LATER TERTIARY (MIOCENE AND PLIOCENE). 803 



These three members are so intunately united that their separation is purely arbitrary. 

 Beds of sandstone are found in the shale, and beds of shale extend far down into the lower 

 member. Very few if any fossils have been found in the sandstone, though the gravels of 

 Angostura yield shells abundantly, in connection with fragments of fossilized wood. The 

 same species of fossils occur in all parts of the series, and I have collected from a bed of sand- 

 stone at the very summit of the Mao gravel a series of shells identical with those embedded in 

 the rocks of the " nonfossilif erous sandstone" plain east of Guayubin, and which are found 

 abundantly in the blue shale of the Gurabo, Amina, or Verde. j 



Fossils are not regularly distributed either vertically or laterally, but seem to occur in 

 colonies. The blue-shale bluflf under the city of Santiago, 60 feet high from the level of the 

 river, does not show a single streak where they are e^ver abundant enough to repay the trouble 

 of hunting, although isolated shells occur throughout. At Punal, but a few miles off, near the 

 Rio Verde, shells and corals abound. The same irregularity exists throughout, and although 

 there is but httle change in the species of the MoUusca in their vertical range, there is a marked 

 difference between the eastern and western ends of the basin. Shells that are absent or scarce 

 on the Verde are common on the Gurato and westward, and vice versa. The corals found in 

 the shale are almost always of the cup forms, while the massive corals are almost exclusively 

 confined to the upper beds and are particularly abundant on the north flanks of the Samba 

 Hills. In all the shale beds and to the extreme top of the series Foraminifera occur and in some 

 places are found in great numbers. They are not very numerous in species, probably not 

 exceeding half a dozen. The Orbitoides ranges throughout all the strata and is not only found 

 wherever any other fossil occurs but is often, especially in the higher beds, the only recogniza- 

 ble organic remains. It has more than once proved of great value to me in distinguishing these 

 limestones from the overlying post-Pliocene calcareous beds. 



With one or two small exceptions all these rocks are entirely unaltered. On the southern 

 limit, in contact or nearly so with the underlying Cretaceous in the vicinity of the Bao River 

 and on the X^-qui, the coarse sandstones are slightly modified, though still retaining their strati- 

 fication and mechanical structure unchanged. On the Yaqui at Tabera this rock is highly 

 uptilted and slightly contorted, as will be seen by reference to the description of the locality. 

 Also in the northern range a similar slight metamorphism occurs southeast of Puerto Plata. 



Gabb then discusses the geologic age of the West Indian Tertiary rocks and 

 gives the age of many fossils, including 217 supposed extinct species and 97 known 

 to be living. He concludes, "We are therefore at or near the top of the Miocene." 



F 17-18. CUBA. 



T. W. Vaughan has contributed to this work the following notes on the later 

 Tertiary of Cuba: 



An extremely interesting fact in the Cuban stratigraphy is that, so far as we at present 

 know, there is absolutely no true Miocene on the island. The Miocene as described by De Castro, 

 Salterain, and others is now referred to the upper Oligocene. From the evidence now before 

 us, it seems most probable that during Miocene time none of the now existing portions of the 

 Island of Cuba were submerged beneath the ocean. 



The data regarding the presence of Pliocene strata are unsatisfactory. The only data on 

 which we could base a conclusion are derived from the notes and collections of William Palmer. 

 In the western part of Havana, on the Calle Infanta, opposite Castillo de la Punta, Palmer 

 collected fossils from a quarry in soft white limestone. The bottom of the quarry is about at 

 sea level. According to Palmer the same formation extends to approximately 60 feet above 

 sea level. The fossils obtained from this locality may be Pliocene, though it is probable that 

 they are Pleistocene. The limestone which is being quarried between Almandares River and 

 Camp Columbia, on the north side of the road, may be of Pliocene age. 



