146 Proceedings of the lioyal Irish Academy. 



(p_ 24.) — ^^ Upper Basalt. — Although most of the district is capped 

 with sheets of Upper Basalt, the only good sections are to be found in 

 the almost inaccessible cliffs east and west of Bengore Head. Here 

 they form successive tiers of columns varying in size and sometimes 

 in position. These tiers indicate successive outflows of lava. The 

 most remarkable of them is the lowest of the series which caps the 

 iron ore deposits, and forms the Giant's Causeway." 



(p. 27.) — '■^ Rathlin Island. — The Tertiary volcanic rocks here are 

 well represented, and present very much the same section as they do 

 about Bengore Head on the mainland. The best sections are seen from 

 the sea, in the cliffs on the north side from Bull Point to the lighthouse. 

 " At Doonpoint there occui's a causeway in the Lower Basalt, and 

 the longitudinal section shows vertically columnar basalt having fan- 

 shaped and radiating columns of smaller dimensions blended into it 

 from the top, showing that the two sheets amalgamated before cooling. 

 Dr. Haughton notes of the rocks at Doon as follows : ' The curvature 

 of some of the pillars is continuous through 90°, and they pass from 

 the vertical to the horizontal position, exhibiting, however, a tendency 

 to break at the point of greatest flexui-e, which has caused most of 

 them to be broken off by the action of the sea.' " 



(p. 28.) — " The Dolerite of Pair Head is probably of the same 

 age as that at Portrush, but does not weather so rapidly. The Fair 

 Head sheet is remarkable for its enormous thickness, presenting, as it 

 does, an unbroken columnar face to the sea, near the ' Grey Man's 

 Path ' of 250 feet. 



"At the base of the basaltic cliff at Pair Head an intrusive sheet of 

 columnar basalt 70 feet thick occui's ; and in its extension it is met 

 with at Drumnakill Point, to the south, where the columns are 

 scattered in all directions." 



Mr. Symes regards the Dolerite of Pair Head as possibly the 

 latest volcanic protrusion in the county Antrim. 



(p. 31.) — "■Volcanic Vents. — One of the most remarkable volcanic 

 vents in the county Antrim is situated at the well-known island of 

 Carrick-a-raide and the adjacent coast, a fine view of which can be 

 had fi'om the celebrated ' swinging bridge.' This old neck cannot 

 be less than fi'om 1000 to 1200 feet in diameter, and is filled up with 

 massive, coarse, and tough grayish volcanic agglomerate, enclosing 

 large irregular masses and smaller fragments of basalt, basalt bombs 

 of all sizes, and chalk pieces occasionally." 



(p. 34.) — '■'■Peat Bogs and Alluvial Flats. — A deposit of peat projects 

 fi'om beneath the blown sand, and follows the slope of the strand for 



