Yol. 6$.~] THE CORAL-ROCKS OF BARBADOS. 331 



About a mile north-west of Haynesfield Quarry, near the head of 

 Blackman's Gully, is Blackmail's Quarry or Marl-hole. It is at 

 an elevation of about 900 feet. Dipping-beds are here well exposed, 

 and (when seen from a little distance) the section appears to consist 

 of a series of beds with a general dip at angles of 12° to 20° south- 

 eastward. To the west and above the quarry the limestone-beds 

 are horizontal ; but, as they approach the sides of the gully, they 

 gradually slope towards it. This may be a terminal curvature of the 

 beds, or may result from the landslips which from time to time have 

 taken place iu and near the quarry. On the western side of the 

 gully the beds, which everywhere consist of granular to marly lime- 

 stone-debris, dip east-north-eastward at angles of from 15° to 17°, 

 and lie on others sloping at 11° in the same direction. Near the 

 bottom of the gully the upper beds seen dip 12° south-eastward, and 

 are underlain by others which dip from 20° to 22° in the same 

 direction. Near by, below the road crossing the head of the gully, 

 the beds slope at 20° to the east-south-east. On the eastern side 

 of the gully are beds dipping at 18° eastward, succeeded by 

 others inclined at 27° south-eastward. A little east of the gully 

 the dip in these diminishes to 5° in the same direction, while 

 farther east the strata are horizontal. (See fig. 12, p. 330). 



The thickness of coral-rock is shown in the wells near Dukes to be 

 about 170 feet ; in the well at Haynesfield, sunk from a somewhat 

 lower level than the bottom of the quarry, there are 140 feet of 

 coral-rock ; while the wells near Blackman's, at a somewhat lower 

 elevation than the floor of the upper part of the gully, are about 

 180 feet deep. Hence these inclined beds, which might be held as 

 being somewhat in conformity with Prof. Spencer's theory, in 

 place of occurring (as that theory requires) near the base of the 

 limestone-succession, are relatively high in it. 



At Mount-Wilton Hill, at an elevation of about 1000 feet 



Pig. 13.— Section at Mount-Wilton Bill (altitude = 1000 feet). 



[Horizontal and vertical scales : 1 inch = 8 feet.] 



in a road-cutting, beds about 4 feet thick are exposed, dipping at 

 6° or 8° south-south-eastward and lying upon others inclined at 

 2° to the south. 



It is clearly evident that the beds showing considerable angles of 



