554 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.59. 



beds in this general region. I was interested in the possible presence 

 of tuffs in the series as an item for comparison with the fossil plant 

 locality in the Cordillera de Bogota of Colombia, but none were 

 observed. Naturally during a reconnaissance in a region of this sort 

 many beds of lignite or tuffs might be entirely overlooked even if they 

 were exposed. 



The plant-bearing series is underlain by several thousand feet of 

 black shale, from which a few marine fossils were collected, and which 

 is hence presumably of marine origin. From the facies of the plant 

 fossils I am inclined to think that the plant-bearing series represents 

 a complex of littoral, estuarine, and continental deposits, some of 

 the latter of palustrine origin and others detrital. 



In his account of the Cordillera de Merida, Sievers 2 described a 

 series of interbedded shales and sandstones with lignite and petroleum 

 at least 800 meters thick, overlying the Cretaceous limestones that 

 have been referred to the Albian stage. These he called the Cerro de 

 Oro beds. He had no paleontological data regarding their age. The 

 Cerro de Oro beds, probably a complex, have been compared with the 

 Trinidad beds named the Caroni series by Wall and Sawkins. 



The exact age of the Caroni series 3 has never been satisfactorily 

 settled, but probably will be when the collections from the Island of 

 Trinidad, which are accumulating in the United States National 

 Museum, are studied. W. P. Woodring, who monographed the Bow- 

 den molluscan fauna (Burdigalian), informs me that a cursory exami- 

 nation of the Trinidad Mollusca suggests a Miocene age for the Caroni 

 fauna. 



To the westward the Cerro de Oro series of Sievers is apparently 

 represented in the Cordillera de Bogota, Colombia by the Guaduas 

 formation of Hettner 4 consisting of bright-colored clays, ferruginous 

 sandstones, and conglomerates. Underlying the Guaduas are Cre- 

 taceous coal-bearing beds referred to the Guadalupe formation. 

 Karsten considers the former Tertiary and separated by an uncon- 

 formity from the Cretaceous, but Hettner is inclined to consider 

 both formations Cretaceous. 



Subsequent scattered references to this general region show the 

 presence of marine beds of probably middle Miocene (Helvetian) 

 age at several localities in Colombia, and others at Cumana, Vene- 

 zuela, which Douville correlates with the Burdigalian stage of 

 Europe. The recent studies of Vaughan and his associates in Cen- 

 tral America and the Antilles demonstrate that the upper Miocene 

 was a period of uplift around the perimeters of the Caribbean and 

 that there was profound deformation during Pliocene times. 



* Sievers, W., Die Cordillere von Merida, Geog. Abb., vol. 3, no. 1, 1889. 



« Guppy, R. J. L., Agr. Soc. Trinidad and Tobago, Proc, vol. 12, pt. 10, pp. 330-334, Oct., 1912. 



* Hettner, A., Die Kordillere von Bogota, Petermanns Mitt. Erganz., vol. 22, no. 104, 1892. 



