532 W. W. WATTS ox THE IGXE0T7S AND 



40. On the I&xeous and Associated E,oces of the Brezddex Hills in 

 East Moxtgomertshiee and "West Sheopshire. By W. W. 

 Watts, Esq., M.A., F.G S. (Eead June 24, 1835.) 



I. Literature. 



MuRCHiso:??, Sir E. I. Silurian System, p. 290, et seq. 1839. 



. Siluria, p. 89. 1859. 



MoRTO^^, Gr. H. On the Geology and Mineral Yeins of the country 



around Shelve, Shropshire, with a notice of the Breidden Hills. 



Proc. Liverpool Geol. Soc. pp. 40, 41. 1868-69. 

 Stmoxds, Prof. W. S. Records of the Eocks, p. 89. 1872. 

 Eamsat, Sir A. Geological Survey of jS". Wales, p. 328. 1881. 

 Ea^-dall. Severn YaUey, pp. 120-122. 1882. 

 La Touche, Eev. J. D. Geology of Shropshire, p. 12. 1884. 

 YnfE, G. E. Quart. Journ. Geol. Soc. xli. p. 109. 1885. 

 Geological Survey. Map. Sheet 60 N.E. 1850 and 1855. 

 . Horizontal Section. Sheet 35. 1853. 



II. IlfTRODirCTIOJf. 



The rocks described in this paper occur in a district on the borders of 

 Shropshire and Montgomeryshire, on the east side of the Severn, about 

 12 miles W. of Shrewsbury and 6 miles xf.E. of Welshpool. They 

 are mapped by the Geological Survey, but no detailed description, 

 except a few notices in Murchison's works, has yet been published. 



There are three chief parallel ridges running 'N.'E. and S.W. The 

 two westerly ones, called the Breidden or Eodney's Pillar Hill (1143') 

 — extending northwards as far as Brimford Wood — and the Criggan, 

 are composed of intrusive basic rock, and of this there are also one or 

 two other little hills, — the Garreg near Trewern and Poel Coppice to 

 the south, Belan Bank rising out of the alluvial plain of the Severn, 

 and two small hills to the north. The easterly ridge, whose chief 

 summits are Moel-y-Golfa (1199'), Middletown Hill, Bulthey Hill, 

 and Bausley Hill, consists of lavas, ashes, and conglomerates of an 

 intermediate type. Associated with these igneous rocks are shales, 

 sandstones, and mudstones, which appear to be an inlier of the 

 Bala rocks of Shelve reappearing under the Silurian s}TLclinal of 

 the Long Mountain to the S.E., which also seem to reappear as a 

 tiny inlier at Buttington, and are apparently continued further to 

 the S.W. in a strip of similar rocks to the E. and S.E. of Welsh- 

 pool. 



In this paper I propose to describe the contemporaneous and in- 

 trusive igneous rocks of the region, and to give a short account of 

 the sedimentary rocks connected with them. And here I have great 

 pleasure in expressing my most sincere thanks to Dr. Davidson and 

 Prof. Lapworth for their kindness in determining my fragmentary 

 fossils, and to Prof. Bonney and Mr. AUport for their ready help in 



