32 NOTES ON THE GEOLOGY OF THE BAHAMAS 



West of Nassau, on the beach, are many places where the waves 

 have cut narrow passages into the rocks and ground the fragments 

 into sand. There are also a number of " pot-holes " ; these were circu- 

 lar in horizontal sections, and the bottom and sides were smooth. They 

 contained the worm coral heads that had evidently been the means of 

 making the holes. 



On the beach of the cays north of Nassau great blocks of coral rock 

 are seen that have been dislodged by the waves, and in some places 

 fresh fractures show where large fragments have been broken off. On 

 the south side of the cays the erosion is different. Here the water is 

 quiet and eats slowly under the rock, so that a projecting ledge is 

 formed that marks the height of the tide. 



At some places on Andros, as at Fresh Creek and Nicol's Town, 

 the shore is undermined, and great slabs in places have fallen, thus 

 making large cracks. Similar cracks are found inland higher above 

 high-water mark, and have evidently been formed in the same manner 

 as those on the shore. Where the edges of the crack were in contact 

 they had been firmly cemented together, and at intervals along the line 

 of the crack were numerous large holes that had evidently been worn 

 out by the action of rain-water running over the edge. Leading into 

 these holes were channels almost as perfectly formed and rounded as a 

 tin gutter. 



The erosion of the surface will impress every one that visits the 

 Bahamas. Sharp jagged points project so as to make walking tire- 

 some and annoying. Although there is some sand near the beach west 

 of the Barracks at Nassau, there axe no great moving masses such as 

 Heilprin describes as being found in Bermuda.^ ' 



In some places, as on Goat Cay, near Fresh Creek, Andros, the 

 surface is eroded in a peculiar and striking manner. There the rock' is 

 worn so as to leave vertical cylindrical masses two or three feet high, 

 some connected below or halfway up with each other, others separate. 

 Their sides and tops are pitted and eroded, so they have evidently been 

 affected by atmospheric agencies. On the ocean side of this cay the 

 erosion from the action of the surf was so exceedingly rapid that the 

 rock remained a light yellowish color instead of the dull or dark gray 

 it commonly assumes. The form the rock here presented was even 

 more striking than the cylindrical masses described above. It was 



' "The Bermuda Islands,'' p. 31. 



