the Counties of Mayo and Sligo in Ireland. 157 



Section at Moyne^ north-west of the Abbey. 



Ft. In 



Oolite 3.5 



Black Limestone, containing-) 

 Cirri, clayey and friable .... J 



Sandstone in beds 5 



White Shale 2 



Sandstone 1 4 



Sandstone and Shale, in thin 



layers J 



47 4 



Ft. In. 



Brought forward 47 4 

 Alternate beds of Shale and ] 



Limestone J 



Calcareous Sandstone 1 10 



Shale 8 



Argillaceous Limestone 1 8 



Shale 1 8 



Ochrey Sandstone 1 o 



57 10 



There is a striking resemblance between these grit and shale beds, and those which accompany 

 coal ; but they lie decidedly below the great limestone, over which all the Connaught coal district 

 is placed. Their total thickness may be estimated at 1700 or 1800 feet. 



The most instructive sections are exposed along the coast from Ross, near Killalla, to Port 

 Conoghrea, where the quartz rock is first seen. In many quarries, the surface of the grit beds 

 exactly resembles a sandy beach deserted by the tide, presenting the same waved, ripple marks. 



Beneath the varied succession of strata, which underlie the carboniferous limestone, is gene- 

 rally found the 



D. The Old Red Sandstone and Conglomerate. 

 This rock occurs uniformly along- the base of the Ox Mountains, both on 

 the north and south declivity ; but, at the shore on the confines of Erris^ 

 where the intermediate and primary strata join, it has perhaps either never 

 existed, from the absence of the causes which influenced its deposition else- 

 where, or it has become identified with the lower portion of the grit, by a 

 change in the grain and texture. In general, the strata are very distinct, 

 though composed of large pebbles of quartz, jasper, and primary schists im- 

 bedded in a tenacious cement. The argillaceous soil formed by the decom- 

 position of the matrix of the conglomerate, is stiff, cold, and sterile. I have 

 not observed any organic remains. The conglomerate graduates, in many 

 places, insensibly into the subjacent quartz rock, especially on the south de- 

 clivity of the Ox Chain, where the two formations lie conformably on the 

 inferior strata ; but on the northern slope, the conglomerate rests on the 

 edges, or outcrop of the older beds. This position may be very distinctly 

 seen at the foot of Knock-a-Chree, above Drimnagoole, where the mica slate 

 dips to the south, to which point the beds of old red sandstone rise, lying un- 

 conformably on the edges of the schist, and followed by the grit, shale and 

 carboniferous limestone, in regular and parallel succession. In Glen Co, on 

 the banks of the Owen more River, in Erris, this rock emerges from under 

 the series described by Mr. Griffith, and lies on the quartz rock, which pre- 



