bee:n^ardston series of upper devoxiax. 297 



and felds^iar, very rusty and carrying pyrite and galena, and rarely nuisco- 

 vite in broad scales. Going 33 feet along the strike, one finds the rock 

 changing to a massive, dark leek-green hornstone, which continues ii long 

 distance, becomes in places black, and assumes a small columnar structure, 

 and at last returns to the coarse mixture of quartz, flesh-colored orthoclase, 

 and muscovite, the latter often in plates about an inch across — the whole 

 coarsely but distinctly bedded in laminae 1 to 2 inches thick. 



This is succeeded in ascending order by a well-developed, coarse 

 muscovite-scliist 13 feet thick, which dips beneath a Iwd of \ery siliceous 

 limestone about 40 feet thick, very rusty externally, in the interior white 

 to flesh-colored at base, but soon becoming dark-green to black above, and 

 very hornblendic. In places it is a pure amphibolite, but it is generally 

 mottled with white calcite. It is cut by two dikes, 3 to 7 feet thick, of 

 coarse granite. Then begins a great bed which seems to rest ujjon the 

 hornblende-calcite rock, but the exposure leaves this indistinct. This lied 

 begins at base as a greenish, apparently calciferous (juartzite (it rusts 

 deeply), and makes the mass which projects into the Connecticut at a point 

 just north of the mouth of Millers River. At base some parts are conglom- 

 eratic, quartz pebbles one-half to 1 inch long occurring. This rusty layer 

 is about 20 feet thick. Then a thin layer of amphibolite, like the other, 

 caps the quartzite for a short distance (72 feet) along- the water's edge, and 

 the latter rock, the quartzite, runs on in great undulations fm- 65G feet 

 toward Millers River, its average strike agTeeing closely with the course of 

 the Connecticut at that point (S. 60° W.) and its dip being 42° W. The 

 high, bare cliffs give almost unbroken exposures between the two exposures 

 of the fault at the extremities of the section, and leave the stratigraphy 

 inicertain at only one point. The upper quartzite is thin-fissile in its upper 

 layers, bluish at times, and repeating all the flinty varieties seen at "The 

 French King" (16 feet). At the great point just north of the mouth of 

 Millers River, where the shore-line swings round to the east as one passes 

 up the bank of the latter stream, this grades below into a perfect feldspathic 

 gneiss of medium grain, with a little greenish mica (20 feet), which passes 

 below into coarse granitic gneiss or a gneiss breaking in laminte nearly an 

 inch thick but composed of the coarse orthoclase and large muscovite 

 scales of a common coarse granite. The musco\'ite scales are often an 

 inch broad, and are generally in the plane of foliation (30 feet). 



