Cttshing — Geology Of Clinton County. 



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5. Sandy, laminated clay, somewhat undulating, . . feet 9 inches. 



6. Laminated, clayey sand, much folded and contorted, 1 foot. 



7. Alternating thin bands of sand and clay with occasional rounded 

 boulders, to the base of the section, with a six-inch clay seam in its upper 

 part, which unites with the upper jointed clay, No. 4, at the w est cud of the 

 section, but one hundred feet away is three feet below it. At the east end 

 everything is cut off by the sudden downward dip of the upper yellow- sand. 

 The white sand, No. 3, contains thin streaks of fine gravel and occasional 

 small clay nodules, and becomes very gravelly at the east end of the cut. 

 The whole seems clearly a shore deposit in standing water. 



Ausable. 



This is the smallest of the townships, and lies in the southeast, with the 

 Ausable river forming its southern boundary except at the extreme east, 

 where a narrow strip of low sandy land belonging to the modern delta of the 

 liver is included in the county. 



Series I. The gneisses cross the river into the county at Clinton ville 

 and continue thence northeastward about half-way across the township, w hen 

 they are overlapped and indented by the Potsdam, their line of outcrop 

 swerving to the west and then to the northwest. The wide gneissic hill in 

 the western part of the township is known as Arnold hill, and is 

 topographically an extension of Palmer hill in Black Brook. The Little 

 Ausable river cuts through it in a narrow, steep-sided valley, apparently due 

 to a fault, with the- gneiss showing grandly on the east side. At Clintonville 

 and northeastward from it, are also excellent exposures. Then follows a drift 

 filled depression a mile in width, beyond which the gneiss again crops out in 

 two low hills, round which the gabbro sweeps in a semi-circle. 



The exposures are, for the most part, of ordinary microperthitic gneiss, 

 with some plagioclase gneiss toward the north, and with the usual bands of 

 hornblende gneiss. On Arnold hill are important ore-bodies. About one 

 mile southwest of Iiarkness station and near the railroad, is a strip of no great 

 width which resembles a dike and is probably a sheared strip. It is a finely 

 granular black rock, made up of plagioclase, orthoclase, hornblende, biotite 

 and magnetite, hence with the mineralogy of the hornblende gneisses. 



Series III. Lying east of the gneisses, and forming the rather Low 

 elevation known as Halleck's hill, is an area of anorthosite. It has a breadth 

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