274 



There are, indeed, two more arguments for the conclusion that 

 Cuba has ever been a very inconstant region, at least since the 

 Tertiary. 



In the outset we reminded the reader that already Suess, Wichmann 

 and Martin had pointed out the analogy between the Antilles and 

 the southern Moluccas, wliich analogy is brought out in a similar 

 arrangement of the tectonic elements. Two points have been discussed 

 above to emphasize this analogy. In the first place the occurrence 

 of Red Radiolarites, so very typical of the Mesozoicum of the 

 Moluccas,, in the two extremities of the Antilles. In the second 

 place the conception that in the latter geological periods the Antillean 

 region was so extremely restless. It is known, indeed also of the 

 southern Moluccas, that their region was very changeable, and was 

 characterized by great instability in the relations of land and sea: 

 also there the formation and the denudation of mountains took place 

 in such rapid succession, that it is difficult to disentangle the develop- 

 ment of the geological history. We may add even one more detail 

 in comparing the instability of the Antillean region with that of 

 the southern Moluccas. In the Antilles it struck us that in one and 

 the same island Radiolaria-deposits occur at least in four different 

 levels. Why, also of the island of Rotti, near Timor, Bhouwer has 

 described^) Radiolaria-bearing deposits in three totally different levels: 

 Upper Trias, Malm and Tertiary. 



Utrecht, May 1922. 



sea, anyhow in a sea of considerable depth. In the Avhite marls of La Gienaga, 

 where many Globigerina and also numerous Radiolaria occur Sanchez-Roig (I.e.) 

 has found numerous teeth of Selachii. A large number of these teeth (though by 

 far not all) display the peculiarity that only the enamel of the teeth is left, while 

 the dentin has completely disappeared. This state of preservation is exclusively 

 characteristic of Selachii-teeth that are encountered in the deepest sea and in 

 deepsea deposits. 



Gf. MoLENGRAAFF and Beaufort, Proceedings XXIX, 1921, p. 677—692. 



^) H. A. Brouwer, De Nederlandsche Timor Expeditie, III, 1921. Geologische 

 onderzoekingen op het eiland Rotti. 



DESCRIPTION OF THE PLATES. 

 Fig. 1. White Radiolariamarl. Older Habanaformation. X 26. 

 Fig. 2. Red Radiolarite. Vifiales. X 26. 



Fig. 3. Silicious rock with Radiolaria and Sponge-spiculae. Bacuranao. X 26. 

 Fig. 4. Geological Sketchmap and transverse profile of the vicinity of Habana. 



— . — . — Railways. 



ABC-CD Line of Profile. 



S. Serpentine. 



D. Quartzhornblendediorite. 



A. Petroleum Rigs. 



