Geology of England and Wales,^^ 8fc. 221 



Red Marie, or JVea? Red Sandstone, or Red Rock, or Red 

 Ground. 



This formation comprehends the variegated sandstone of 

 Werner, and is described as "a series of marly and sandy 

 beds intermixed with conglomerates derived from older 

 rocks containing gypsum and rock salt and in one instance 

 amygdaloidal trap." The red marie, containing gypsum, 

 usually lies highest, the sandstone in the middle, and the 

 conglomerate lowest. These beds are argillaceous, and 

 argillo-siliceous, with a variable proportion of calcareous 

 matter. The colours of the marie and sandstone are of a 

 red chocolate and salmon colour; exhibiting streaks of 

 light blue, or verdigris, or bulF, or cream colour. 



"Some of the sandstone beds of this formation bear so 

 near a resemblance to some of the grits associated with the 

 coal formation, and to the softer strata of the old red sand- 

 stone underlying the mountain limestone, that a cursory ob- 

 servation of them would often lead to fallacious conclu- 

 sions. It may however be generally recognized without 

 much difficulty by the following distinctive characters ; 1st, 

 its containing gypsum ; 2ndly, by the inferior consolidation 

 of its stony beds ; 3dly, by the regularity of its stratification, 

 and the general parallelism of its beds to the horizon." pp. 

 280 and 281. 



Many other distinctive characters of this formation are 

 given ; but we have not room to quote them. It is highly 

 interesting, not for its organic remains, for it contains none; 

 but because it includes the great rock salt formation of 

 England, and also extensive beds of gypsum. The latter is 

 not wrought extensively; but (he former is dug at North- 

 wich and Droitwich. At the latter place, it exists in two 

 beds, not less than sixty feet in thickness. These are sup- 

 posed to form a large insulated mass of this mineral, about 

 a mile and an half long, and 1300 yards in breadth. 



The subordinate conglomerate of this formation has an 

 argillo-ferruginous cement and embraces rounded and an- 

 gular masses of granite, calcareous spar^ feldspar, .chert, 

 greywacke, yellowish limestone, porphyry, pieces of a com- 

 pound porphyritic rock, and steatite. 



The amygdaloidal trap, occurring in the same connec- 

 tion, sometimes covers, and at other times is covered, by-^ 

 the sandstone. Its base may be hornblende, augite. bron- 



