30 



SALIFEROUS MARLS AND SANDSTONE. 



Is 



Throughout its range in Gloucestershire and Worcestershire, the red marl is never 

 inclined at a greater angle than 15°, the average dip of the strata rarely exceeding 

 5° to 8°, and always to the east, or a little north or south of that point. The salt 

 springs at Droitwich, and the numerous saline waters which rise to the surface upon 

 the edges of the Lias, extending thence to Gloucester, have all their source in the same 

 formation. These brine springs and the surrounding strata, were first described by 



pointing out at the same time the rocks in Germany and France which I conceived to be the equivalents of the 

 other British secondary formations. (See Geol. Proc, vol. i. p. 353, with references to the works of Alberti, 

 Hoffmann, Jager, &c.) 



Section of the Keuper descending from the village of Degerloch to Stuttgard. 

 ' 1. Rusty brown and bluish marls with sandy stone bands, shells appearing in the lower part . 10 to 12 



2. Lias limestone having a compact ferruginous exterior, and a blue interior, with many of the 

 fossils of our Lias, and much resembling some beds in the Hebrides, as well as the lower 

 claystones of Gloucestershire. Beds, nine inches thick, quarried for flagstones 9 to 10 



3. Marls and white gritty sandstone, passage into Keuper (similar to the passage described in 

 this work) 10 to 12 



r 4. Purple and green argillaceous marl with some hard, flaglike, slaty, micaceous sandstone . . 60 to 80 



5. White quartzose grits, used as millstones, with green spots of marl (Thon-g alien), weathering 

 reddish, but white on fracture ; containing large stems of plants, some of which preserve 

 their carbonaceous coating. (These beds are apparently in the place of the Ripple sand- 

 stone described in the text.) 1 6 to 20 



6. Keuper marl, like No. 4, but differing in containing subordinate thin beds of sandstone and 

 a millstone-grit, into which the marly layers pass horizontally 80 to 100 



7. Marls with bands of compact green marlstone (like that of Burghill, Luneville and Coburg), 

 passing into compactish limestone, with veins of sulphate of barytes and carbonate of lime. 60 to 70 



8. Thinly laminated, shivery marls, 20 to 30 and 40 bands exposed in one section (thickness 

 unknown) . 



The Muschelkalk limestone, which is wanting in the English New Red System, lies below the above-mentioned 

 strata, and is seen on the banks of the river Neckar. The prevailing colours of the marls and sandstones at 

 Stuttgard are purple and chocolate ; while at Coburg the principal masses are hard calcareous grits of lively 

 green colours, and at Niirnberg, the edifices of which city are built of Keuper, the rock is a pale red sandstone. 

 Among the plants of the Keuper figured by Dr. Jager and M. Adolphe Brongniart, are Equisetum columnar e, 

 Brong., Catamites arenaceus, Brong., Calamites arenaceus minor, Jager, Lycopodiolithes phlegmaroides, Sternberg 

 (Lycopodites of Brong.). See figures of other plants in this formation at Coburg in a work by Dr. Berger (Die 

 Versteinerungen der Coburger Gegend, 1832). The shells consist of Posidonia Keuperi, Voltz, P. minuta 

 Alberti, Saxicava Blainvillii, and other casts of undescribed species. In the lower beds some of the Muschelkalk 

 fossils appear, such as, Lima lineata, Avicula socialis, Schloth., Avicula subcostata, A. lineata, and Perna vetusta, 

 Goldf. Fishes occur in the formation, and they have been distinctly separated by Agassiz from those of the Lias. 

 He remarks that "this is the most recent deposit in which the fishes of the family of Ganoids have the vertebral 

 column prolonged into an unequal lobe, reaching to the extremity of the caudal fin." But the most remarkable 

 remains are the Saurians, named by Dr. Jager, Phytosaurus cylindricodon, and P. cubicodon. Some of the 

 organic remains of this formation indicate a transition downwards from the base of the oolitic system, and one 

 or two of the plants common to the Keuper and Lower Oolite are identical ; for example, the Equisetum colum- 

 nare, Brongn. Oncylogonatum carbonarium, Konig, Geol. Trans., vol. ii. p. 300, so abundant in the coal of the 

 oolite at Brora, is equally common in the Keuper of Germany. In the grand duchy of Baden, where the same 

 plant is abundantly found in schist of the Keuper formation, coal is also associated ; a fact which rests on the 

 authority of that excellent observer M. Voltz of Strasburg. (See other observations on the contents of the 

 Keuper formation, and its separation from the Gres bigarre, p. 36, et seq.) 



