Hitchcock.] 192 [November3, 



Ferrisburg valley ; then after rising a few hundred feet, there is an 

 undulating plateau through the east part of Ferrisburg and Monkton, 

 consisting chiefly of the sandstone disposed in gentle folds. Between 

 the last of the unmistakeable Potsdam rock and the quartz of Starks- 

 boro' is a development of the Calciferous sandrock. It would seem as 

 if the quartz range is separated from the Calciferous by a fault. 

 Next, east of this great quartz or Potsdam mountain, is a valley 

 showing the Calciferous again, followed by the Potsdam quartz abut- 

 ting against the Green Mountain schists, or with an overturn dip 

 beneath them. The structure along this line is very plain, and con- 

 sists of a series of folds. 



Now we can follow these rocks southerly, and with their relative 

 positions established in the north, can understand what the succes- 

 sive variations are. First we will examine the order in the next tier 

 of towns south of Monkton. There is the anticlinal of Chazy, etc., 

 with the fault west of Buck Mountain, in Waltham, bringing up the 

 red Potsdam. This is overlaid by the Calciferous, Chazy and Tren- 

 ton, with their natural easterly dips in New Haven, followed by the 

 same formations in reverse order, with usually high overturn easterly 

 dips and the Potsdam also. Continuing easterly, there are two more 

 folds in the Potsdam covered by limestone, and then a broad band of 

 Calciferous before reaching the high Bristol range of Potsdam quartz. 

 This latter rock sinks down again, holding the Calciferous just as in 

 Starksboro. The Potsdam quartz stands vertically against greenish 

 schists in the town of Lincoln, which may possibly be of about the 

 same age. 



The following is the order, about twenty miles southerly of the 

 last section, from Larrabee's Point in Shoreham to Goshen. Chazy. 

 Trenton and Utica, occur in their natural order separated by a small 

 fault from a Calciferous synclinal uplift. Then the Potsdam, proba- 

 bly the Buck Mountain range, follows on the east, overlaid by the 

 Calciferous, Chazy and Trenton, reaching into Whiting. Probably 

 the slate here overlies the Trenton. East of it the Chazy and Cal- 

 ciferous appear more than once, with high overturn easterly dips. 

 The latter band is immediately adjacent to the Potsdam quartz. 

 This latter range has certainly two anticlinal folds in it, covered by 

 ranges of Calciferous. But on this section almost every dip is east- 

 erly, while the rocks can be traced directly to the north, where the 

 westerly dips are as common as the easterly. The conclusion seems 

 plain, that a greater pressure has inverted most of the folds, and 



