Hobbs — Southwestern New England Region. 437 



Art. XL1IL — The Geological Structure of the Southwestern 

 New England Region ; by William Herbert Hobbs. 



Former Assumption of Deformation largely by Folding. 



The southwestern New England region, by reason of its 

 prominence in the early heated discussions upon the strati- 

 graphic and dynamic problems of geology, has sometimes been 

 designated " The Battlefield of American Geology." Its 

 prominence in this controversy is to be explained chiefly on 

 two grounds — its proximity to the early American colleges and 

 the exceptional intricacy of the problems involved in its study. 

 The first condition is responsible for the large number of geolo- 

 gists who figured in the Taconic Controversy ; the second for 

 the wide range of opinions expressed, for where little can be 

 learned by observation much may be assumed, though not 

 without challenge. It is certainly most unfortunate that the 

 solution of the most fundamental problems of the science, in 

 their application to America, should have been sought in a 

 region which probably ranks with any yet known both in the 

 intricacy and in the obscurity of its geological structure. 



All work earlier than that of Dana may be to-day passed 

 over as offering nothing of value upon the geological structure 

 of the region. Charles Hitchcock and Ebenezer Emmons in 

 Massachusetts did, indeed, prepare some careful sections 

 across the western mountain ranges, and these sections fail to 

 be of service to-day not from any lack of ability or of thorough- 

 ness on the part of the excellent observers, but because any 

 work so limited and carried out upon ideas of rock structure 

 which were current at the time is wholly inadequate. Per- 

 cival's work in Connecticut was essentially areal mapping, and 

 while his observations of petrographic characters and his corre- 

 lation of exposures to form rock belts must challenge our 

 admiration, he was yet too wise and too cautious to risk any 

 dogmatic statements regarding the tectonic structure of the 

 region. It is clear, however, that he believed the crystalline 

 rocks to be given their present attitudes as the result of system 

 of flexures.* 



Dana by most careful work, chiefly areal, but in part struc- 

 tural also, extending throughout the area from Yermont to 

 Long Island Sound in New England and in much of eastern 

 New York, was able to solve many of the problems which had 

 vexed the early school of geologists, even though he was too 

 * Percival, Geol. of Connecticut, New Haven, 1842, pp. 289-298. 



