100 FOX ISLANDS. 



which, however, occasionally app u Camden, above all the othei rocks, and then 



Miiks deeplj and disappears beneath them. This state of things causes b great deal of per- 

 plexity, confusion and disagreement among observers; and it will require the utmost care 

 ami attention on the pan of nil, to reconcile the discrepancies ami differences of opinion 

 on this question. On man] of these subjects, much in yet to be learnt in this country ; 

 and though we are here pushing our researches among the newer rocks with great zeal, 

 much remains to be done among the older, ami id ho learnt in relation to the origin of 

 rocks and parent beds. 



§ 2. Fox ISLANDS. 



The islands called For islands, lie ofl" from Camden twelve miles. The] form low 

 ridges, or high reefs or outliers from the main land, and arc particularly well located as 

 fishing stations. 



The formation of these islands is very similar to that of the main land. The principal 

 difference consists in the greater proportion of metamorphism exhibited in the islands. The 

 slams are particularly altered. The cause appears upon the spot ; few places furnishing 

 siirli a number of d\kes as are found on BOine portions of the coast. The effect exhibits 

 If in a hardening of the strata and a crowding together of the iii^ms, and in the de- 

 velopment of many hard oval nodule8, and in man] instancrs imperfect crystals of felspar. 



Those Blates which are unchanged are thin heneath and usually dark colored, and very 

 often charged with sulphur, which imparls to them that peculiar character that has given 

 them the name (if plumbaginous slab . When only a slight change has taken place, there 

 ■ ■ssy Burface, a son of resinous lustre. 



The dykes are the ordinan greenstone, though coarse, yei nothing peculiar; but they 

 contain many nodulesof smooth quart2 much like water pebbles, solid throughout, or with 

 merely a slight cavity in the centre. These break open readily, and some become loose b] 

 atmospheric action. The islands, however, are composed of the magnesian slate and trap 

 dykes, twenty live or thirn feet wide, low Inch must be attributed the strange metamor- 

 phosis the rocks have Buffered both in texture and mechanical arrangement. 



We are unable, in consequence of the concealment of the rocks in this direction, to 

 - mate the width of the Taconic Bystem: they dip N. 65 W. The system ranges up 

 the Penobscot into the interior of Maine ; but in consequence of the proximity of igneous 

 rocks, and the changes which the] have undergone, as well as their resemblance when 

 thus changed to the primal] schists, it ma] snll be difficult to mark out the distinct belt of 

 country over which it prevails. 



Having completed my examinations at Camden, I proceeded to Thomaston, where for 

 a long time beds of limestone have been wrought for marble, but more extensively used 

 and burnt for quicklime. I bad the same intention as when visiting the Rhode-Island 

 quarries of limestone, namely, the determination of the age and relations of the rock. 

 Thomaston is abon i seven miles southeast of Camden, and lies in the direction of the range 



