64 Morris — On Sarsen-stones. 



remains of fossil mammalia, associated with land and freshwater 

 mollusca. The sarsen-stones (of which some may be still seen lying 

 about the large chalk-pit), I have noticed during the progress of the 

 workings as occurring on the upper surface of a bed of disturbed 

 chalk, above the solid chalk, and covered by a blackish or carbo- 

 naceous clay containing freshwater shells. They are of various sizes, 

 some very large, and more or less waterworn, and may have been 

 originally derived from the boulder-clay. Their position was about 

 mid-way between the back of the present workings and the entrance 

 to the pit ; but little if any brick-earth has been worked here, and it 

 is probable that their position is equivalent to the base of the brick- 

 earth deposits in the adjacent eastern brick-fields. The northern 

 side of the great chalk quarry only exposes the eroded chalk and 

 green-coated flint bed, overlain by Thanet sands covered by false- 

 bedded sand and gravel and some brown clay. The brick-earth of 

 two of the adjacent pits is almost worked out, these pits presenting 

 only the obliquely -laminated sands and brown clays, which formerly 

 were seen to rest on the brick-earth below (sometimes, however, 

 separated by a thin bed of gravel) , from which and its subordinate 

 beds all the interesting fossil remains were obtained ; the brick-earth 

 being separated from the subjacent chalk by a bed of gravel varying 

 in thickness in different parts of the area. The position of the brick- 

 earth, with its shell-beds {Cyrena, Paludina, JJnio, etc.), is only 

 well seen now in the eastern field covered by the false bedded sands 

 above noticed, where, in the upper part of the same field, the Thanet 

 sands overlying the chalk may be observed. 



The general section of these pits may be divided into two series, 

 the lower, or fossiliferous zone, comprising the gravel and overlying 

 brick-earth, in which both the mammalian and molluscan fauna 

 occurred, and the upper or unfossiliferous zone, comprising the 

 false-bedded sands and brown clays from which to my knowledge no 

 fossil remains have been obtained. 



Whether both these appearances are mainly due to the same 

 agency, that of river action, may be considered doubtful. That the 

 formation of the lower zone is evidently so, is proved by the nature 

 of the remains embedded in it, while the false-bedded character of 

 the upper sands affords evidence of a constant change, not only in 

 the direction of the currents, but in the nature of the material 

 deposited and the absence of any organic remains. The uppermost 

 bed is again different, and may have been the result of other agencies 

 than those which formed the preceding subjacent strata. Generally 

 speaking, the deposit at Grays may be mainly due to the action of a 

 river flowing through a valley, which it has partly excavated, in the 

 lower tertiary and upper chalk beds, and most probably posterior to 

 the boulder-clay period. 



Note.— A paper by Lieut, -Col. "W. T. Nicolls, entitled " Eemarks on some 

 * Sarsens ' or Erratic Blocks of Stone, found in the Gravel in the neighbourhood of 

 Southampton, Hampshire" (with a plate), appeared in the Geological Magazine, 

 for July, 1866. Vol III., p. 29Q.—Edit. 



