Yol. 50.] BORINGS AT CTJLFOJRD, WINKEIELD, WARE, AND CHESflUNT. 509 



The division between the Reading Beds and the Thanet Sand is 

 rather doubtful, and the depth to the Chalk is 11| feet less than 

 was given before. This is for the most part, if not altogether, 

 explained by the surface from which the above measurements were 

 made being at least 8| feet, and perhaps rather more, below the 

 original surface of the ground from which the earlier measure- 

 ments were started. 



Samples arid Section. 



We now give descriptive notes of the samples sent us by Mr. 

 Francis, including the remarks made by Mr. W. Hill on eight 

 specimens which he was kind enough to cut and examine for us. 



At 630 feet. Rather hard, whitish chalk, evidently belonging to the 

 top of the Lower Chalk. 



At 722 and 733 feet. Hard, light-grey chalk. 



At 734. Soft, grey, marly chalk. 



At 736. Firm grey chalk. 



At 746. Very hard, whitish, gritty chalk, with large scattered grains 

 of glauconite. This was sliced by Mr. Hill, who describes it as 

 very full of shell-fragments with many foraminifera and 

 calcareous spheres, and a few sponge-spicules replaced by 

 calcite. , Moreover the rock is indurated by infiltrated calcite. 

 It resembles the hard rock-bed which occurs in the Chalk Marl 

 of Risborough (Bucks), except that it contains much less quartz 

 and glauconite. 



At 750 and 754. Soft, grey, marly chalk. 



At 759 and 760. Rather hard grey chalk. That from 760 has been 

 cut, and is described as a chalk-marl with rather a large 

 quantity of even-sized shell-fragments, with here and there a 

 larger prism of Inoceramns-sheil. The quartz-grains are also 

 small. Glauconite, calcareous spheres, and foraminifera are 

 present, but not abundant. 



At 762. Soft, grey, marly chalk. 



At 763, 764, 765. Firm, grey, silty chalk. 



At 770. Soft, dark-grey chalk-marl. 



At 771. Hard grey cbalk. This was sliced, and found to be a shelly 

 chalk-marl with many grains of glauconite ; but with only a 

 very few small grains of quartz : it is practically without quartz- 

 sand. 



At 774 and 779. Mottled dark- and light-grey marls. 



At 780. Rather hard light-grey chalk. 



At 784. Grey, mottled, sandy and glauconitic marl. This consists 

 largely of quartz-sand and glauconite-grains, which are thickly 

 packed in a matrix of amorphous material, the proportion of 

 calcareous atoms not being large. We thought this might be 

 the base of the Chalk Marl, but Mr. Hill regards it as Green- 

 sand. There are no spicules or foraminifera, and very few 

 shell-fragments. 

 Q..J.G.S. No. 199. 2 m 



