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THE LESSER ANTILLES
Belair (in the center), at an altitude of 600 feet, the tuffs of which the hills are composed are covered with layers of a shallow-water foraminiferal limestone, from ten to twenty inches in thickness. It therefore appears to consist of layers of volcanic ash which were deposited in the sea, and afterwards covered
Fig. 49—Diagram of a partly submerged cliff.
with the shallow-water deposit. Later this was subjected to upheaval, with the resuit that part of the limestone was raised to at least 600 feet above sea level. The rest of the Grenadines are geologically much like Carriacou, but appear to lack the limestone capping of that island. "25 None of the islands now have the forms of young volcanic cones; ail appear to be residual forms of subdued outlines, except for occasional sharp, necklike peaks, and abrupt, spur-end sea cliffs. The larger members have irregular shore lines, with open valley-head embayments separated by cliffed headlands. Soundings on a large-scale chart suggest that the cliffs plunge below sea level. The abrupt change not infrequently seen from a steep cliff at the end of 25 A. H. Clark: Birds of the Southern Lesser Antilles, Proc. Boston Soc. of Nat. Hist., Vol. 32, 1905, pp. 203-312; reference on pp. 213-214.