324 



SECTIONAL TRANSACTIONS.— C. 



and Wales. The south-western provinces (including Devon and Cornwall and 

 Brittany) may have yielded the detrital constituents, but the coarseness, variety and 

 freshness of the heavy minerals of the Aptian of the northern Midlands and Yorkshire 

 appear to demand a source closer to hand and at present unknown to us. The 

 long-standing puzzle of the source of the Aptian deposits must therefore still be 

 regarded as unsolved. 



Afternoon. 

 Excursion to the Drifts of the Aire Valley. 



Saturday, September 3. 



Excursion to examine the Millstone Grits and Lower Coal Measure 

 Rocks of Huddersfield and Blackstone Edge. 



Sunday, September 4. 



Excursion to South-east Craven. 



Monday, September 5. 



Presidential Address by Dr. Herbert H. Thomas, F.R.S., on The 



Tertiary Plutonic Centres of Britain. (See p. 43.) 



Dr. G. W. Tyrrell and Mr. B. H. Barrett. — The New Red Sandstone 

 Rocks of Arran. 



The first complete stratigraphical succession of the New Red Sandstone of Arran 

 was established by Prof. J. W. Gregory. 1 At the same time the senior author (G. W. T.) 

 contributed a description of several critical sections ; 2 and the junior author (B. H. B.) 

 has recently described the petrographical characters of the Brodick Breccia, and has 

 traced the provenance of its constituents. 3 The present communication confirms 



Diagrammatic Section of New Red Sandstone Rocks in Arran. 



1. Corrie Sandstone ; 2. Brodick Breccia; 3. Lamlash and Machrie Sandstone; 



4. Ballymichael and Glen Dubh Sandstone ; 5. Lag a Bheith Marls and Comstones ; 



6. Auchenhew Sandstone and Shales; 7. Lsvencorroch Marls and Comstones. 



1 ' The Permian and Triassic Rocks of Arran.' Trans. Oeol. Soc. Glasqow, xv. pt. 2, 

 1914, pp. 174-87. 



Ibid. pp. 188-99. 

 The Permian Breccia of Arran.' Ibid. xvii. pt. 2, 1925, pp. 264-70. 



