Vol. 51.] PEOF. T. G. BONNEY ON THE NAEBOEOT7GH DISTEICT. 33 



grey colour ; it became perhaps a little redder in the upper part at 

 Enderby, and more distinctly so throughout at the Narborough pit. 

 But it was evident that, as a rule, the materials had been derived 

 from a distance, probably from the argillaceous rocks of the Jurassic 

 system. 1 The ' boulders,' generally, are rather small. 2 I saw but 

 few Cin situ) that reached 1 foot in diameter, the great majority 

 measuring less than 5 inches across. Among them the syenite did 

 not appear to be common. Chalk is the most abundant rock, very 

 often in subangular to rounded pebbles, not seldom varying ' from 

 the size of a hen's egg to that of a duck's egg,' others being smaller. 

 After careful examination I became convinced that, though they 

 were frequently striated, the forms of many could not be due to the 

 action of ice, but that they must be true pebbles, either from a beach 

 or from the bed of a rather rapid stream (probably the former). 

 Flints, generally more angular, were also common. Fragments of 

 Jurassic rocks, also less worn than the Chalk, and occasionally 10 

 or 11 inches across, were fairly abundant. Among them were 

 pieces of Lias (with Gryphcea incurva), of limestone (both from that 

 formation and possibly from the ' Lincolnshire Limestone '), and small 

 septaria. I found pebbles of quartz and quartzite, probably from the 

 Bunter, and of that very hard sandstone — almost quartzite, so com- 

 mon in the more northern drifts, which I am told comes from the 

 Lower Coal Measures ; and a piece of crinoidal chert (Carboniferous). 

 These are all the rocks which I certainly identified, but my time was 

 rather limited and in some cases a close examination of the sections 

 was not possible, 3 so the list doubtless is far from being a complete 

 one. The chalk and flint probably come from Yorkshire or Lincoln- 

 shire. 4 The most westerly extension of Chalk in the former county 

 is rather more than 110 miles away, in a direction about 12° E. 

 of N. ; in the latter the southern end of the Wolds (roughly to the 

 N.E.) is almost 70 miles away, while the shortest distance to the 

 Chalk in any direction (roughly to the S.E.) is nearly 50 miles. 

 The presence of rather abundant pebbles, probably from a beach, at 

 heights of from 280 to about 350 feet above the sea, 5 is difficult to 



1 The extreme edge of the Lias is between 3 and 4 miles east or east-south- 

 east of the patches described. This is the nearest approach of Jurassic rock. 



2 They seem to run rather larger in the upper 6 feet of the clay at Croft 

 Hill than in the lower part. 



3 As at the Croft and Narborough pits ; but, on the other hand, the embank- 

 ment of a new railway crossing the road between these places was made of 

 Boulder Clay. 



* The main object of my visit last September was to see whether I could 

 recognize pebbles from the Chalk of the Flainborough district (which I had 

 examined a few months previously). I can now say that the chalk is not from 

 the northern part of Yorkshire. 



6 The height of the Boulder Clay, so far as I can make out from the 6-inch 

 Ordnance map, is approximatively as follows : — Pit W. of Nar borough, 230 feet ; 

 Croft Hill Quarry, 280 feet ; at Enderby, not much less than 350 feet. The 

 Sapcote-Stanton massif varies from about 250 to well over 300 feet (the churches 

 of the two villages are each at 310 feet), so there also glacial deposits must be 

 nearly at 300 feet above Ordnance datum. The bed of the Soar at Narborough 

 is a few feet above the 200-foot contour-line. 



Q. J. G. S. No. 201. d 



