138 Proceedings of Philosophical Societies. [August, 



June 19. — The reading of Mr. Wearer's paper was concluded. 

 The district described in this paper is bounded on the E. by 

 the Irish channel, and on the S. and W. by the mountains which 

 confine the Suire and Shannon, and on the N. by the hills of 

 South Meath, Cavan, and Longford, and by a line produced 

 from thence to the bay of Galway. It is about 100 Irish miles 

 from N. to S. and 60 to 90 from E. to W. comprehending about 

 4- part of the island. It may be divided into primary tracts, 

 comprehending 



Granite, 



Mica slate, 



Clay slate, 



Transition tracts, 



Floetz tracts, and 



Alluvial tracts. 



The granite principally occupies an extended line passing 

 through the counties of Wicklow and Carlow, and is succeeded 

 in the northern portion by mica slate, resting on its eastern and 

 western sides ; but towards its southern extremity, the mica 

 slate is wanting ; and it is found in contact on the eastern side 

 with clay slate, and on the western with the floetz limestone, 

 The clay slate is found also occupying a large part of the county 

 of Waterford, and occurs again to the westward, in the counties 

 of Clare and Tipperary. 



These primary rocks are found variously stratified with each 

 other, and with trap, porphyry, and greywacke, both compact 

 and slaty. 



The portion to which the author has assigned the application 

 of transition tract, is of very limited extent, and occupies the 

 northern part of the county of Dublin, and the western part of 

 Meath. It consists of clay slate conglomerate, grey wacke, and 

 greywacke slate, interstratified with limestone, trap, and por- 

 phyry. 



The floetz tract is much more considerable, and may be 

 divided into 



The old sandstone, 



The floetz limestone, and 



The coal district. 



The old sandstone is much dispersed, and is found resting on 

 granite, clayslate, and greywacke, and occurs sometimes in 

 isolated portions, and sometimes forming mountain masses. 



The floetz limestone is the most extensive formation in Ireland. 

 With the exception of the counties of Derry, Antrim, and Wick- 

 low, there is no part of the island in which it does not more or 

 less prevail. It exhibits considerable variety of character in 

 colour, structure, and hardness, and is found both in unmixed 

 and continuous strata, as well as associated with other rocks, 



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