Photo and Process Block by Bemrose & Sons, Limited, Derby. 



JPLATE II. 

 MICROSCOPIC SECTION showing junction' of Dioritic lamprophyre dyke, with 

 indurated Silurian shale. The lamprophyre is at the top. Intermingling'of igneous and 

 sedimentary rock below. The hornblendic bands are the darkest. The lighter parts arc 

 sedimentary, traversed by short dark bands composed of biotite (X 4|_ ) 



