RAVENHEAD COLLECTION IN THE BROWN FREE LIBRARY AND MUSEUM. 397 



Rushy Park Coal, which is about 200 feet below the lowest beds visible. Plant remains 

 are numerous in the shales, and on one side of the quarry two upright trunks of trees 

 are exposed. 



In the Middle Coal Measures there are a few species of Mollusca, — Anthrocosia 

 robusta being the most common ; they usually occur in thick bands and extend a con- 

 siderable distance from one coal pit to another, particularly a band above and another 

 below the Rushy Park Coal. Fish remains also occur in many localities, but direct 

 search has not been made for them, though there is little doubt that the scales and teeth 

 of small species would be found of common occurrence, and those of Ccelacanthus, 

 Gyrolepis, and Platysomus have been already recorded from several localities. 



Upper Coal Measures. 



These consist of red and purple shales, clays, and sandstones when seen within 200 

 or 300 feet from the surface, probably coloured by the infiltration of ferruginous water 

 from the overlying Permian or Trias, but of black shales and grey sandstones where 

 brought up during borings and the sinking of shafts. The first exposure is in the 

 cutting of the Liverpool and Manchester Eailway, between Rainhill and Marshall's Cross 

 stations, and the strata are principally of a red colour. They may occasionally be seen 

 in small openings about the reservoirs south of St Helens, but as there are no coal 



Dip 10 



2" Strong brown stone. 



Soft crumbly metal. 

 W 



Fig. 3. — Permian or Trias on Coal Measures, Haydock. (Scale, 1 inch to 6 feet.) 



seams of sufficient thickness to be worth working, and the strata of little economic 

 importance, they are seldom exposed. At Collin's Green and Bold, shafts have been 

 sunk through the base of the Trias and the whole of the Upper Coal Measures into the 

 Middle Coal Measures beneath, and both have afforded accurate sections and proved the 

 thickness of the strata at these two places, which are about a mile apart. Mr A. 

 Strahan, in the Geology of Prescot (2nd edition), gives the details of each section, 

 and the debris from the shafts still remains on the surface. The strata consist of 

 various shales and sandstones, with a red stain for some distance below the surface, but 

 as the depth increases they gradually present the usual black and grey coloured shales, 

 In both the Collin's Green and Bold sections there are numerous thin beds of coal, 

 varying from 1 to 24 inches in thickness. A shaft was sunk at Haydock a few 



