GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 287 



are common to both. Dr. Paul Bartsch tells me that the Isle of 

 Pines is only "a chunk of Cuba" and that its land Mollusca represent 

 a faunal area as closely related to the faunal areas of Cuba as are 

 the different faunal areas in Cuba to one another; that is, faunally, 

 the Isle of Pines is simply a portion (a faunal area) of Cuba. There- 

 fore, it is clear that the Isle of Pines has been severed from Cuba in 

 the latest Pleistocene or Recent geologic time. 



Practically aU the Cuban shore line has now been considered except 

 that on the north side of the Province of Pinar del Rio, within the 

 Colorados Reefs. Guadiana Bay is a nearly typical estuarine em- 

 bayment, while slighter embayment of other stream mouths is 

 indicated, and lines of islands extend seaward from some headlands. 

 The shore line clearly indicates submergence. Mr. J. B. Henderson 

 and Doctor Bartsch, however, tell me that there is positive evidence 

 of minor uplift west of Guadiana Bay. ^ 



The Cuban shore line as a whole shows evidence of Recent or latest 

 Pleistocene submergence, and this submergence has influenced the 

 modern coral-reef development. 



Regarding the amount of Recent submergence of the Cuban shore 

 line, reference to the table on page 282 shows that there is close ac- 

 cordance in the depths of the channels or harbors, except certain 

 ones that will be discussed later. These indicate that prior to the 

 last submergence the land stood about 100 feet or slightly more, 

 about 20 fathoms, higher than at present. The amount of emergence 

 would establish a broad land connection with the Isle of Pines. 



The discrepant harbors are Nuevitas Bay, which shows an excess 

 of only about 27 feet, Nipe and Tanamo bays, and the channel 

 leading from Livisa and Cabonico bays, on the north coast, and 

 Cienfuegos on the south coast. The harbors with the discrepant 

 depths on the north coast all occur on the north side of the Province 

 of Oriente and at the eastern end of the Province of Camaguey. 

 They seem to indicate deeper submergence than at other places and 

 that the submergence has not been uniform in amount for the entire 

 coast. However, the depths do not contradict a Recent rise of sea 

 level to an amount of about 20 fathoms. The harbor of Cienfuegos 

 would be expected to be abnormal, for the fault line which runs 

 northward from Cape Cruz intersects the shore line at its mouth 

 (see text-fig. 15). It is possible that structural relations have also 

 influenced the depths in the other harbors and channels that are 

 discrepant. Regarding these it wiU be said that except Nuevitas 

 Harbor they occur within a linear distance of 31 miles. Nipe Harbor, 

 the westernmost of the group, lies on the north side of Loma de 

 Mulas, while it, Livisa, Cabonico, and Tanamo harbors all are on 

 the north side of Sierra Cristal. 



1 Henderson, J. B., Cruise of the Tomas Barrera, pp. 161-164, New York, 1916. 



