, 
THE PRECAMBRIAN ROCKS OF SHROPSHIRE. 643 
48. The Precamprran Rocks of Suropsnrre.—Part I. By OC. Cat- 
LAWAY, Hsq., M.A., D.Sc. Lond., F.G.S. | With Norzs on the 
Microscopie Srrucrure of some of the Rocks, by Prof. T. G. 
Bowyry, M.A., F.R.S., Sec. G.S. (Read June 11, 1879.) 
ConTENTS. 
Introduction. 
A. Physical Geography of the Wrekin and Caer Caradoc Chain. 
B. Lithological and Stratigraphical Characters of the Rocks. 
1. Lilleshall Hill. 9. The Lawley. 
2. The Hrcal. 10. Caer Caradoc. 
3. Lawrence Hill. 11. Helmeth Hill. 
4, The Wrekin. 12. Hazler Hill. 
d. Primrose Hill. 13. Hope Bowdler and Cardington 
6. The Wrockwardine mass, range. 
7. Charlton-Hill area. 14, Ragleth Hill. 
8. District between the Wrekin and | 15. Wartle-Knoll group. 
the Lawley. 16. Kington group. 
©. Evidence for Precambrian age. 
1. Stratigraphical, | 2. From included fragments. 
General Summary. 
InTRODUCTION. 
In a paper communicated to this Society on March 21st, 1877, en- 
titled “On a new Area of Upper Cambrian Rocks in South 
Shropshire’*, I intimated that certain volcanic rocks associated 
with the shale in question, which had been usually regarded as 
eruptive greenstones, were for the most part composed of bedded 
material ; but details were deferred. 
Mr. 8. Allport, in a paper “ On certain Ancient Deyitrified Pitch- 
stones and Perlites from the Lower Silurian District of Shropshire”, 
read before this Society in May 18774, announces the same con- 
clusion from entirely independent observations, devoting his atten- 
tion, however, chiefly to the chemical and microscopic side of the 
question, and arriving at the very important conclusion that these 
(so-called) Lower Silurian pitchstones and perlites are identical 
in character with the most modern volcanic rocks. 
In June 1878, I read to this Society a paper on ‘The Quartz- 
ites of Shropshire ’’$, in which I gave several sections across the 
Wrekin volcanic chain, and assumed that the bedded rocks of which 
it is mainly composed were of Precambrian age. 
Messrs. Hill and Bonney, in their second paper “On the Precar- 
boniferous rocks of Charnwood Forest” ||, infer the same conclusion 
* Quart. Journ. Geol. Soe, vol. xxxiii. p. 652. t Ibid. vol. xxxiii. p. 449. 
{ Both Mr. Allport and myself had contemporaneously announced this fact 
to the Birmingham Natural History Society, and he informs me that it was 
known to him nine years ago. 
§ Quart. Journ. Geol. Soc. vol. xxxiy. p. 754. — ‘|| Zdid. vol. xxxiy. p. 236, 
