192 PROF. T. T. GROOM ON THE GEOLOGICAL [Feb. I9OO, 



of angular fragments of Archaean and Triassic rocks. The fault itself 

 was apparently seen by Phillips on the eastern side of some portion 

 of the Malvern Range, where it dipped 60° eastward. 1 At Malvern 

 Link the faulted surface of the Archaean massif, with its covering 

 of breccia, is admirably shown. The fault here displays its cha- 

 racteristic sinuous course, and dips north-eastward at 65° to 75°, 

 usually between 65° and 70°. It is, therefore, a normal fault. 



The throw of the fault was reckoned by Strickland at about 

 2i miles. 2 13ut in this estimate no account was taken of the 

 unconformity at the base of the Haffield Breccia, although this 

 had been previously described by Phillips (op. cit. p. 112). Ac- 

 cordingly a great thickness of Carboniferous, Old Red Sandstone, 

 and Silurian has to be deducted. The throw may be estimated 

 by comparing the position of the Trias and Permian at adjacent 

 points on the two sides of the fault, the thickness of the Haffield 

 Breccia and of the various members of the Trias being estimated 

 with the aid of fig. 30 (p. 188), which is based on the known thick- 

 ness of the rocks concerned. In my opinion this method will give 

 fair approximations to the truth. Calculations made in this way 

 indicate that the throw varies from less than 200 feet at the southern 

 end of the Malverns to about 1000 feet at Woodbury Hill. 



A remarkable feature of this fault is the curious way in which it 

 tends to follow a line parallel to the western margin of the old 

 mountain-chain ; it repeats in a striking manner the sinuosities of 

 the latter. This appears to indicate either a connexion between 

 the post-Liassic faulting and earlier movements, or a mechanical 

 relation between the former and the disposition of the component 

 rocks of the range. 



In addition to the main fault, other post-Liassic faults have affected 

 the area : among these are the transverse faults near Knight wick 

 Station. A transverse dislocation of the main fault has followed 

 the old fault-line running down the Gullet Pass. 3 Such dislocations 

 of the eastern fault may be only apparent, the latter haviDg perhaps 

 had from the first a zigzag course. Many small faults traverse the 

 Trias and various parts of the Malvern and Abberley district, and 

 possibly some of the faults which affect the Cambrian and Silurian 

 west of the hills may be of post-Liassic age. 



From the foregoing considerations I conclude that :— 



(1) The 'Permian' (Haffield Breccia) and Trias were not de- 



posited against a shore-line formed by the Malvern and 

 Abberley Ranges, which do not appear to have had, during 

 the period of this deposition, an existence independent of the 

 tract to the east. 



(2) The Haffield Breccia and Upper Bunter Sandstone together 



passed over much, if not the whole, of the two Ranges. 



1 Mem. Geol. Surv. vol. ii (1848) pt. i, p. 140. 



2 Phil. Mag. ser. 4. vol. ii (1851) p. 363. 



3 ^fuart. Juurn. Geol. Soc. vol. Iv ^1899) p. 148. 



