REPORTS. 19 



Vrangue Brickfield. 



In the new exposure produced by the cutting back 

 of the face of the clay in the upper pit, several pebbles 

 have been found at a depth of 7 or 8 feet, but still in 

 the upper loam. In the lower pit a new face has also 

 been exposed. The decomposed rock underlying the clay 

 shows very distinct curved veins dipping west, that is, 

 away from Mont Arrive outcrop, while the angular 

 pieces of stone in the clay occur in more or less distinct 

 layers or strata, also dipping west. These strata are cut 

 off by the surface soil, showing that considerable denudation 

 has taken place since their accumulation. 



ROCKS. 



St. Andrew's Brickfield. 



The Quarries in this locality, which are noAV being 

 somewhat extensively worked for road metal, both for local 

 use and exportation, have been revisited. In the western 

 quairy the gneiss, which is blue and of the Richmond type, 

 is very tough in places, but in other places has a schistose 

 tendency, owdng to the occurrence of hornblendic laminae. 

 The eastern quarry contains a finer grained rock of a dark 

 blue colour with white felspathic streaks. It w^as described 

 by the owner as a talvane (by which term intrusive veins 

 of close-grained diorite are generally meant), but there 

 can be no doubt that the rock belongs to the gneissic forma- 

 tion, and its gradual passage to the form found in the 

 other quarry can be traced. 



Quarry^ near Le Tertre^ St. Andrew's. 



The rock here is also called a talvane, and is a vein 

 intrusive in the gneiss, dipping north-east at a small angle, 

 and not exceeding 8 or 10 feet in width, but forming sub- 

 sidiary off-shoots which are also worked. This vein is partly 

 composed of quartz felsite, but passes into the ordinary 

 blue talvane. On the east coast and elsewhere in this Island, 

 the quartz felsite veins cut the diorite veins, and are con- 

 sequently of later date. In the present case, the vein would 

 seem to be one of the quartz felsite series, which in its 

 passage had caught up and incorporated a quantity of diorite. 



Les Quartiers, St. Sam,X)Son's. 



In the lane at the back of Les Quartiers, an inclusion 

 of diorite is seen intersected by veins of the surrounding 

 red granite. This granite is doubtless an outlier of the 

 Cobo Mass. 



