GONANIOUT ISLAND. 229 



lying the sandstone and conglomerates along the entire northern margin of 

 the hill is a series of black shales, at times very coaly. Intercalated with 

 the shales were narrow bands of sandstone, indicating a low eastward dip, 

 sometimes as low as 20°. This eastward dip is significant in connection 

 with the question of the comparative geological age of the green shale 

 lying immediately to the east. 



NORTHERN HALF OF THE ISLAND, NORTH OF ROUND SWAMP. 



The first exposure of rock on the western shore occurs just south of a 

 very small sand beach, where the coast line of the island begins to take 

 a direct northern course. Here occurs sandstone with some thin conglom- 

 erate layers showing a strike of N. 5° E. and an eastward dip. North of 

 the beach there is a stretch of coaly shale, with an eastward dip.' Then 

 follows northward a series of sandstones with interbedded conglomerate 

 layers, as far as a small stream entering the bay near the north end of 

 Slocums Ledge. Northward coaly shale is again exposed, showing- a strike 

 of N. 8° E. and an eastward dip. Yet north of this is a long sandstone 

 exposure with a strike of N. 13° E. and an eastward dip. Still farther north 

 occur coaly shales again, as far as Fowler Rock, near the middle of Great 

 Ledge. The line of shore exposures above mentioned, which might be 

 called the ledge expostires on account of their proximity to Slocums and 

 Great ledges, show the greatest degree of metamorphism among the rocks 

 of the island. From Fowler Rock to a short distance northeast of Sand 

 Point there are no shore exposures. 



Northeast of Sand Point the shore lies on coaly shales interstratified 

 with sandstones. The strike is N. 3° E.; the dip is also east. Northward 

 there are sandstones with minor conglomerate layers, having the same strike. 

 Farther north is more coaly shale, with intercalated sandstones, with the 

 same strike of N. 3° E., and this is also shown by the most northern 

 exposures on the western side of the island, coaly shales being- exposed just 

 west of North Point. 



Exposures begin again about 1,200 feet east of North Point along the 

 north shore and continue for several hundred feet. The rocks are chiefly 

 shales, much squeezed in a direction from east to west, making a strike of 

 N. 18° E. and an uncertain dip, which is believed, however, to be eastward. 

 The next exposures along the eastern shore, going south, are almost directly 



