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. The 
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 
ridge 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 River, St. Elizabeth ; the basins of Niagara River, the Mulgrave 
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 drainago 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. Am, 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 
comnected 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 
