GEOLOGY OF PART OF CUBA. 215 
ciently below it to admit of the passage of a boat, when steered with caution. Their 
arrangement is not unworthy of notice, being so disposed as to offer much less resistance 
to the landward motion of the swell, than would be anticipated, They present, not a 
solid surface, a vertical obstacle, as has been often stated, but a partial obstruction to the 
water which rushes through or between numerous coral groups. ‘This is owing to their 
being arranged somewhat in rows or tiers; not parallel with the reef, but disposed at 
right angles to it: and admitting the broken waves to pass amidst them, into shoal water. 
Thus, for years, perhaps for ages, the thundering surf may fall harmlessly upon and 
amongst these beautiful productions of nature. The effect of the barrier, according to 
this arrangement, is far more effective and permanent, as a breakwater, than if it had 
presented the solid, abrupt wall which a reef is commonly represented to be. 
Bordering the beach or shore, next the Baxo, is the older reef, furnishing ample evi- 
dence of a change of level. This, for awhile, appears as a low perpendicular cliff. It 
then passes obliquely inland, to westward. Between it and the present beach is now a 
ridge of low sand-hills, which are thickly covered with bushes, such as the wild fig, the 
cocoa plum, the sea grape, and a few aloes, palmettos and creeping shrubs. Like the 
older limestones, this rock is deeply honeycombed, and contains large detached mean- 
drina, madrepores, porites, caryophillia, millepora, astree and others; intermingled 
abundantly with spines of echinites and well preserved, but colourless, shells. In this 
old coral rock we notice extensive fissures, running sometimes many hundred feet, pa- 
rallel with the coast line. These fractures may have resulted from the same cause which 
heaved up the old reef to its present elevation; and then again the latter may have been 
due to, or influenced by, the movement which, at a distant day, threw the entire mass of 
substrata into its inclined position, as we now see them. Coral likewise occurs at a 
much greater elevation on the plains of the interior. Similar phenomena occur on the 
shores of the island of Jamaica.* 
Before we quit the subject of coral reefs, in these latitudes, we may make mention of 
that remarkable chain of keys, which stretches seemingly in a line, parallel with the 
north coast of Cuba. These Cayos, whose numbers seem interminable, are for the most 
part, covered with a dark vegetation. Some of them are a mile or two long; others are 
much smaller, and the trees, by which they are covered, seem to rise out of the sea. 
Groups, and clumps, and groves of trees, appear as if growing in the water. Occasion- 
ally a single tree appears the solitary occupier of its own little island.t From the Cruz 
del padre to the Punta Icacos, and still further west, is an almost uninterrupted chain of 
wooded keys. It occurs at the distance of a few miles from the main land, to which it 
seems an important protection; at the same time affords the finest fishing grounds, of 
which the aboriginal Indians well knew the value, 
THE MINERAL REGION OF GIBARA.—COPPER. 
Discovery of Copper Lodes.—Previous to the year 1830 the existence of copper lodes 
on the north-east side of Cuba was unknown. They were first discovered in the savanas, 
* De la Beche, Transactions of the Geological Society of London, Vol. II., part 12. 
+ On the old Spanish maps this group is named the Jardin del Rey. 
SSE 
