593 



mountain side. Siliceous globules are formed by a hot spring in the 

 little capital of Usk. 



Thermal and Mineral Springs occur near Usk. 



In conclusion the author says, that the ravines through which the 

 rivers Talar and Heraz flow, are not due to denudation, but to rents ; 

 and that though the ravines are narrow, it would be difficult to point 

 out a spot, where the strata on the opposite sides correspond. He 

 noticed along the course of the Heraz, numerous eff'ects of violent 

 modem earthquakes. 



A paper was next read entitled " Notes on the Geology of the line 

 of the proposed Birmingham and Gloucester Railway," by Mr. 

 Frederick Burr. 



The author of this communication was employed on the survey for 

 the railway, and the following is a general summary of his observa- 

 tions : — 



For the first 26 miles, or from Gloucester to within three miles of 

 Worcester, the road passes over the lower lias shale, and for the re- 

 mainder of the distance over red marl and red sandstone. The lias 

 tract is generally flat, seldom exceeding 100 feet above the level of 

 the sea ; but the red marl and sandstone rise considerably higher, 

 and in that portion of the Lickey range intersected by the line of 

 railway, the sandstone attains a height of about 600 feet above the 

 same level. From the Lickey to Birmingham, the country forms an 

 undulating table land, having a mean elevation of from 200 to 300 

 feet. The author gives numerous bore hole or shaft sections, made 

 during the survey, and is thus enabled to show the nature of the 

 formations in a district, otherwise concealed by its physical features 

 or cultivated surface. 



Lias. — The lias strata belong solely to the lower shales, and consist 

 of bluish or blackish slaty clay, containing thin beds of argillaceous 

 limestone. Near the junction with the red marl, there is generally 

 a thick deposit of whitish or yellowish clay, with numerous beds of 

 rubbly limestone, usually blackish. Beds of a light colour, resem- 

 bling lithographic stone, are exposed in quarries near the Plough, 

 halfway between Gloucester and Cheltenham, and white lias is stated 

 to occur at the junction with the red marl near Crawl, four miles 

 N.E. of Worcester. The junction of the red marl is also exhibited 

 in numerous small quarries in the same neighbourhood, but the 

 strata consist of the above-mentioned whitish or yellowish clay, and 

 dark limestone. These junction beds are also exposed at Dunhamp- 

 stead, three miles S.E. of Droitwich. 



Red Marl and Sandstone. — No diff^erence was noticed in this for- 

 mation from the characters already published. The marl is gene- 

 rally red and brown, but it is occasionally variegated or streaked 

 white, and sometimes it contains a thin bed of red sandstone. The 

 following section is given of the Droitwich brine pits. Red marl, 

 with much water, 40 feet ; marl with gypsum, but no water, from 

 100 to 130 feet in diff'erent pits : rock salt, not penetrated through 

 at the depth of 170 feet. A pit at the chemical and salt works at 



3 B 2 



