298 GEOLOGY OF OLD HAMPSHIRE COUNTY, MASS. 



This stratum is followed below, just at tlie junction of the rivers, by 

 a heavy bed of a very coarse, very micaceous muscovite- schist. This 

 mica-schist incloses a great number of lenses of coarse granite, its laminae 

 separating to inclose them, and the strike of the rocks continues closely 

 parallel to the course of the Connecticut. This stratum passes beneath 

 the water at the place of junction of the two rivers, and the granite 

 lenses rise in twelve small islands which stretch across the mouth of 

 Millers River (105 feet). 



The mica-schist changes suddenly below into a dark, much-jointed and 

 yet fissile biotite-gneiss. The biotite is bronze-colored, but green superfi- 

 cially. This is followed finally by the basal quartzite, containing- at first 

 bands of coarsely feldspathic quartzite with scattered red garnets like those 

 common in granite, and broad flakes of muscovite, and with quite large gran- 

 ite lenses. Below it is for the most part a green to flesh-colored, compact 

 quartzite with feldspathic and biotitic layers, and resembling closely that 

 at the north end of the exposure at "The French King," and faulted, as 

 already detailed, against the older gneiss just below the bridge over Millers 

 River. (See fig. 21, p. 295.) 



The order from the fault upward is, thus, at both ends: (1) quartzite, 

 (2) mica-schist, (3) amphibolite and limestone; and it is doubtful whether 

 the order contmues upward, (4) rusty quartzite, (5) amphibolite, or 

 whether the two upper are repetitions of the lower members of the series. 



Crossing Millers River, the fault line runs through the high Mine Hill 

 west of the village of Millers Falls, and, especially the band of schist and 

 gneiss impregnated with granitic material, makes the crest of the hill. This 

 band is greatly brecciated and its fissures are filled with magnetite, which 

 has suggested the name, while on the western slope a greenish compact 

 quartzite or hornstone caps the feldspathic beds. 



Southward across the Montague plain all the outcrops are to the east 

 of the line of junction of the two formations, and thus lie in the older gneiss, 

 until, on the southern border of the great sand plain and just northeast of 

 the village of Montague, there occurs a great mass of the same gray to 

 pale-green, greatly-jointed and brecciated quartzite, quite massive and 

 hornstone-like in texture. A few rods to the east, across the railroad, the 

 older gneiss rises above the sands, dipping beneath the quartzite. South 

 and west everything is covered by the Triassic sandstones, but on the north 



