284 MR. T. 0. BOSWORTil OlST THE [Juue I912, 



derived only from the rock immediately at hand. There is no 

 commingling, such as occurs in gravels and beaches. On account 

 of the number and distinctiveness of the different Charnian rocks, 

 this statement is made with confidence. 



The stones are utterly unlike beach or river-pebbles. Around 

 the South Leicestershire syenites they are worn and fretted into 

 irregular ' nugget ' shapes, with surfaces pitted and smoothed (see 

 PI. XX, fig. 1). Even the very small chips are not sharp. At 

 Mountsorrel the stones, though irregular, are less ' warty.' 



At Groby, besides the worn stones, are some with very sharp 

 points and edges, as though they had been splintered off by 

 temperature changes (see PI. XX, fig. 2). At Pardon, where the 

 rocks are cleaved, the fragments are mainly angular. At Swithland 

 and Woodhouse the chips of slate mostly have blunted edges. 

 But common to all is their un weathered state. 



The stones occur as : — 



(1) Breccias and screes resting against the rock- 

 slopes or in gullies. — The finest example of a scree was seen 

 at Croft. It was from 10 to 12 feet thick, resting against a rock- 

 face sloping at 35°, and exposed in section to a height of 35 feet, 

 all beneath Keuper Marl.^ 



The scree consisted of fretted and subangular stones, and its 

 upper surface was inclined at about 28° ; while the lower beds of 

 the succeeding marls were inclined at 1-5°. 



One of the best examples of breccia in a gully is seen in the 

 Bardon Hill Quarry, where a gully on the northern face is filled 

 with angular stones to a depth of 20 feet. 



(2) Breccia and grit-beds interbedded with the marls. — 

 These are common in almost every quarry-section. Generally, the 

 thickness is less than 3 feet ; and the bed consists of fine grit, with 

 a few larger stones which rarely exceed 2 feet in diameter.'^ 



Even within the limits of a quarry-section, these beds often are 

 seen to thin away, though more commonly they pass into normal 

 grey ' skerry ' bands. 



(3) Stones in the marl. — In the marl similar large and 

 small stones occur separately, and many beds contain small particles 

 of grit in abundance. 



At Mountsorrel, stones, sometimes as large as 5 feet across, are 

 seen as much as 8 feet or more above the rock-floor, the marl 

 beneath appearing depressed, as though the stone had fallen in. 



Almost wherever the stones occur, whether in the marl or in 

 aggregates, there is associated with them a small proportion of 

 far- travelled sand consisting of quartz-grains, sometimes nearly 

 spherical, together with magnetite, zircon, and rutile (these three 



■^ See Trans. Leicester Lit. & Phil. Soc. vol. xii, pt. i (1908) fig. vii; or Geol. 

 Mag. dee. 5, vol. v (1908) pi. xvi, fig. 4. 



'^ See Greol. Mag. dec. 5, vol v (1908) pi. xv, fig. 1. 



