part 1] ON THE OE0L0OY OF THE OLD EADXOH DISTKICT. 3 



Iii 1850 J. E. Davis gave a list of fossils collected from the 

 limestone at Xash Scar, with the view of determining the age of 

 the limestone. 1 Of this collection Murchison remarks 



' All the fossils which have been found in the limestone of this tract, whether 

 by Mr. Edward Davis, who discovered most of them, and specially assisted me 

 in studying them, or subsequently by the Government Surveyors, are truly 

 Wenlock and Upper Silurian forms.' (' Siluria : 1st ed. 1854. p. 105.) 



Unfortunately, the present whereabouts of Mr. Davis's collection is 

 unknown, and only a very few specimens from this locality are 

 preserved in the Museum of Practical Geology, Jermyn Street. 



Since Murchison's time only one writer has dealt with the 

 Old Radnor district.- In the Quarterly Journal for 1901) 3 Charles 

 Callaway briefly described the grits and limestones of Old Radnor 

 Hill and Yat Hill, and suggested for the first time a Pre-Cambrian 

 (Longmyndian) age for the grits. He based his conclusions on 



(1) The resemblance which he traced between the Old Radnor grit and the 

 rocks of the Longmynd ; (2) the similar trend exhibited by the rocks in the 

 two districts ; and (3) an unconformity which he noticed betv.-een the lime- 

 stone and the underlying ' Caradoc r Sandstone of Murchison. 



This paper did not come to our knowledge until some time after we 

 had begun work in the district; but. although it anticipates the 

 conclusions at which we had arrived regarding the Pre-Cambrian 

 .age of the grits, we think that it may be worth while to record 

 our observations in this connexion. These observations not only 

 >eonfirm Callaway's general contention, but, as thev include the 

 discovery of several additional rock-types, they render it possible to 

 discuss more fully the particular group in the Longmyndian of 

 Shropshire, to which the Old Radnor series appears to belong. 4 



Our attention was first called to this district at the Birmingham 

 meeting of the British Association by Prof. Charles Lapworth, 

 Avho suggested that the geographical conditions which had given 

 .rise to the algal development in the Ordovician rocks of Grirvan, 

 described by one of us in the Presidential Address to Section C, 5 

 most probably existed at the same time also in Shropshire, and 

 might even have extended as far south as the borders of Radnor- 

 shire. He suggested that an investigation of the limestone in the 

 latter area might possibly reveal the presence of beds of Caradoc 

 age beneath the Wenlock rocks of the district, and that these 



"O 



1 Q. J. G. S. vol. vi (1 850) p. 437. 



2 The igneous rocks of Stanner. which are described by Prof. G. A. J. Cole. 

 Geol. Mag-, dec. 3, vol. iii (1886) p 219, are not included in the scope of 

 the present paper. 



3 ' Longmvndian Inliers at Old Radnor & Huntley ' Q. J. G. S. vol. Ivi 

 (1900) p. 511, 



4 The statement in Mr. T. C. Cantrills paper ' On a Boring- for Coal at 

 Presteign' Geol. Mag. dee. 6, vol. iv (1917) p. 490, that C. Callaway records 

 a Longmyndian conglomerate at Old Eadnor. is not correct; perhaps 

 Mr. Cantrill was unwittingly thinking of our statement to this effect wIipu 

 the present communication was read in June 1917. 



5 Rep. Brit. Assoc. (Birmingham) 1913. p. 453. 



b2 



