, pointing generally about N-NE and S-SW 

 from the true meridian, corresponding with the strongly marked indentations 

 of the coast as well as the topographical features of the interior. One such 

 great anticlinal form occurs within the region examined this year, with a cor- 

 responding synclinal; the axis of the former was found to be more or less 

 overlaid unconformably by rocks containing fossils of Lower Silurian age, 

 none of which were of less remote antiquity than such as are attributed to 

 the horizon of the upper Potsdam group." 



" The axis of this anticlinal runs in a moderately straight line from Cape 

 Pine on the south coast to that part of the Peninsula and coming up from 

 below the Intermediate Series, occupies more or less of the surface from 

 the vicinity of the Renew's Butterpots to the shores of Conception Bay be- 



