Geology. 219 



colour, generally occupying the low-lying grounds, and afford- 

 ing fine subsoil for meadow and orchard lands; containing 

 here and there veins of gypsum and celestine, but singularly 

 destitute of fossils, and chiefly interesting as ground suitable 

 for trial shafts to be sunk for the coal beneath. The estimated 

 thickness north of the Mendips, is about 200 ft. ; whilst to 

 the south of these hills it is proved to be as much as 800 ft. 

 Immediately succeeding these marls, and form- 



Rhicticbeds. . , . . , , 



mg the transition between them and the strata 

 above, come those beds wherein our late distinguished geolo- 

 gist, Charles Moore, won his geological spurs ; beds, in the 

 investigation and working out of which he so lovingly toiled, 

 and which have made our district so well and widely known— 

 i.e., the Rhaetic beds. The upper portion of the new 

 Red Marls so insensibly graduate into these that it is 

 very difficult to define accurately where one formation 

 ends and the other begins. One fact is, however, certain, 

 that a marked change in colour takes place from the red and 

 green variegated Marls of the Keuper to dark grey or bluish 

 Sandstones or Marlstones, and black shales and Limestones. 

 There is also a great accession of organic life ; for whereas 

 the beds below are singularly destitute of any remains of the 

 life of the period, those immediately succeeding are crowded 

 with fossil remains of Mollusca, reptiles, fish, and with traces 

 even of the higher Mammalia — the as yet earliest known for- 

 mation in which these occur. The name Rhsetic was given to 

 this formation by Charles Moore, who was the first to correlate 

 them with certain beds in Austrian Tyrol and the Rhsetian 

 Alps, which are of great thickness, and contain a similar/aa«a. 

 We prefer to retain this name in our locality, though some 

 geologists call them " Penarth beds," from the fact that these 

 strata are so well developed in the headland of Penarth, near 



