GLAZEBKOOK MOSS, LANCASHIRE. 809 



for there seems no other reason why the Moss should be in this 

 particular spot and absent on the boulder-clay land at the same 

 level surrounding it than the preexistence of the forest on the site 

 of the Moss. It is also probable that the Moss, commencing at a 

 nucleus of forestal decay, has pushed itself outwards, as one of the 

 first trees I tried near the edge of the Moss was an ash, very little 

 discoloured by peat and quite sound. 



This tree could not have been so long imbedded in the peat as 

 those near the centre, and may have been engulfed by the bursting 

 of the Moss. At the northern edge of the Moss stunted birches are 

 growing in it, exactly similar in the bark to those imbedded in 

 the peat. 



The Boulder-clay extends over the whole length I walked, viz. 

 six miles. 



Just south of the Liverpool and Manchester Railway there is a 

 fine section of the Boulder-clay, about 20 feet deep. It is, as com- 

 monly happens, divided by a thin seam of sand, very persistent, the 

 clay above being 12 feet deep in the thickest part, and about 4 feet 

 in the thinnest. The clay above this breaks off with a grey fracture, 

 showing a very distinctive difference from that below ; but both are 

 very free from stones. 



I attach no geological importance whatever to these distinctions : 

 the difference in the upper clay is simply produced by drainage 

 caused by the sand-seam, and fractures by shrinkage down to it. 

 These grey fractures always go to the nearest sand-seam, seldom 

 below it ; they are merely the result of deep natural subsoil drainage. 



Beyond the bridge, at 5 miles 78 chains, near Byram Lane, there 

 is a bed of laminated clay (book-leaf) in the Boulder-clay at the 

 bottom of the cutting, about 8 feet from the surface, which has been 

 penetrated 18 inches deep ; it extends about a quarter of a mile. 

 The laminations are very fine, and are nicely preserved in the lumps 

 of burned ballast made from the clay. 



About 1 mile 32 chains, near the northern edge of the Moss, a 

 boring showed 7 feet of clay and soil and 27 feet of gravel (unbot- 

 tomed). At 1 mile 55 chains another boring showed wet sand 8 feet, 

 stiff clay 6 feet, wet gravel 9 feet 6 inches, and then sandstone 

 penetrated 4 feet. At 2 miles another boring showed 6 feet dry sand, 

 11 feet gravel, 11 feet strong clay, and then sandstone. The sur- 

 face-levels were all between 60 and 65 feet above Ordnance-datum. 

 The summit-level of the Boulder- clay was 119 feet above Ordnance- 

 datum in the length I traversed, and at 4 miles 20 chains *. 



In the Boulder-clay Mr. Beloe (the engineer of the line), who 

 kindly called my attention to the section, informs me he found the 

 trunk of a tree deeply imbedded ; the spot was pointed out to me. 

 The timber was said to be oak, 6 feet long and about 14 inches 

 diameter, imbedded vertically, the lower end about 9 feet below the 

 surface, and the clay undisturbed about it. This is the first instance 

 I ever heard of timber in the marine Boulder-clay of Lancashire. If 

 genuine, it must have been drift timber. 



* All the distances given are from the j unction at Glazebrook station. 



