272 



this respect between Cuba and some of llie other Aniilles finds an 

 explanation in liie above. 



Indications of the homogeneity of Ihe row of Antilles can also 

 be found in the older formations of Cuba. As stated previously, of 

 late years Malm-ammonites have been found jiear Vifiales, in the 

 most western part of Cuba. These Upper-jurassic layeis, which dip 

 away to the North at a rather small gradient, are overlain by thick, 

 old-looking giey limestones with intermediate layei'S of sandstones, 

 which, therefore, are probably to be referred to the Cretaceous 

 system. In one place I foiind in these limestones small nests of red 

 chert; under the microscope this red chert appeared to be a true 

 Radiolarite, very much like the Radiolarites so widely diffused in 

 the mesozoic rocks of the southern Moluccan-cordillere (fig. 2). The 

 geological institute at Utrecht possesses a number of rocks from the 

 islands of Curacao, Bonaire and Aruba, collected by Dr. I. Boi.dingh. 

 Among the rocks from Bonaire and Curacao it was not difficult to 

 recognize Radiolarites — piobably mesozoic — bearing close resem- 

 blance to those from Cuba.') This is not all. In the coral-limestones 

 of the Yumuri-cleft near Matanzas coarse clastic material was found; 

 boulders to a maximnm of 7 mm. in diameter. Four of them were 

 ground, of which two ap[)eared to be red radiolarites like those 

 found to the north of Vifiales, while in our days mesozoic sediments 

 are lacking in this part of the island. 



It is evident, therefore, that such a peculiar sediment as the mesozoic, 

 red radiolarite is found at the extiemities of the Antillean region: 

 in the most western part of Cuba and in Bonaire and Curac^ao. 

 This, no doubt, warrants the a8sum[)tion that the Antillean region 

 is one continuous- whole, i)arts of which, in spite of their different 

 appearance, have many features in common, that point to an 

 historical homogeneity. 



From the occurrence of much volcanic material in the whole 

 tertiary of Cuba, in the neighboui-hood of which no volcanoes exist 

 any more, we may conclude that the island must have been subject 

 to great geological disturbances in recent times. A similar conclusion 

 may be deduced from the great abundance of boulders of cretaceous 

 Radiolarites in the miopliocene of the Yumuri-cleft, as these boulders 



•) K. Maetin, Bericht über eine Reise nach Niederl. West Indien, II, 1888, 

 p. 28 and 73 and J. H. Kloos, Samml. Geol. Reichs-Museums, Leiden II, 1, 1887, 

 already demonstrated the occurrence of Radiolaria-bearing rocks in Guragao and 

 Bonaire. From their descriptions it is not evident, however, that we have to do 

 here with typical Radiolarites, which at that time did not receive so much 

 attention from geologists as nowadays. 



