The Levenshulme Limestones. 289 



Following this plant bed comes a long series of variegated 

 shales, purple at first, and becoming redder towards the 

 base. These are again followed by variegated bright purple 

 and green marls, and again a mass of purple shales with 

 dark bands, becoming red towards the base, where bright 

 hematite red clays terminate the series. The total thick- 

 ness of marls and clays between the 1st and 2nd groups of 

 limestones is thus 28' 9", or say about 30 feet. 



The occurrence of hematite iron in the Upper Coal 

 Measures is generally well marked over England, and it is 

 exemplified in this section. At several points the beds are 

 very strongly marked by hematites. It was pointed out by 

 the late Sir R. I. Murchison that the hematite ores of 

 Furness had been produced at the close of the Carboni- 

 ferous epoch, and the deposits which had then been made 

 in the fissured rocks of the coal measures and limestones had 

 been sealed in by the breccias of the Permians. It is the 

 same here in a lesser degree. We find all the strata tinged 

 with hematite, and several of the clays, which have been 

 analysed by Mr. Bone, of Owens College, yielded as much 

 as 10% of iron. All the fossils are coated red with hematite* 

 and bits of pure ore are found in many positions. The 

 section, therefore, furnishes this fresh evidence of the pre- 

 valence of hematite in the closing period of the carboni- 

 ferous epoch. 



The hematite band at this point was a very striking 

 feature in the section, and strongly impressed us with the 

 possibility of its marking the impending change of condi- 

 tions here which obtained in the North of England just 

 before the Permian conglomerates were formed. 



2nd Group of Limestones. 



The second group of limestones commences 90 feet east 

 of Slade Lane Bridge, and is a great contrast to the first 



