152 



CHAPTEE XL 



NEW RED SANDSTONE AND MARL, AND RH^TIC BEDS. 



THE NEW KED SANDSTONE SERIES, or TRIAS, succeeds 

 the Permian strata. It has received the name of Trias 

 from the fact that when fully developed, as in Germany, 

 it consists of the three great divisions of Keuper marls, 

 Muschelkalk, and Bunter Sandstein. Comparatively 

 few genera and no species of bivalve shells pass thus far 

 upwards. The majority of the old genera of Brachiopoda 

 disappear, and the whole grouping of the fossils now 

 ceases to be Palaeozoic, and assumes a character com- 

 mon to the Mesozoic or Secondary strata. The British 

 section, with the exception of the Muschelkalk, is as 

 follows : 



-Red marl and thin bands of white sandstone, with 

 Keuper < Rock-salt. 



I White sandstone and red marl. 

 (Muschelkalk absent in Britain). 



f Soft red sandstone. 

 Bunter < Quartz conglomerate. 



I Soft red sandstone. 



These beds, with variations, occupy the undulating 

 lands from Devonshire along the banks of the Severn, 

 round the eastern borders of the Palaeozoic rocks of 

 Herefordshire and North Wales. From thence they 

 stretch eastward to the Permian and Carboniferous 

 rocks of Lancashire, North Staffordshire, and Derby- 



