Geological Society. 57 



GEOLOGICAL SOCIETY. 



May 19. — A paper entitled " Notes on the Geological Po- 

 sition of some of the Rocks of the N.E. of Ireland;" by Lieut. 

 Portlock, R.E. F.G.S. was read. 



In this paper the author alludes to the communications on 

 the same subject by Dr. Berger, Dr. Buckland, and the Rev. 

 W. Conybeare, published in the Geological Transactions. — 

 And after some remarks on the granite and mica-slate rocks 

 of the Mourne Mountains, the Carlingford, and another group 

 occupying a large portion of the north of Derry (the barome- 

 trical measurement of which, is given), he proceeds to notice the 

 phaenomena of the basaltic range, and to observe the con- 

 nexion of the indurated chalk with the basalt ; beginning at the 

 south near Belfast, where it is underlying and almost in con- 

 tact with the basalt of Mount Divis, tracing it at various points 

 northwards to Ben Evanagh, and high up in Benbradda, and 

 describing the gypsiferous marl, having the same dip (30° 

 N.W.) and line of direction as the chalk, next to which and 

 between it and the basalt, there is generally a thin stratum of 

 ochre. To the south of the line of chalk and resting on the 

 Dromore porphyry, a highly indurated argillaceo-iiliceous 

 schist is found, passing by various shades into a clay-stone por- 

 phyry, being, however, in its simple state, harder than the basis 

 of the porphyry. 



The author concludes, by giving his opinion that the den- 

 sity and crystallized structure of basalt, is not affected by the 

 amount of pressure ; and stating that he has not been able to 

 make out any decided proof of the stratification of that rock. 



June 2. — A paper entitled " On the fresh-water strata of 

 Hordwell, Beacon and Barton Cliffs, Hants ;" by C. Lyell, 

 Esq. F.G.S. was read. 



The author, after confirming Mr. Webster's discovery of 

 a distinct fresh-water formation on the Hampshire coast, cor- 

 responding with the lower fresh-water formation in the Isle of 

 Wight, states that in consequence of the suspicions entertained 

 of the possible occurrence of the upper marine formation in 

 some of the upper strata of Hordwell Cliffs, he has examined ' 

 the beds; a minute detail of which, in their order of super- 

 position, together with the organic remains peculiar to each, 

 is given. Bituminized wood, seeds and capsules of plants 

 (among them Carpolithes thalictroid.es Brongn.) with fresh- 

 water shells abound therein : and, in a bed of calcareous marl 

 sometimes slightly indurated, from 6 to 8 inches thick, and 

 consisting of an aggregate of Planorbes and Lymncece, an 

 abundance of gyrogonites (Chara medicagimda) was found. 



Vol. 68. No. 3S9. July 1826. H In 



