58 TRINIDAD. 



of micaceous slates, sandstones, limestones, and slates, which are 

 the constituent strata of the northern littoral range. 



They propose to describe as Older Parian an indurated for- 

 mation of lower cretaceous age, occurring in the central range. 



They designate as Newer Parian that series of tertiary strata 

 which comprises the whole of the southern division of the island. 



The most prevalent beds of the Caribbean group consist of 

 mica slates with layers of quartzose matter, at Saint Ann, for 

 instance. There is a considerable variety of sandstones. Cal- 

 careous rocks are represented by two varieties in this group, 

 viz. : crystalline limestones, contained in the slates, and alter- 

 nating with same, as at Monos, for instance ; and compact lime- 

 stones, either completely unconnected with the schistose group, 

 or only associated with its upper strata. The former sometimes 

 occur in massive beds, varying from white to blue in colour. 

 The compact limestones form a portion of the Laventille hills 

 and several of the islands in the gulf. Point Gourde is entirely 

 formed of that variety. It occurs again at Oropuche, at an 

 elevation of 2,000 feet. 



The Older Parian group consists mainly of a great variety 

 of sandstones ; of strata composed of an argillaceous base with 

 equivalents of free silica. When combined with a given pro- 

 portion of silica, it represents a certain degree of hardness, and 

 forms a species of clay rock, which may be termed Argiline. 

 This substance is extensively quarried at the Naparima hill, and 

 is used, under the name of gravel, to make up the roads in 

 Naparima and some neighbouring districts. 



The Newer Parian group may be said to reach, northward, 

 the rivers Caroni and Oropuche ; it occupies the whole of the 

 southern division of the island — more than two-thirds of its 

 entire surface. It comprises a succession of clays, shales, loose 

 sand, limestones, calcareous sandstones, and marls. 



For facility of study, this group has been divided by Messrs. 

 Wall and Sawkins into five series, viz. : (1) ,the Caroni, or Carbona- 

 ceous series, which extends from Pointe Noire, on the eastern 

 coast, to the gulf. The tract it represents is but slightly 

 elevated above the sea near the gulf. 



2nd. The Naparima Marl. This series is formed of strata 

 composed of clay, marls, and calcareous sands. A considerable 

 and the best portion of the cultivated district of Naparima 



