72 



PROCEEDINGS 



OF 



THE GEOLOGICAL SOCIETY. 



POSTPONED PAPER. 



tlie Geological Sirttctuee of ilie Malvebn Hills and adjacent 

 DisTEicTS. By Haevet B. Holl, M.D., F.G.S. 



[Read June 8, 1864*.] 

 Contents. 



I. Introduction. 

 II. Metamorphic Rocks. 



1. Keys-end Hill. 



2. Ragged- stone Hill. 



3. Midsummer Ilill. 



4. Swinyards Hill. 



5. Herefordshire Beacon. 



6. Between the Wind's Point and 



theWych. 



7. North of the Wych. 



8. General considerations. 

 III. Upper Cambrian Rocks. 



1. HoUybush Sandstone. 



2. Black Shales. 



3. Dietyonema-shales. 



4. Altered Rocks on the East of 



the Herefordsliire Beacon. 

 IV. Upper Silurian Rocks : May Hdl 

 Sandstone, or Upper Llandovery 

 Rocks. 

 V. Faults. 

 VI. Conclusion. 



VII. Description of the New Fossils of 

 the HoUybush Sandstone and 

 Black Shale. 



I. Inteoditctiok. 



In a short communication which, was read at the last meeting of 

 the British Association (1863), " On the Geology of the Malvern 

 Hills," I expressed my belief that the rocks which had hitherto 

 been treated of as syenite, and supposed to form the axis of the 

 hills, were in reality of metamorphic origin, and belonged to the 

 Pre-Cambrian, Azoic, or Laurentian age t. 



* For the other communications read at this Evening-meeting, see Quart. 

 Journ. Geol. Soc. ■vol. xx. p. 396. 



t Excluding the Hm^onian rocks, which are now believed to belong to a more 

 recent age, the Azoic rocks of the American geologists include the Laurentian 

 gneiss of Sir W. Logan, and are equivalent to the Pre-Cambrian rocks of Prof. 

 Jukes. They are, therefore, synonymous terms, employed to designate all those 

 metamorphic rocks which are known to be older than the Cambrian system. By 

 whatever name they may be distinguished, however, they are parts of the old 

 Pre-Cambrian continents, of which the metamorphic rocks noi'th of the River St. 

 Lawrence, of the Hebrides, the Malverns, Scandinavia, Bohemia, Brittany (?), 

 &c., and probably of Charnwood Forest and Donegal, &c., are uncovered areas. In 

 the absence of organic remains, and in the insufficiency of mineral characters, 

 we have no means of correlating the local subdivision of these very ancient rocks ; 

 we must, therefore, be content to take them as a whole. 



