B. If. Rastall — Minerals of Lower Greensand. 269 

 8. A Small Exposure in a Cottage Garden by the Roadside, 



ABOUT HALF A MILE WEST OF WoiSURN. 



This sample consisted of a dirty brown sand, containing much fine 

 muddy material, and very ferruginous. The larger constituents 

 showed no noteworthy features, and the heavy residue was quite 

 small in amount. All the usual minerals were observed, namely 

 kyanite, staurolite, rutile, tourmaline, and zircon, together with 

 a good deal of magnetite and brownish opaque grains. None of these 

 minerals showed any characters worthy of special description. It 

 may be mentioned that the crystals of kyanite show the worn and 

 rounded outlines usual in this district, while the staurolites also are 

 more rounded than ordinary. 



9. Leighton Hollow Wood, Woburn. 



These specimens were collected from a long section by the side of 

 the road from Woburn to Aspley Guise, and consisted of rather dirty 

 ferruginous sands, which when cleaned, panned, and separated yielded 

 some good specimens of heavy materials. As usual the chief species 

 present were zircon, kyanite, staurolite, tourmaline, and rutile. 



Zircon is very abundant as small, well-rolled grains, mostly as the 

 clear colourless variety without zones, but showing characteristic 

 inclusions. 



Tourmaline is very common, chiefly as well rounded drop-like grains 

 of an olive-green or brown colour, but other grains are distinctly 

 blue. One in particular showed a peculiarly intense and brilliant 

 blue shade, while in others the same tint is less marked. Kyanite 

 shows many good examples of the most characteristic forms, some 

 fairly sharp, while others are a good deal rounded. 



Staurolite is found in grains showing a wide range of forms : while 

 some are very angular indeed, others are unusually well rounded, and 

 many transitional types are seen. The orange-red variety of rutile is 

 the more common, sometimes in fairly large and irregular pieces, but 

 there are also a few large crystals of a deep blood-red colour. 

 Epidote is a rather rare constituent, generally in rounded green 

 grains, but occasionally in large angular pieces. Although this 

 locality is so near Aspley Guise no sphene was found, a rather 

 remarkable circumstance. 



10. Small Pit by Side of Road between Woburn and 

 Little Brickhill. 



This is a small excavation about 5 feet deep, in fine incoherent 

 yellow sand, with a few brownish streaks and patches. The sand is 

 of uniform grain, nearly all passing through a sieve of about 1 mm., 

 and there is very little fine mud on washing, hence the grains must 

 be naturally well- graded. 



A small sample, strongly heated in a crucible for some time, turned 

 to a bright brick-red colour, presumably from dehydration. Another 

 sample boiled for some time with acid and well washed showed a 

 large amount of bright-green glauconite, and also some grains, 

 similar in size and shape, but of a pale-brown colour. As this 

 seemed a favourable opportunity to investigate the nature of these 



