A HISTORY OF DURHAM 



C. The Magnesian Limestone Region, between the last-named and 

 the sea and bounded on the south by an ill-defined line curving from a 

 little west of Darlington to the Hartlepools. Until about the middle of 

 last century this was a purely pastoral district, but now many collieries 

 have been opened out in it. 



D. The Red Region, between the Lower Tees and the Magnesian 

 Limestone Region. This is the salt district. 



TABLE OF STRATA IN DURHAM 



Period 



Formation 



Recent 



Pleistocene 

 (Drift) 



River Alluvium, Peat 



Marine Alluvium , 



Old River Drift 



Old Marine Alluvium 

 Later Glacial Deposits 



Older Glacial Deposits 



Salt-Mea- 

 sures (Trias 

 above, Up- 

 per Permian 

 below) 



Permian 



Keuper Red Sandstones and 

 Marls passing downwards in- 

 to similar Permian Sandstones, 

 etc. 



Magnesian Limestone 

 Marl Slate .... 



Yellow Sands (' Quicksands ') 



Carbonifcr- 



Silurian 



Coal Measures : down to the 

 Hutton Seam inclusive 



Coal Measures : down to the 

 Brockwell Scam inclusive 



Lower Coal Measures or Gan- 

 ni!>tcr Beds. Millstone Grit 



Bernician or Carboniferous 



Limestone Series 

 BiLsement beds (so-called) . 



Ex.ict horizon unknown (Stock- 

 dale Shales [?]) . 



Character of Material 



Mud, silt, gravel, peat : border- 

 ing streams and in hollows 

 (old lakes) 



Shingle, beach sand, blowing 

 sand, mud 



Gravel, sand, loam, clay, etc., 

 of ancient river terraces 



Raised beaches 



Gravel, sand, ' leafy ' clays, 

 cave-earth (?) 



Boulder clay, some rare thin 

 sands and gravels .... 



Mostly red rocks with deposits 

 of rock salt, gypsum, anhy- 

 drite, and thin magnesian 

 limestones towards the base 



Approximate 



thickness 



in feet 



up to 30 

 up to 50 



up to 50 

 up to 30 



up to 250 



up to 200 



Often concretionary 

 Flaggy calcareous beds with 

 fish remains 



Generally yellow but some- 

 times dark-coloured, more or 

 less incoherent, water-bear- 

 ing sandstones .... 



up to 1,200 



Sandstones, shales, coals and 

 fire-clays 



Sandstone, shales, coals and 

 fire-clays 



Sandstones, shales, few coals, 

 occasionally beds o\ 'gan- 

 nister,' sandstones, shales, 

 rare coals 



Sandstones, shales, fire-clays, a 

 few thin coals, limestones . 



Coarse breccia 



' Slate-pencil ' Shales 



up to 800 



up to 15 



(usually 3) 



up to 104 



together up 

 to 5,500 



variable 



thickness 

 unknown 



The scenery <>f these regions is as characteristic in each case as the 

 industries which each supports, and will be noted under separate heads 



