492 



PKOF. J. W. SPENCER ON" THE GEOLOGICAL AND [NoV. I9OI, 



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This bank is about 55 miles long 

 and from 18 to 28 miles wide, with 

 an area of 1400 miles. It is only 

 slightly submerged, to a very uni- 

 form depth of about 100 feet. But 

 even from the nearest islands — • 

 Guadeloupe, Montserrat, and Nevis, 

 which are situated on the same great 

 submarine plateau or ridge — this 

 island bank is separated by somewhat 

 broad depressions reaching to a depth 

 of 1800 feet, or in a few places the 

 narrower channels have depths from 

 2000 to 2500 feet. Thus the bank 

 presents a striking physical unit, as 

 of an extensive plain interrupted 

 by low hills, with the remains of 

 mountains occurring on the southern 

 side of what is now the island of 

 Antigua. The margins of the bank 



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are everywhere abrupt and precipi- 

 tous, and they are somewhat in- 

 dented by deep valleys extending to 

 the more profound depressions. 



The island of Antigua has a 

 maximum length (east and west) of 

 16 miles and a breadth of 13, with 

 an area stated at 108 square miles. 

 Bat the coast-line, especially of the 

 eastern half, is very much broken up 

 into lobes by shallow bays. These are 

 occupied by numerous islands, keys, 

 and reefs, among which the extension 

 of the land- valleys can be followed. 



The portion of the island south, or 

 south-west, of a line extending from 

 the hills 2 or 3 miles west of St. 

 John's across the island to Falmouth 

 Harbour, forms a zone characterized 

 by the remains of old mountain- 

 ranges (the highest summit. Boggy 

 Peak, reaching to 1330 feet above 

 the sea), and relatively large deep 

 vallej's. There are few precipitous 

 cliffs, but the declivity of the 

 mountain-sides is steep, and the 

 streams in the deep valleys rapidly descend to the lower reaches, 

 which are much broadened out, with flats so low that the deepening 

 processes no longer obtain. The general erosion-features of this 

 zone are those of a mountain-plateau, which has been dissected for 



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