HILL: GEOLOGY OF JAMAICA. 29 



The pouch-like basin of Hector River is almost connected with the 

 northwest end of Clarendon Basin. At present the two are separated 

 by a low drainage saddle which has no direct outlet to the sea. Tlie 

 stream from which the basin takes its name rises from springs at its 

 west end, and sinks into the limestones to the east. Cave Valley in St. 

 Ann Parish, is four miles in diameter, and is also almost connected with 

 the Clarendon Valley, but is separated from it by a narrow limestone 

 ridy:e less than a mile in width. 



West of the Clarendon Basin similar circular depressions occur at 

 short intervals, such as those at Oxford, on the boundary of the parishes 

 of Manchester and St. Elizabeth ; the great headwater amphitheatre of 

 Black Kiver, St. Elizabeth ; the basins of Niagara River, the Mulgravo 

 and Ipswich sinks ; the Cambridge Basin ; the basins at the head of 

 Roaring River, and the King's Valley Basin near Jerusalem, the last two 

 of which open into the Savanna-la-Mar (Plain by the Sea). Of these the 

 Niagara, Mulgrave, and Ipswich basins have no drainage outlets. 



The basins above described constitute a line of depressions along the 

 central axis of the plateau. North of these in the high plateau region 

 of the parishes of Trelawney and St. Ann, are many other basins. The 

 most eastern of these, the Hampshire Valley, is about eight miles in 

 length and averages less than two miles in width. The bottom of this 

 basin barely reaches, if it does reach, the buried Blue Mountain struc- 

 ture, and has an elevation of about 400 feet. The surrounding hills rise 

 1,200 feet or more. To the west the Hampshire Valley is duplicated in 

 miniature by the Basin Fontabelle. Then comes the Queen of Spain's 

 Valley, a subcircular area five miles in diameter, whose bottom cuts 

 down to within 370 feet of sea level. Only a low gap divides the latter 

 from the great amphitheatre of Sunderland in St. James, which has been 

 captured by the headwaters of the Montego River. South of this is the 

 basin of Maroontown. 



There are many other smaller and less important sinks in the western 

 portion of the island, but those we have enumerated show the character 

 of these widely distributed phenomena. From our descriptions it will 

 be seen that many sinks have no outlet to the sea, although in their 

 bottoms may be found limpid streams of water. The barriers of others, 

 like those of Anchovy, Montpelier, Cambridge, and Chesterfield, lying 

 along Great River, have been broken by capturing drainage, become 

 connected with adjacent basins or coastal plains, and found outlets to 

 the sea by the union of several streams. Others, like the Clarendon and 

 St. Thomas valleys, were once entirely enclosed, but in later times have 



