384 THE JOURNAL OF GEOLOGY. 



sents another interesting problem, which is not free from diffi- 

 culties. From its source in Massachusetts it flows southeast 

 across the crystallines to the village from which it takes its. 

 name, where it turns abruptly north along the Triassic sandstones- 

 for ten or twelve miles, when with another wide sweep it crosses- 

 the trap ridges at Tariffville by a deep gorge, and resumes its 

 southeasterly course to the Connecticut. Of this latter part I 

 will speak later, but now arise the questions, "what has been 

 the history of this river," and "why does it turn north at Farm- 

 ington?" 



The Farmington m the Tertiary cycle. A course more accordant 

 with the structure would seem to be south along the Quinnipiac 

 and Mill river valleys to the sound at New Haven. As has been, 

 said before (page 376), Prof. Dana has expressed the opinion 

 that the gorge at Tariffville was occupied by the Farmington irt 

 Tertiary times, and that the Westfield river gap further north 

 and the gorge of the Quinnipiac southwest of Meriden are also of 

 earlier date than the glacial epoch. One reason has also been given, 

 why I differ from him in regard to the Quinnipiac and Tariffville 

 gorges — they are narrower and steeper than those made in sim- 

 ilar rocks during the Tertiary cycle. But more than this, the 

 constructional topography, resulting from the tilting and faulting 

 of the region, could not, it would seem, have caused the Farm- 

 ington to take its present course. Even if it had taken this 

 roundabout course during the baseleveling of the country, it 

 must, since it would have had to cross three trap sheets,, 

 have been captured and led to the sea by the shorter and 

 easier way along the sandstone area. The fact that the Connec- 

 ticut probably persisted in its consequent course is no argu- 

 ment for similar conditions for the Farmington, because the 

 latter is much the smaller stream, and so more easily captured. 

 Nor could the river have been forced into this course during or 

 after the post- Cretaceous uplift, for the land was then raised 

 more at the north than at the south, and any changes from this 

 cause would have been to confirm the river in its southward 

 course. It is very probable, therefore, that in at least the latter 



