1868.] MAW — VARIEGATED STEATA. 305 



BufF blotches in red marl (Analysis No. 5) contained 



Sesquioxide of iron 2*779 



Protoxide of iron 1'468 



Traces of sulphur. 



The general composition of the red and buff portions of the marl 

 exhibited no material difference. 



Eed Permian marl, with buff blotches, near Bridgnorth : — 

 Eed marl (Analysis No. 21, Dr. Yoelcker) contained 

 Oxides of iron, principally sesquioxide 8'76 percent. 



Buff blotches on red Permian marl (Analysis No. 22) con- 

 tained 

 Oxides of iron, principally sesquioxide 367 per cent. 



Red Marl, Old Eed Sandstone, with buff blotches (roadside, Norley, 

 near Bridgnorth) : — 



Eed marl (Analysis No. 13) contained 



Protoxide of iron O'^Ol -.^ , „. . ^^n 



o • •-! o- n rv^ r Metallic iron 7'(X). 



Sesquioxide of iron 900/ 



Buff blotches on No. 13 (Analysis No. 14) contained 

 Protoxide of iron 0*54 



Sesquioxide of iron, probably 1 g.^^ V Metallic iron 6*44. 

 hydrous J J 



The blotching of the red beds of the Wyre Eorest Coal-field, 

 "Worcestershire (fig. 27, Plate XIY.), presents another phase of varie- 

 gation, which is of frequent occurrence, viz. the bleached portions 

 being adjacent to an overlying bed of sandstone, and branching out 

 therefrom into the general mass of the underlying marl. As the 

 disposition of the fields of colour is very suggestive of infiltration 

 from the overlying beds in contact with the bleached marl, I have 

 procured complete analyses of the red and the bleached portions. 



The composition of the claj^ railway- cutting near Bewdley, Wor- 

 cestershire (fig. 27, Plate XIY.) was determined as follows, by Dr. 

 Yoelcker. 



Analysis No. 46 (rea). No. 47 (buif). 



Water of combination 6'32 4*49 



Sesquioxide of iron 12*21 3'44 



Protoxide of iron 040 061 



Bisulphide of iron O'll 0022 



Alumina 17-57 533 



Sulphate of Kme 0-07 0*15 



Lime in a state of silicate 071 0-71 



Magnesia 2-22 073 



Potash and soda 0-56 0*24 



Insoluble silicates 60*29 84*35, including : — 



Silica 50-23 65-30 



Oxides of iron (weighed as sesquioxide) 1*19 1 -59 



Alumina 6*33 14*33 



Lime 0*71 0*52 



Magnesia 0*37 0*34 



Alkalies and loss 1*46 2*27 



100-46 100*07 



