On Glauconite from the Greensand near Lewes, Sussex; the constitution of Glauconite

Extract

A Boring male at Iford Manor, 1½ miles S.E. of Lewes, Sussex, yieled the following section:

The lower sand contained numerous grains of glauconite, while the upper bed was black when wet and consisted almost entirely of dark-green glauconite, with a few shell fragments and large quartz grains. The glauconite grains were small and were separated in an almost pure state by sieving; the portion coarser than 76 [wires to the inch] mesh contained the shell fragments, &c., while that below was nearly all glauconite, with a few very small grains of magnetite present in the sand.