196 REPORTS. 



REPORT OF THE GEOLOGICAL SECTION. 



SUPERFICIAL DEPOSITS. 



In the excavation of the site for the new schools in this 

 locality > superficial deposits from 6 to 8 feet thick have been 

 exposed. They consist of yellow loam and sand in alternating 

 layers (Route Isabelle type). These lie on pseudo-stratined 

 decomposed rock, which, in the sections across the dip, is 

 seen to merge, by a gradual curve, into the undisturbed 

 decomposed rock. 



St. Andreivs Brickfield. 



The deposits in the field at the corner of the road leading 

 to the Wesleyan Chapel, which are worked for brickmaking, 

 are very similar to the above, the sandy layers being, however, 

 less distinct, and the curvature of the decomposed rock more 

 plainly exhibited. 



Sark. 



Mr. G. T. Derrick reports a section near Dixcart Hotel, 

 shewing 8 feet of deposits of the same type as the above, 

 i'e., interstratified sand and clay, some of the sandy layers 

 being 3 inches thick, but the sand is hardly so pure as at 

 Route Isabelle ; the clay being rather more plastic. It is 

 somewhat remarkable that in the adjoining lane leading from 

 the hotel to the plateau above, no trace of superficial deposit is 

 found, only decomposed rock being exposed on both sides of 

 the lane. In all the above cases, and in most others of similar 

 deposits, the situation is the slope on the side of a glen or 

 valley. There is generally no opportunity of ascertaining 

 whether the deposits continue under the bottom of the valley, 

 but in some cases they certainly do not. The valleys seem 

 to have been deepened since their deposition and the surface 

 has been considerably modified by erosion. 



ROCKS. 



Houmet Paradis. 



In the rocks exposed at low water on the east side of 

 this islet, granite, similar to that at Fort Le Marchant and 

 Roque Balan, L'Ancresse, is seen. It is intrusive in the 

 diorite, producing in places very distinct veins, and in others 

 blending in various proportions. This granite seems to be 

 the margin of a considerable area covered by the sea. 



