Page:The Journal of geology (IA journalofgeology11893univ).pdf/399
extended twenty-five miles or more farther inland. If, in the time which has elapsed since the deposition of these beds, there has been erosion sufficient to strip them off from such a broad area in New Jersey, may they not, in Connecticut, under presumably similar conditions, have been equally eroded?
There is much which makes this hypothesis attractive, and, as the facts were first studied, it seemed the most likely one. It affords a good explanation, not only for the courses of the Housatonic and Connecticut, but also for other rivers along the sound. It seems, also, at first thought, to be well supported by analogy from New Jersey. But a closer study of the situation in that state reveals marked differences in the attendant circumstances. There the soft Triassic sandstone must have been worn down to a lowland early in the Cretaceous cycle, perhaps by the close of Jurassic time or thereabouts, while the harder crystallines retained a strong relief. The slight subsidence, which marked the beginning of marine Cretaceous in New Jersey, allowed the Cretaceous sea to transgress rapidly the baseleveled sandstones to the foot of the crystalline hills, but not to cover them to any extent. It is not probable that the crystallines in Connecticut had been brought nearer to baselevel than those in New Jersey at the time of the Cretaceous deposits. There is no evidence to show that the subsidence was greater in Connecticut than in New Jersey, and, therefore, from a priori considerations, the conclusion would seem to follow that the subsidence, which permitted the Cretaceous sea to cover the Triassic sandstone area of New Jersey, was not sufficient to permit the sea to cover the then unsubdued crystalline hills of Connecticut. Although this hypothesis is not to be hastily thrown aside, for theoretical reasons, yet it would seem necessary to hold it very lightly, at least until some positive proof is found of the former existence of the Cretaceous or some later formation in that region. The first suggestion, that the lower Connecticut was a consequent river in the Cretaceous cycle and was revived by the post-Cretaceous uplift, is, at the present state of knowledge, the most probable.
The Farmington. The roundabout course of this river pre-