Geological Notices. 95 



of Day's meeting-house in Killingly. The stone is used, to a consid- 

 erable extent as a flagging stone, and nothing but its distance from a 

 water communication, prevents a much more extensive use of it, for 

 this purpose. It splits out in layers from an inch to a foot in thick- 

 ness, and of almost any size that may be desired. It is very rare, 

 that slabs containing one hundred square feet, do not exhibit to the 

 eye, a perfectly plane surface. It dips about 15° to the north of west, 

 and crops out wherever it is visible in place on the east side of the 

 hills. The stratum, as seen at the quarries, has a thickness of at 

 least three hundred feet, and probably much more. I was not able 

 to find its junction with other rocks, which is concealed by diluvion. 

 There are occasional thin partings of mica slate, in the stratum. 

 About four miles from the quarries, this feldspar rock passes into well 

 characterized kaolin. Some of the specimens shew the progressive 

 changes from feldspar rock (petuntze), to porcelain clay. At this lo- 

 cality, however, the clay does not seem to exist in sufficient quantity, 

 to make it worthy of an exploration ; but there are probably other 

 beds in the range, that may perhaps be rendered available. 



The granular quartz rock, with fibrous arragonite, is the stratum to 

 the east of the latter. My attention was first drawn to it, by seeing 

 it used in the towns around for hearth and jamb stones. It has not 

 been regularly quarried, until within a {ew years. I am not positive 

 that this constitutes more than a mere bed, as I did not trace it for 

 more than half a mile. The dip and line of bearing of this stratum, 

 as well as all to the west of it, for thirteen or fourteen miles, are about 

 from 10° to 15° degrees to the w. n. w. for the former, and n. n. e. 

 and s. s. w. for the latter. 



The gneiss in thick strata, may perhaps with more propriety be 

 called granite, as the same stratum a {Gvi miles north, (at Atkins's 

 meeting-house in Killingly,) passes into well characterized granite. 



A ridge of contorted gneiss, extends some miles north and south 

 of the line of section, between Killingly and Brooklyn, and it contin- 

 ues to shevp itself in place occasionally, so as to present a breadth of 

 about two miles. The cliffs shew it on the large scale, but small 

 masses not unfrequently shew it in a remarkably distinct manner. 

 The zigzag and curve Hnes, pass in every direction, and the idea 

 naturally occurs, that when in a soft state, the masses had been for- 

 ced against, and bent and penetrated each other, in every direction. 



Between this and the preceding stratum, much of the gneiss is por- 

 pbyritic. In Brooklyn, the gneiss sometimes almost passes into horn- 



