2o6 PROCEEDINGS COTTESWOLD CLUB 191 1 



in the form of massive travertine, called " lac lunae " by the 

 early mineralogists. All this dissolution naturally encouraged 

 fissuring, and into many of the cracks the clay of the immediate- 

 ly superincumbent deposit has often found its way. On this 

 account, Mr Walford has termed the clay-bed immediately on 

 top of the Chipping-Norton Limestone, the " Rift Bed.'" 



NecByan Beds. — To Mr Walford, practically alone, are we 

 indebted for our knowledge of these beds. He gave them their 

 name ; worked out the sequence of their component layers, 

 and to no small extent, their palaeontology, at Sharp's Hill ; 

 and proceeded a considerable way towards indicating their 

 geographical extent in North Oxfordshire. As will be seen 

 shortly, they comprise a most interesting collection of dark- 

 coloured tough clays of various tints, and marls and limestones 

 — the marls sometimes ultra-limy, and the limestones often 

 considerably arenaceous ; while fossils, mostly of novel form 

 to Cotteswold workers, abound. The mutual relations of the 

 component layers of the Neaeran Beds are difficult to determine, 

 and so are their relations to the overlying Great-Oolite beds. 



Very similar deposits to these Neaeran Beds have been 

 described in the department of L'Indre, France, by MM. Coss- 

 man and Benoist.* 



H. — Local Details. — Descriptions of Sections. 



The best section in the district whereat to commence a 

 detailed investigation, is that at Sharp's Hill (3 on map), two 

 miles north-west by west of Hook-Norton Church. It has 

 been described in some detail by Mr Walford (pp. 7-15),^ and 

 is extremely instructive as demonstrating the variability of 

 the beds between the black clay (" Rift-Bed ") and the Rhyn- 

 chonella- and Ostrea-Bed. of the Great Oolite proper. 



1 Vide H. B. Woodward, " The Jurassic Rocks of Britain —The Lower Oolitic Rocks of England 

 and Wales (Yorkshire excepted)," vol. iv. (1894), p. 159. 



2 Bull. Soc. Geol. de France, sieme ser., tome xxvii. (1899), pp. 136-143 and 543-585, P's- 

 xiv. xvii. 



3 References, such as this one in brackets after Mr Walford's name refer to his pamphlet 

 " On Some New Oolitic Strata in North Oxfordshire," Buckingham, 1906. 



