278 BULLETIN OF THE 



must have been oscillatory. It is easy to imagine evidences of subsi- 

 dence, but to prove them is difficult. Geikie has said : — 



" It is more difficult to trace a downward movement of the land, for the evi- 

 dence of each successive sea margin is carried down and washed away or covered 

 up. . . . The student will talie care to guard himself against being misled by 

 mere proofs of the advance of the sea on land. In a great majority of cases 

 where such an advance is taking place, it is due not to subsidence of the land, 

 but to erosion of the shores. . , . The encroachment of the sea upon the land 

 may involve the disappearance of successive fields, roads, houses, and villages, 

 and even whole parishes, without any actual change of level of the land." ^ 



I failed to find any traces in the upland areas of recent deposits which 

 would indicate any submergence whatever. The soils, especially the 

 " Tierra Colorada," are everywhere residual, and nowhere did I observe 

 any that could be attributed to transported material or overplacement 

 of alluvial matter, and particular care was taken to look for such evi- 

 dence. De Castro reports extensive upland alluvial deposits in the 

 region of Puerto Principe, but gives no evidence whereby we may deter- 

 mine whether they were produced by inland deposition or by submer- 

 gence of the land to sea level. Neither do the rivers show any revival 

 or other evidence of such subsidence, but all have continuous down- 

 ward cutting sections. 



Whether there has been recent subsidence immediately preceding the 

 deposition of the elevated coral reef of soboruco, whereby the circular 

 harbors were produced, as Crosby alleges,^ is also a point which is diffi- 

 cult to determine. In support of his position he points out the structure 

 of the circular harbors and the great thickness of the older limestones, 

 which he believed to be ancient reef rock. 1 have endeavored to show 

 on a previous page that there is no evidence to support the theory that 

 the older and elevated limestones were coralline reefs in origin, and 

 hence it is not necessary here to discuss this testimony further. 



Concerning the circular harbors, however, I must confess that Mr. 

 Crosby has some reason for his argument, although the evidence may 

 be more strongly interpreted to indicate elevation. Concerning these 

 harbors, he says : — ■ 



" The coast of Cuba is probably not rising now, at least not at all points. 

 On the beach near Baracoa the erect stumps of large trees may be seen, 

 standing where they grew, near the low-tide mark. The numerous harbors 

 of Cuba are nearly all formed on one plan, of which Baracoa is a good ex- 



1 Text-Book of Geology, p. 261. 2 Qp, dt. 



