134 Thirty-second Report on the State Museum. 



way of Gill brook to the neighborhood of Nipple Top mountain, where the 

 head-waters of the west branch of the Schroon river have their origin, north of 

 Elk lake or " Mud pond." This west branch of the Schroon river flows south- 

 ward to the neighborhood of the old cord-du-roi road leading from Root's or 

 Schroon River post-office, to Tahawus, where it takes an easterly course. 



From the neighborhood of Clintonville, on the Ausable river, the road leads 

 southward through Lewis to Elizabethtown, along the line of a northeast and 

 southwest valley, which is continuous with the valley of the Boquet river, 

 extending nearly on a line with the above road, from Elizabethtown southward 

 to Euba Mills. 



The course of the valley of the Black river from its confluence with the Boquet 

 to its head-waters at Lincoln pond, is in general that of the Boquet from Eliza- 

 bethtown to Euba Mills, and is in direct line with the valley of the Schroon 

 river and Schroon lake. 



There is also the valley now occupied by Lake G-eorge, entering only in part 

 into this country, which has the same general course as the above valleys. 



There are many other smaller and less important valleys which are similarly 

 arranged. I find that these valleys are along the lines of general upheaval. 

 The valleys are anticlinal and monoclinal escarpments, undoubtedly in some 

 cases accompanied by faults. The structure of the western portion of Essex 

 county, I have not been able to study ; the rocks there, however, belong 

 principally to the Labrador Series. 



The river courses do not necessarily cut down to the Lower Laurentian rocks 

 along the deep valleys, but they do expose them along portions of their courses 

 in many places. In the eastern portion of the county, the Lower Laurentian 

 or Magnetic ore-bearing series forms high ground, though I have not yet proved 

 that it forms the highest mountain ranges east of the Schroon and Boquet rivers. 

 I am at present inclined to think that other measures cap them. The main mass 

 of higher mountains west of these two rivers is formed by the Upper Laurentian 

 or Labradorite series in which the Titanic Iron Ore abounds. These measures 

 extend eastward through the northern half of Elizabethtown, flanking the lower 

 rocks on the east in the township of Westport, forming the lake range the entire 

 length of the township, as well as the lower range of Split Rock mountain. 



The Lower Laurentian occupies a portion of the southwestern edge of the 

 township of Westport. The southeast portion of Elizabethtown, lying south 

 and east of a line drawn from the Kingdom Forges to New Russia and thence 

 to Euba Mills, is occupied by the Lower Laurentian, extending into and occupy- 

 ing the northern half of the township of Moriah. There is a belt of rocks in 

 the southern and southeastern portion of Moriah and northern part of Crown 

 Point, the geological relations of which are not determined, but belong in the 

 group of Lower Laurentian. 



The northwestern portion of Crown Point is occupied by the Lower Lauren- 

 tian, in the midst of which are located the Hammond mines at Hammondville. 



In the northern portion of the township of Moriah are the enormous mines of 

 the Port Henry Iron Ore Co., and Witherbee, Sherman & Co., at Mineville 

 and vicinity. The belt of rocks occupying the southern part of the township of 

 Moriah and eastern portion of Crown Point, extends southward into Ticonderoga, 

 occupying the greater part of this township, and belongs to a subdivision in which 

 the sulphur ores abound. This subdivision is one of the Lower Laurentian, but 

 its relation to the Magnetite series is still doubtful. It is characterized by'light 

 weathering garnetiferous gneisses with their beds of magnetite, containing often 

 a large percentage of sulphur, and thinly bedded quartzites. Some of the 

 crystalline limestones undoubtedly belong in this group, and it may be that 

 they will all be proven to be a portion of this series. 



