A CONTRIBUTION TO THE GEOLOGY OF SOUTHERN MAINE 537 



composition. Of the various types selected by us for analysis 

 and for microscopic study no one is identical with his, yet our 

 types from the same rock mass differ from another in as essential 

 respects as do most of them from his rock. The Boothbay rock 

 is invariably porphyritic, the phenocysts being feldspathic, the 

 ground-mass micaceous. On analysis, the ground-mass only 1 

 corresponds to Mr. Bastin's analysis and falls into the subrang 

 prowersose. The whole rock of each of our types is more salic, 

 and the various types respectively fall into the subrangs mon- 

 zonose, umptekose and the unnamed subrang (II. 5. 3. 2.) of 

 which the only analysis given in Washington's tables is that of the 

 augite-minette from the Plauensche Grund of Dresden. Since 

 the Maine rock is of notable extent, and the analysis accurate 

 and from fresh material, it appears justifiable that a name from 

 this locality be given to this subrang of the new system, and 

 the name lincolnose is here proposed for it from Lincoln County, 

 Maine. 



The Boothbay rock (including umptekose, monzonose and 

 lincolnose) is found in two parallel bands about two miles apart. 

 The eastern band outcrops on Squirrel Island (see map, Fig. 2) 

 and again on Spruce Point. In both localities it has been much 

 cut up by later intrusives. Its strike varies from due N.-S. to 

 N. 1 5 E. and it may be found at intervals throughout the 

 length of the quadrangle. It forms Mt. Pisgah and there has a 

 width of about a quarter of a mile. This band was traced in the 

 direction of its strike for twelve miles, the width being very 

 variable. It is often concealed by vegetation and sometimes 

 appears to pinch out altogether. The indications point towards 

 a string of lens-shaped masses barely connected with each other 

 and arranged in a uniform direction. The western band is 

 shorter and wider being apparently three miles in length and one 

 in maximum width. Its widest part is found on the south shore 

 of Campbell pond; from there it extends southward rapidly 

 narrowing to the coast. Mr. Bastin's exposures are about forty 

 miles distant in a N. 20 E. direction. 



Wherever exposed on the Boothbay quadrangle both bands 

 show a marked difference between core and edges. The core 



1 See Analysis II, Table VII. 



