356 PROF. SPENCER ON THE GEOLOGICAL AND. [ Aug. 1902, 
IV. Puystcat CHARACTERISTICS AND EROSION-FEATURES 
oF BARBADOS, 
Barbados, as already mentioned (p. 355), is scarcely more than 
20 miles long, with an area of 166 square miles. From the south 
and west the surface rises gently or in terraces, until an elevation 
of 1104 feet is attained near the north-eastern side of the island. 
Thence there is a more rapid descent towards the sea, which is 
encroaching upon this coast, undermining the softer formations 
and leaving great blocks of coral-limestone strewn along the shore. 
The surface of the island is covered and protected by White Lime- 
stones or ‘raised coral-reefs,’ except in the great valley descending 
from the height of land towards the north-eastern coast, where 
the underlying formations are the Scotland Sands and Oceanic 
Oozes, to be referred to again below. 
The surface of the high country i is the remnant of a base-level plain 
of erosion, with undulations of 25 to 40 feet. It is now a small 
zone, the margins of which (as on the Orizaba and Canefield Kstates) 
are dissected by gullies from 50 to 100 feet wide, increasing in 
depth from almost nothing to 50 and 75 feet, and extending for 
distances of 300 to 500 yards to the floor of a lower terrace, 700 
feet above the sea. In the interyening space, escarpments or sea- 
cliffs are carved out of the limestone-rocks. The ravine-features 
are repeated down to low levels, dissecting the edges of the terraces, 
but they diminish in size. At about 500 feet there are rather 
extensive terrace-plains. The terraces below the altitude of 400 feet 
(near St. Thomas’s Church) are bounded by sea-cliffs—the faces 
of higher ones. The ravine-features, in contrast with the undulating 
plain of the summit, suggest the recent elevation of the land. 
As the limestone-capping of the great Scotland Sands and the 
Oceanic Oozes on the highest part of the island is only about 25 
feet thick, it is not surprising to find in the Scotland Valley a series 
of gigantic ‘ wash-outs,’ or amphitheatres indenting the island to a 
distance of 3 miles inland, with a breadth increasing to 5 miles. 
V. THe Otper GrotocicAL Formations oF BARBADOS. 
Hitherto the geological formations of the island have been 
divided into three groups—the Scotland Beds, the Oceanic Series, 
and the Raised Coral-Reefs—which have been comprehensively 
described by Prof. Harrison & Mr. Jukes-Browne.* The Scotland 
Beds consist of great thicknesses of stratified sands but slightly 
coherent, which nevertheless form some bold cliffs along the en- 
croaching seashore. These are overlain by the Oceanic Oozes or 
marly clays of abysmal origin, the establishment of the character 
of which by Mr. Jukes-Browne is one of the most important con- 
tributions that have been made to West Indian geology, and indeed 
to the science, as showing the great changes of level of land and 
1 Quart. Journ. Geol. Soc. vol. xlvii (1891) pp. 197-250 & vol. xlvili (1892) 
pp- 170-226. 
