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of a volcano does at present. In this way it covered over the chalk of 

 Antrim, and the trap is itself now the surface rock in nine- tenths of 

 the eounty. 



In the county of Antrim, which is nearly all covered over with 

 trap at the surface, and which is sometimes arranged in layers, some- 

 times in lenticular masses, sometimes in large amorphous masses, the 

 layers assume a level position. They appear to be guided in the first 

 instance by the lie of chalk on which they rest, which may be said to 

 be level. 



Fig. 4. 



Alternating Layers of Trap and Ochre, resting on Chalk, at Garron Point. 



Fig. 4, is a diagram of the sectional view at Garron Point on the 

 coast, 35 miles north of Belfast. The dark coloured layers represent 

 solid hard trap ; the lighter layers are of soft red ochre, alternating 

 with the hard beds. Studying the well-exposed section in that place, 

 leads to the conclusion that the whole trappean mass, which forms a 

 precipice of about 500 feet high, as it rests on the white limestone, or 

 indurated chalk there, has been produced from a submarine volcano, 

 in which the ejected matter consisted of melted trap mixed with ashes. 

 The hard beds are formed from the melted rock, thrown up in a vol- 

 canic fissure or funnel, and spread out in the bottom of the sea ; the 

 red soft beds, formed out ot the ashes, disseminated in the water, 

 making a red sea, and deposited in calm water, as a red, soft bed of 

 ochre, each bed of trap representing an eruption. 



