64 BULLETIN OF THE 



the surrounding sandstone, whose strike and dip still conform to the 

 monocline of the region. Further extension of the cross-section to the 

 east is not necessary for the present, and the return to Meriden may be 

 made by the road that passes around the southern end of Lamentation 

 Mountain, there known as Chauncy Peak. 



A general section across the strike of the monocline is placed in its 

 proper position oil Fig. 2. A vertical section, constructed on the mar- 

 gin of Fig. 2 from the material gathered on this excursion, contains 

 about fifteen hundred feet of sandstones and conglomerates at the base, 

 then two hundred feet of amygdaloidal trap in the anterior ridge, fol- 

 lowed by six hundred feet of thin bedded sandstones and shales in the 

 anterior valley, four hundred feet of heavy trap in Lamentation Moun- 

 tain, and fifteen hundred feet of sandy shales before coming to the pos- 

 terior ridge, which may be one hundred and twenty feet thick. The 

 total thickness of the aqueous and igneous beds traversed is some five 

 thousand feet. It is at present still uncertain from all that I can learn 

 how many feet of deposits are below the base of this section before 

 reaching the crystalline foundation on which the Triassic formation 

 rests ; and the thickness of the beds that originally overlay the poste- 

 rior trap is equally indefinite. 



Excursion 2. — Cross-Section of Shuttle Meadow. 



In order to measure the thickness of the underlying beds or to deter- 

 mine their sequence, a second excursion may be made to some point far- 

 ther west, — as by rail from Meriden to New Britain, and then on foot 

 or wheels to Shuttle Meadow reservoir, three miles to the southwest. 

 From the valley south of the reservoir, the ground rising to the east 

 leads over several outcrops of brown and red sandy shales (1, Fig. 3), 

 with strike N. 30° E., and dip 10° eastward, before reaching the bold 

 western face of the High Rock trap ridge (2). If one should climb 

 over this rugged ridge and descend across the meadow at its eastern 

 foot, a small trap ridge would be found (11), trending parallel to the 

 main ridge, but much concealed by drift. No shale or sandstone is seen 

 accompanying it, and so small an observation is hardly worth the time 

 it will cost. Returning now westward to the valley south of the reser- 

 voir and ascending its western slope, the enclosing ridge is found to con- 

 sist of amygdaloidal trap (3), with a bold cliff, trending N. 10° E., and 

 facing westward over the Southington valley-plain. A mile to the south, 

 a bed of impure limestone is exposed in a quarry on the back of the trap. 



