198 li. J. L. Guppy — Bock-horings, Trinidad. 



The Sangregkande Bokings. — Pakt II. 



Since writing Part I of this paper I have been favoured by the 

 Hon. AValsh Wrightsou, C.M.G., Director of Public Works, with 

 reduced diagrams of the three borings made at Cunapo, near 

 Sangregrande, for the purpose of ascertaining particulars relative to 

 the coal-seams in that neighbourhood, and with access to the samples 

 of the cores brought up. These extend our knowledge of the 

 geological conditions very considerably. In Part I of this paper 

 I gave a description of the rocks and fossils of boring No. 3. The 

 diagram of this boring (Plate VII) shows that from 200 feet to the 

 bottom of the boring at 600 feet the composition of the strata is 

 nearly uniform, being the foraminifeial sandstone I have described. 

 This deposit probably recurs in boring No. 2 (82 to lo2 feet) and 

 boring No. 1 (90 to 486 feet). At 12 to 18 feet in boring No. S 

 there is an ancient river-bed with very hard compact cherty stones, 

 similar to those found in some of the existing river-beds. I do not 

 think that the material of these stones exists anywhere in the form 

 of a continuous layer or stratum, or, if they do, such layer is not of 

 any great extent. It probably exists as lenticular or nodular 

 masses varying in size, and when the containing softer material is 

 carried off these hard stones remain in the river-beds. So with 

 the Naparima rocks near Sanfernando, the harder masses remain 

 heaped upon the beach, while the softer material in which they were 

 imbedded is carried away. 



With the exception of two small seams, one of 6 inches at 29 feet, 

 and one of 2 inches at 89 feet, no coal was encountered in any of the 

 borings. Nevertheless, the composition of the strata at the top of 

 each of these borings indicates perhaps littoral conditions or at least 

 shallower water than the material deeper down in the borings. The 

 bed underlying the coal-seam at 89 feet in boring No. 1 is a soft 

 black argillaceous rock with very fine sand, impressions of plant 

 remains, and small bits of coal. This stratum, less than 3 feet 

 thick, is confusedly bedded, and represents, I think, the bottom bed 

 and very beginning of the coal series. 



The problem of the relation of the strata pierced by these borings 

 to the coal-bearing series is now before us. These strata are, with 

 a slight exception, of marine formation : are they above or below the 

 coal series ? 



So far as we can judge from the information now at hand, it would 

 seem that they are below. If they were above it would follow that 

 there had been a depression of land since the deposition of the coal 

 in order to admit of the deposit of a marine formation above it. But 

 taking all the known circumstances into account, I think this unlikely. 

 There was probably a movement of upheaval continued throughout 

 the Miocene period which raised the Cretaceo-Tertiary series of 

 Montserrat (including the Manzanilla Eocene formations) above the 

 level of the sea, leaving an arm of the sea between the Montserrat 

 Eange and the Parian Range. Into this channel the river Guarapiche 

 (taking its rise and upper course in Venezuela) emptied itself, and 



