History of the Island of Cuba. 201 



shown the general disposition of the old limestones. In 

 places as between Mata and Yumuri they form the north wall 

 of the coast. They cap the highest eminences of the island 

 seen by me, overlooking all other rocks, being alone over- 

 reached in altitude by the Sierra Maestra. Their close prox- 

 imity to the north coast and their abrupt protuberance above 

 the newer formations has an important bearing on the history 

 of the island as a whole. So extensive is this old limestone 

 formation and so abruptly does it rise above the coast, that if 

 all the coastal formations were stripped away or if the island 

 should subside for 100 feet its superficial extent would hardly 

 be perceptibly diminished, or its outline materially altered. 



The greater part of these limestones examined by me are, 

 as stated by Salterain and De Castro, of Eocene, Miocene, and 

 Pliocene age. In the Armendaris section near Havana, they in- 

 elude both Eocene and Miocene as has been asserted by De 

 Castro and others, and as shown by' my collections. At Baracoa 

 the upper layers are Miocene. De Castro, La Sagra and others 

 have recognized the Tertiary age of these limestones and their 

 distinctness from the modern reef rock. 



The l J ost- Tertiary Folding. — The chief feature which sepa- 

 rates the older limestone into a distinct system from the 

 modern reef rock is the stratigraphic unconformity between 

 them, and the fact that the former have undergone great fold- 

 ing and disturbance prior to the deposition of the latter, 

 which are always sub horizontal. In no locality have I seen 

 the newer reef rock folded or seriously pitched, but the older 

 limestone is frequently tilted at an angle of 45° or even verti- 

 cally as at Baracoa, and sometimes folded into anticlines as 

 back of Havana ; it presents every degree of folding and dis- 

 turbance in the numerous railway cuts between Havana and 

 Matanzas, at Villa Clara, Yumuri and elsewhere. In fact it is 

 seldom if ever sub-horizontal on the north coast, and the later 

 deposits are entirely unconformable with it. The general lay 

 of the old limestone is that of a low anticlinal whose axis cor- 

 responds with that of the island, accompanied by folds more 

 greatly developed along the north coast. This folding clearly 

 took place at or soon after the close of Tertiary time, and prior 

 to the deposition of the Post-Tertiary formations and eleva- 

 tions to be described, and indicates one of the most important 

 epochs in the geological history of Cuba, representing as it 

 does an orogenic disturbance not observed in continental North 

 American history. There is evidence at Havana that there 

 was some eruptive action at this epoch, dykes having been seen 

 there which protruded through the Tertiary. 



The Seboruco or Elevated Coral Reefs. — In strong contrast 

 with the older or Tertiary limestones is the modern group of 



