272 Mr. Farey's Statement of Geological Facts 



Neaghj.and perhaps much further. The northern edge or 

 end of this great Marl stratum seems submerged in the 

 ocean from Ballycastle to Lough Foyle, or near it, rising 

 towards (and producing as I expect) the mountains in the 

 north-eastern pans of Donegall ; as its western side do 

 those of the wesfern parts of Derry, Tyrone, and those of 

 Monaghan and Louth Counties too, perhaps, in so many 

 *' Hltlc systems," as the tracts of different Rocks therein 

 may not improperly be styled (in the language of Dr. R.), 

 when compared with the entire mass of the stratum 1 am 

 describing: whose eastern side seems to produce the moun- 

 tain, on the eastern side of Down County ; but wiih respect 

 to all which, I am left to much conjecture, owing to the 

 works I have read containing only the mention of Scliistus 

 or Slate (belonging to this stratum) on the western side of 

 the trough*, by Dr. R. in your 33rd vol. pages 195, 199, 

 204, &c. and App. 34, &c. : except a few facts relaiing to 

 the County of Down, which will appear in their more pro- 

 per places hereafter. With respect to the eastern side and 

 the top part of the edge of this great and lowest known 

 stratum of this district, as far as they appear within the 

 county of Antrim, though the space is vastly smaller, my 

 materials are more ample, and which I shall proceed briefly 

 to mention, requesting a careful comparison of them with 

 niy Derbyshire Report, but more so with the phsenomena 

 of the Red Marl stratum itself, that are there detailed. The 

 substances then of this district are : 



Red Marl or Clay, with its usual characteristic streaks and 

 beds of 5i;''eepi>h blue orblue marl-like Earth, which appears 

 (at Cave~ bii') at the top of this stratum, Mr. D. p 69 and 72, 

 (a thm bilumous schist, Dr. D. pref. viii.) ; Red Clay from 

 40 to 106 feet deep and more, beneath Belfast Town, 

 p. 558; in places along the vale of the Lagan and coasts 

 of Rtlfist r'ay and the Ocean, to the Island Magee, as at 

 Maheramesk N of Hillsborough, Maheragall, Belfast, 

 and CuTickierrus, Mr. D. p. 74, the Forth vale near Bel- 

 fast, and Castlechichester in Magee isle, p. 72; in the 

 Forth and Woodburn valleys (" extensive beds of Clay, 

 commonly red, so!netin)es of a deep blue and spotted,") 

 and on the shores of Carnckfergus, where it makes Bricks, 

 Dr. D. pref. vii. ; and MarleyClay at Killroot, Mr. D. 

 p. 139, &c. 



Gi/psion in the Marl or red Clay, white, yellow, reddish, 



♦ Unless the red and jrreenish Marl observed b;/ Mr. Sampson were in 

 Dsrrv, as iniglit be i.iferredj from bis being tlie surveyor of that County, 

 ineiuioned by Mr. D. p. Ci>, 



and 



