339 



rian group, in accordance with the inferences drawn by De 

 Beaumont from its orographic positions. 



Dr. Jackson then explained how he and other Geologists had 

 been in the habit of explaining the anomalous facts' concerning 

 the position of these rocks, under the idea that they might be the 

 new red Sandstone deposited on any rock that happened to be 

 uppermost at the epoch of that formation. It is certainly a very 

 curious fact, that the coal measures of Mansfield, Mass., and of 

 Rhode Island are also deposited in a so called primary trough, 

 or in a trough of Granite gneiss and mica slate rocks without 

 any carboniferous limestones and without any cappings of new 

 red Sandstone strata. While on the Connecticut River the 

 Sandstones which have been supposed to be equivalent to the 

 new Red are also deposited in a similar trough and contain no 

 coal rocks beneath them. These facts need much and prolonged 

 research for their full explanation, and we have not yet obtained 

 all the data that are needed for a full and rational discussion of 

 the subject. 



Mr. Wells read a paper, in connection with this subject, 

 in which his object was to show that the reference of all 

 the stratified and fossiliferous rocks of the Connecticut 

 Valley to one formation has been made upon insufficient 

 data, and that it is doubtful whether the upper members of 

 these Sandstones belong to the new red Sandstone or to 

 the Oolitic period. 



It is difficult to determine the age of these rocks, since, owing 

 to the absence of all underlying carboniferous or older sediment- 

 ary rocks on the one hand, or of any superimposed fossiliferous 

 formations on the other, Geologists have been compelled to rest 

 entirely upon their lithological characters and the doubtful 

 evidence of fossils contained in them. He thinks that they con- 

 sist of two distinct formations, differing widely from each other. 

 In the lower beds we find rocks only which exhibit the charac- 

 teristics generally attributed to the new red Sandstone ; of a 

 color ranging from a light to a brownish red, and differing 

 greatly as regards fineness. The rocks lying above these, 

 which he would refer to a different formation, consist of red. 



