286 Reports & Proceedings—Liverpool Geological Society. 
interesting results. These beds lie flat on vertical Devonian, 
Silurian, Ordovician, or Cambrian, and the included pebbles are 
recognizable fragments of the underlying rocks. Dr. Bagg considers 
the cherts to be Cambrian or Ordovician, and has identified 
seventeen genera and forty-five species of Foraminifera, many 
Sponges, some Radiolaria, Bryozoa, etc. The Foraminifera 
are uncrushed, present perfect outlines, and reveal many genera 
(as Virgatina and Bolivina) usually associated with more recent 
deposits. The paper is illustrated with four plates, and the carefully 
drawn figures of the sectioned specimens are placed side by side 
with the recent form. Altogether an important and interesting 
communication, invoiving a great deal of study and knowledge. 
REPORTS AND PROCEEDINGS. 
LIVERPOOL GEOLOGICAL SOCIETY. 
12th April, 1921—W. T. Walker, Esq., B.Sc., F.G.S., President, in 
the Chair. 
The following paper was read: “ On certain Mineral Deposits in 
Stratified Rocks, with special reference to the Carboniferous and 
Trias.” By H. W. Greenwood, F.G.8. 
The mineral deposits dealt with included the lead and zinc deposits 
of the Carboniferous limestones of Somerset, North Wales, Derby- 
shire, Northumberland, and Cumberland, the copper deposits of 
Alderley Edge, Cheshire, and of Ecton, and the hematite deposits of 
North and South Wales, Lancashire, and Cumberland, all of which 
were considered to possess common characteristics summarized as 
follows, viz. :— 
(1) The deposits are all younger than the rocks in which they 
occur, they all show definite signs of having been deposited at a 
period later than the major earth-movements of the areas in which 
they are found, and also later than the major denudation of the 
particular districts. 
(2) Their component minerals have all reached their present 
position by a process of solution and percolation, and have obviously 
been derived from above and not from below, in which they are in 
marked contrast to magmatic ore bodies. 
(3) They generally take the form of filling of joints, cracks, faults, 
solution fissures, and are often metasomatic replacements. 
A detailed description of the various deposits was given, and 
evidence adduced. to prove that the lead and zinc ores were certainly 
of post-Triassic age in the Mendip area, and of much later date in the 
other areas. In practically every area they occur at altitudes over 
500 feet above sea-level, i.e. in areas of comparatively high relief. 
The hematite deposits on the contrary occur at relatively low levels, 
