266 DE. C. A. MATLET ON THE [JuUG I9I2> 



YI. LiTHOLOGrT AND FoSSILS OE THE ArdEN SaNDSTONE GeOTjP, 



AND ITS Position in the Maels. 



As will be inferred from the descriptions already given, the 

 Arden Sandstone Group is a variable deposit, as regards both 

 mineral composition and thickness. The zone never consists 

 wholly of sandstone, but always contains a considerable admixture 

 and often a great preponderance of grey shale and marl. Bands of 

 red shale and marl are also occasionally present in it. The sand- 

 stone facies is best developed in the neighbourhood of a line passing* 

 in a north-easterly direction from Alcester through the Alne Hills, 

 Henley-in- Arden, and Eowington. Occasionally, the sandstone is 

 sufficiently thick-bedded and hard to be utilized locally for building- 

 purposes and for gravestones, and it was formerly quarried for these 

 purposes at Shrewley, Eowington, and Mows Hill. Several churches 

 in Arden were built of it in mediaeval times, and the town-cross at 

 Henley-in- Arden seems to be made of it. But all the quarries are 

 disused, and the only economic use that is made of the rock at present 

 seems to be at the Alne Hills escarpment, where I found the friable 

 rock being excavated for sand. The sandstone is also a minor 

 source of water-supply for the district. 



The sandstones of the zone are nearly always white or pale grey, 

 or, when weathered, pale brown. They consist mainly of quartz- 

 grains, often mingled with white kaolinized felspar, and sometimes 

 contain mica-flakes. Small pebbles are locally abundant in one or 

 more layers of the zone, and have been observed at Shrewley, 

 Knowle, east of Tanworth, and Shelfield, and they will probably be 

 found elsewhere if looked for. The sandstone bands not infre- 

 quently exhibit current-bedding and ripple-marks, and other signs 

 of shallow-water conditions ; while the presence of animal-tracks 

 and sun-cracks testifies to the fact that the surfaces of deposition 

 were left dry from time to time. The associated marls and shales- 

 are usually more evenly bedded than the sandstone bands. I have 

 not observed pseudo-morphs of salt-crystals in the group, although 

 they occur in the Marls both above and below. 



The fossils of the Upper Keuper in this area and in the adjacent 

 districts are being systematically collected by Mr. L. J. Wills and 

 Mr. AY. Campbell Smith, and the former will, I understand, describe 

 them at an early date. Such fossils as I have myself collected have 

 been handed over to Mr. Wills. Only a brief reference to those 

 occurring in Warwickshire will, therefore, be made here, and then 

 solely with the view of considering the conditions under which the 

 beds were deposited. The fossil list compiled by Mr. A. K. Horwood 

 in the ' Sixth Report of the British Association Committee on the 

 Fauna & Flora of the British Trias ' shows that collections have 

 hitherto been made almost exclusively from Eowington and Shrewley 

 and their neighbourhood, but fossils are not rare at several other 

 localities. Estlieria mimita especially is widely distributed, and I 

 have found it at many localities, including Shrewley, Eowington, 

 Knowle, south and south-east of Tanworth-in-Arden, Morton Bagot, 



