528 INCH KENNETH. GEOLOGY. 



extend far to sea around it in almost every direction, and 

 render its navigation difficult, or, to those unacquainted 

 with the coast, even perilous. The rocks are almost 

 entirely of secondary formation, and consist of sandstone 

 and conglomerate. The strata are variable in colour, 

 being lead-blue, white, or red, or variously mottled with 

 all these hues, while even the same stratum, blue in one 

 place, may be red or white in the next. This rock is 

 sometimes mixed with much calcareous matter, at others 

 it is simply quartzose. In general the strata of fine sand- 

 stone are uppermost, but this is by no means an invariable 

 rule, as they will be sometimes found alternating with 

 the conglomerate ; and it even happens, as in other places, 

 that a single portion of any given bed may be found con- 

 sisting of a coarse conglomerate, while the remainder is a 

 fine sandstone. The beds of conglomerate, where most 

 accessible to observation, constitute a mass apparently of 

 about 100 feet in thickness. Their basis consists of a mixture 

 of coarse and fine sand, and the imbedded fragments are 

 either sharp or very little rounded, being formed of small 

 and large pieces chiefly of quartz and quartz rock. 



In most places this rock is the lowest visible one, reach- 

 ing far beneath the spring tide low water mark. But in 

 two or three points on the western side the basis on which 

 it rests can be seen, especially at low water, the period 

 which a geologist should always choose for examinations 

 of this kind. The sandstone and conglomerate are 

 inclined at a low angle, rarely reaching ten degrees, and 

 dip to the N. N. W. The rock on which they rest lies, 

 on the contrary, at an angle of forty or forty-five degrees, 

 and its dip is about S. S. E. The plane of the former set 

 of beds is therefore placed on the edges of the latter, or it 

 lies in the position which has been called unconformable. 

 The lower rock consists apparently of quartz rock of 

 an exceedingly compact texture, and of a purplish and 

 blueish hue. From those two circumstances of position 

 and structure, it must be concluded that these strata 



