207 



and Hockley Lane. Topographically it is essentially one con- 

 tinuous ridge, save where it is crossed by Town Brook and the 

 railroad at West Ilinghanj Station. 



The most continuous ex[)osures ot this narrow helt arc in the 

 vicinity of Ilerscy Street ; and the di]) in this part of the area, 

 especially, is quite constant — S. 70°. The most northerly 

 outcrop along this line is the ledge of conglomerate (13)^ ahout 

 150 feet west of Hersey Street, in the rear of the second and 

 third houses from the corner, on South Street. A few yards 

 south of this ledge, in the rear end of these lots and extending 

 into the adjoining lot on the south, is an outcrop of dark red 

 slate (12). The slate nnist cross Hersey Street at the first 

 hend ; and it is exposed repeatedly along the base of the con- 

 glomerate escarpment from 200 to 300 feet east of the street. 



Going up Hersey Street from the railroad, the first rock 

 actually seen is the conglomerate (11) bordering the red slate 

 just referred to on the south. It commences a hundred feet or 

 so west of the street ; and its northern l)order forms a con- 

 tinuous escarpment from IT) to 20 feet high, due to the erosion 

 of the red slate and extending about 500 feet east of the street. 

 This escarpment is the northern edge of an area from (300 to 1,000 

 feet in length (E.— W.) and 500 feet in breadth, over which 

 the ledges, as the map shows, are almost continuous, and the 

 thickness of the several beds admits of accurate measurement. 

 The conglomerate just described has a breadth of from 75 to 90 

 feet ; and it is followed on the south in succession by about 20 

 feet of red slate (10) ; from 40 to 50 feet of conglomerate (9) ; 

 25 feet of red slate (<S) : from 35 to 45 feet of conglomerate 

 (7) ; from 115 to 135 feet of red and gray slate (6) ; from 

 100 to 130 feet of gray sandstone with some gray slate (5) : 

 and 40 feet of conglomerate (5). 



This Hersey Street section is broken by several large and 

 irregular dikes (see PI. 7) ; but the breadth of the trap is 



1 The numbers in parentheses refer to the general tabh? of Ilinghani strata on page 

 202. 



