148 J. B. Woodworth — Carboniferous Fossils. 



side of the railway track. This section was also measured by 

 Mr. Dodge,* who evidently mistook the dip of the cleavage 

 for that of the stratification planes, in making the beds dip 

 45° JST. No fossils have been found in this section, and, except 

 certain small pitted impressions and fine straight furrows seen 

 in demi-relief on the underside of some red beds, no markings 

 were seen on their surfaces. The calcareous portion of the 

 section differs from the calcareous red shales of the Cambrian 

 in Attleborough and Wrentham in the apparent absence of 

 fossils, a characteristic of the limestone bands in the Carbon- 

 iferous at Attleborough. In part, the carbonate of lime is of 

 vein origin like the lenticular quartz bodies which occur in the 

 same section. 



It has been assumed that these red rocks in the eastern por- 

 tion of the Norfolk County basin are of Carboniferous date. 

 The same presumption has proved only partially true in the 

 southwestern part of the basin between Wrentham and Attle- 

 boro, where a section of red calcareous and sandy strata of 

 lower Cambrian age occupies a narrow belt in the midst of the 

 red Carboniferous. f For this reason, and owing to the ab- 

 sence of fossils in what appears to be the lower portion of the 

 section at Canton Junction, it seems unwise at the present 

 stage of our knowledge to hold on mere lithological evidence 

 all of the red beds in this field to be of Carboniferous age. 



Northward of the last outcrop about half a mile, gray rocks 

 recur on the east of the railroad with nearly vertical dip. 



In addition to the occurrences above mentioned, fossils were 

 also found in the glacial drift at the following localities : 



1. In Canton, about one and a half miles south of the border 

 of the basin : Calamites cistii (?) in a sandstone pebble. 



2. In East Walpole, on the south side of Traphole brook, 

 near the western end of the Neponset swamp, small bowlders 

 carry calamites and plant stems. 



In both these instances, the drift of the fossiliferous pebbles 

 was from the north and from a distance not exceeding three 

 miles, the limit of known Carboniferous in that direction. 



The occurrence of, at least, three dikes in the Canton junc- 

 tion section is interesting as setting aside the sharp distinction 

 which has been thought to exist between the Norfolk County 

 basin and that of Boston north of the Blue Hills. The 

 scarcity of exposures in the former basin is one of the reasons 

 for the apparent difference in this regard. 



Cambridge, Mass., May 28th, 1894. 



* Op. cit., p. 413 



f N. S. Shaler : On the Geology of the Cambrian district of Bristol County, 

 Mass. Bull. Mus. Comp. Zool., xvi, 1888, pp. 13-41. 



