138 Thirty-second Report on the State Museum. 



probably the entire southwestern corner of the township — that is to say, an area 

 commencing at the southwest corner near or at Fletcherville east to the line of 

 Mullen brook, thence northward to the north of Nichols' pond and west to the 

 township line. The old workings of Campbell Hill are located in the vicinity 

 of this pond on lots 168 and 166. With the exception of this area and probably 

 a small area south of Mullen brook, Westport is occupied by the Labradorite 

 series, except that portion covered by the Cambrian limestones along the lake. 



The entire eastern two-thirds of the " Iron Ore Tract " has been carefully 

 studied, and nowhere are other rocks to be found than those belonging to the 

 Labradorite series. The general pitch of these rocks, here forming the lake 

 range, is to the northward as far as the northern boundary of the tract or a line 

 east and west through the village of Westport.- 



The general structure of the northern half of the township is not settled, but 

 we know that along the northern shore of the Westport bay we have the same 

 Upper Laurentian series pitching to the southward. A great deal of the northern 

 portion of this township is concealed by glacial debris and Champlain clays. 

 Split Rock mountain occupies the northwestern portion of this township, and 

 extends northwestward into the township of Essex. Titaniferous iron ore has 

 been mined on this mountain. Along the lake shore, from the village of West- 

 port to the Moriah township line, the Cambrian limestones occur everwhere. 

 They are also exposed in place not far from the eastern boundary of the Iron 

 Ore Tract, near and at the base of the lake range. 



The region between the Iron Ore Tract and the lake is covered by the blue 

 Champlain clay, which has been deposited principally on the limestones, but 

 occasionally extending into bays and resting on the gneisses. At the village of 

 Westport, the Potsdam sandstone makes its appearance in the bed of the brook. 

 There are beautiful exhibitions of glacial action and glacial moraines in many 

 parts of this township. 



ESSEX, WILLSBOROUCH, LEWIS AND CHESTERFIELD. 



These townships I have not been able to study, except in a very superficial 

 manner. They are, however, occupied principally by the Upper Laurentian 

 series as far as my observations carry me. 



In the southwest corner of Chesterfield township, there is an outcrop of Titan- 

 iferous iron ore, and also large deposits of crystalline limestone containing much 

 plumbago. Along the lake shore the Cambrian limestones occur in many 

 places, capped by the Champlain clays and, sands. At Keeseville, the Ausable 

 river cuts through the Potsdam sandstone in a deep gorge or chasm, celebrated 

 for its picturesque scenery. 



CROWN POINT. 



Lower Laurentian. 



The area occupied by this group is comparatively small. It is situated in the 

 western part of the township, bounded on the north and west by a stream flow- 

 ing into Paradox lake ; its southern and eastern boundary I have not as yet 

 determined. Hammondville is probably located about the center of the area. 

 There are large deposits of magnetic iron ore developed at this point. 



The geological structure is exceedingly complicated. The probability is that 

 it is an uplift cut off on the north and west by a fault, with an eastward pitch 

 complicated by minor folds, faults and contortions. Crystalline limestone flanks 

 it on the north and west. To the east it is followed by a series very similar, 

 and probably identical, with that associated with the limestones of Moriah 

 township. 



