796 THE JOURNAL OF GEOLOGY. 



region. The fault probably extends a considerable distance 

 farther to the southward but its course has not yet been traced. 

 The northern course of the fault is indicated on the map. 



Starting at the Maltby Quarry, where the surface rock on 

 both sides of the fault line is Canaan Dolomite, and going north- 

 ward, to the west of the fault line the generally northerly pitch 

 carries the beds lower and lower so that Egremont Limestone is 

 met before Sheffield is reached. On the east, however, no such 

 pitch exists, and Canaan Dolomite is the surface rock for the 

 entire distance. The Riga Schist has not been found in actual 

 outcrop abutting against the fault plane and separating the two 

 calcareous horizons, but this is explained by the absence of out- 

 crops along the river valley. The map and section in Fig. 5 are 

 introduced to indicate how the Riga Schist is believed to meet 

 the dolomite at the fault line. This map is drawn on the same 

 scale and has the same legend as Plate V. An examination of 

 Plate V. will show how the hard Riga Schist of Miles Hill has 

 caused a deflection of the Housatonic River to the eastward in 

 that vicinity. The important easterly deflection which exists in 

 the vicinity of the Canaan Camp Ground (cf. Fig. 5) is believed 

 to be caused in the same way. The low area between the river 

 and the road to the west of this bend is bare of outcrops, but 

 Riga Schist is encountered on the road and covers a considerable 

 area west of it. On the east of the river at this bend the tremo- 

 litic Canaan Limestone is encountered almost at the river's bank. 

 There seems, therefore, reason for believing that in this vicinity 

 the fault follows the river and that the two rocks abut against 

 one another at the fault plane. 



To the southward of the Maltby Quarry the fault is of a 

 somewhat exceptional character, since the prevailing northerly 

 pitch of the beds to the west of the fault line brings beds lower 

 than the dolomite (First Cambrian Ouartzite and then Cambrian 

 Gneiss) to the surface in the Cobble. The upper limb of the 

 fold is no longer the overthrown limb, but it is forced to a lower 

 position. We have here, then, an example of a fault, which at 

 the north is a rather steep overthrust with Canaan Dolomite over 



