Northumberland and Durham, 



63 



Section of the Lead-mine Strata at Arkendale in Yorkshire. 



White grit 



Coal 



Millstone grit 



Plate . 



Lime 



Plate . 



Lime 



Plate . 



Lime 



Plate . 



Flinty chert 



Plate . 



Crow chert 



Plate . 



Second Crow chert 



Crow lime 



First Soapy grit 



Coal bed 



Second Soapy grit 



Plate . 



Grit 







Fs. Ft. In. 



5 



. — 16 

 14 3 — 



5 



',1- 



— 3 — 



— 3 — 

 4 1 — 



2 4 — 



1 



1 3 — 



2 



2 



1 



1 1 — 



12 — 



11 



Carri 



ed uf 



58 1 6| 



Girdles 

 Plate . 

 Chert or Iron 

 Red beds 

 Plate . 

 Black beds 

 Plate . 

 Lime 

 Plate . 

 Main chert 

 Main lime 

 Dead grit 

 Underset chert 

 Underset lime 

 Underset grit 

 Girdle 

 Grit 



Plate . 

 Lime 



Brought up 



beds 



ft. 



Ft. 



1q. 



58 







1 







3 



2 

 2 



2 



— 



— 



3 



1 

 2 

 4 



— 



- 



- 



3 







12 



— 



— 



9 



6 

 3 



6 



2 



— 



— 



— 



- 



3 







12 

 5 

 



— 



— 







__ 



Fathoms 136 2 6 



The uppermost of the beds detailed in these sections consist of 

 sandstone and shale, and they are the first that rise from beneath 

 the coal formation. The most remarkable of the sandstones are 

 1. The slate sill, a fine grained, micaceous, slaty rock of a grey colour, 

 used as a roofing slate in many villages of Northumberland and 

 Durham. It is the uppermost bed in the section of Hely field. 



2. The freestone sills : these are fine grained sandstones frequently 

 containing vegetable impressions. 



3. Hard ferruginous fine grained sandstones called hazles by the 

 miners. The sandstone in the section of Aldstone moor, called 

 nattras gill hazle, is however coarse grained. These are sometimes 

 slaty, and occasionally bear the impressions of bivalve shells. 



4. The millstone grit; a coarse white sandstone composed of 

 small angular grains of quartz, with rounded pebbles of the same 



