HILL: GEOLOGY OF JAMAICA. 173 
Antillean history, representing as it does the commencement of a con- 
Secutive sequence of events from late Cretaceous time to the present. 
It is clearly the débris of a vast volcanic extrusion which in late Creta- 
eous time completely obliterated and revolutionized all the antecedent 
relief, The age of this eruptive epoch is clearly late Cretaceous. 
In San Domingo,! St. Thomas,? and Porto Rico, these formations are 
Associated with limestone beds and Cretaceous fossils in part, resembling 
in species and faunal associations those of Jamaica, and in part contain- 
ing species not found in the latter island. In Cuba? both the Jamaican 
and continental types of Cretaceous faune are found. 
The data seem to point to the fact that the whole region of the Great 
Antilles proper, including the Virgin Islands, St. Croix, and St. Dar- 
tholomew, was the site of active vuleanism in late Cretaceous time. 
The extent or outlino of the Antillean volcanic disturbance of late 
Cretaceous time cannot be delineated. It is an important fact that no 
Cretaceous fossils or formations analogous in age to the Blue Mountain 
Series are known to ocour in the Caribbee Islands proper and Barbados. 
There is slight evidence, however, that the Cretaceous rocks and fossils 
9f Central America are of the Antillean facies. The sparsely developed 
Üretaceons formations of Central America known to occur only in the 
Chiapas- juatemala district as reported by Sapper,‘ and the San Miguel 
! From San Domingo, Gabb has reported a serrated oyster, Trigonia, Turritella, 
Ancillaria, Pugnellus (?), Mactra, Pterocera, Cucullea, Lima, an Ammonite, and 
Baculites from beds of limestone in the River Maniel. Tippenhauer (Op. cit., 
Dp. 84, 85) gives the following note on the Cretaceous of San Domingo: “ The 
San Juan valley on Samana, the Pico Gallo on the Central range, the region of 
Tablasas in the south, are types of this secondary formation. ‘These masses, up 
to 800 m. thick, form a zone around the highest ĉlevations. Besides vast, com- 
Pact gray-blue and dark limestone masses, there occur marl and sand strata. 
Che ordinary fossils are Hippurites, Nerinea, and Actwonella. The compact 
limestone often encloses Radiolites up to seven feet long. In places the limestone 
Mas been strongly metamorphosed by the influence of plutonic rock ; in such cases 
! resembles serpentine, is exceedingly dense, and has lost almost all its fossils 
Y obliteration; it is also for the most part whiter." 
2 The beds of St. Thomas, according to Cleve, contain the fossils Nerina, 
Aetwonella, Ammonites, Trochus, Peetuneulus, Limopsis, Opis, Venus, Astarte, 
Corbula, etc., of Cretaceous age. Geology of the Northeastern West Indian Isl- 
ands, 1871, p. 5. 
3 In Cuba the Cretaceous fossils, according to Salterain, are Holectypus, Discoidea, 
assidulus, and Codiopsis; and, according to G. F Matthew, Ostrea, Exogyra, 
Noceramus, from a locality in the Cienfuegos road, and a Hippurite limestone com: 
Posed of Caprinella and Caprotina, corals, a large Oliva, a Conus, an oyster of the 
Ype of O. eristati, Echini, and sponges from Limones. 
\ Grundzüge der physikalischen Geographie von Guatemala, p. 9. 
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