Inverted Mass of Up'}.)er Cretaceous Strata. 101 



considerable measure to the stresses and disturbances set up by the 

 weight of the overlying transported mass. 



An isolated lenticular portion of this crushed floor, distinguished 

 as Di in our illustration, shows only one aspect of the manner in 

 which the bed occurs. The stratum is sometimes continuous for 

 a distance of several yards, occupying most of the space between 

 the " silver-sands " and the inverted Gault above. It then shows 

 the closest resemblance to its normal development, as seen, for 

 instance, at Garside's Pit or at Miletree Farm. Frequently, however, 

 softer portions of the bed dwindle laterally into streaks, and the 

 relations of the deposit to the underlying sand, F, show here and 

 there considerable confusion. It is possible that at the time of the 

 transgression the sandy floor may have become locally churned 

 up and its materials redeposited in close association with the other 

 constituents of bed Di ; but the later addition of the great weight 

 of the superincumbent transported mass of strata, even leaving out 

 of account the added pressure of glacial ice, seems to us to explain 

 sufficiently most of the irregularities in these relatively soft strata. 

 Some of the surfaces now marked by the presence of secondary 

 limonite-segregations, as in the upper part of bed F, doubtless 

 originated by minor disruptions caused at the same time. 



Little need be added regarding the lithological characters of bed 

 D^. These are variable, just as at the other localities where this 

 basement-bed occurs. In places the coarser constituents, that is 

 to say the rounded pebbles and grit-grains, the angular or sub- 

 angular platy fragments of ironstone, and the polished hollow 

 pebbles of ironstone, are segregated so that such portions of the rock 

 almost form a breccia. Other parts show a finer and more even 

 composition, so that the yellowish and brown sandy or gritty 

 clay-matrix then contains few of the ironstone-fragments. Small 

 pockets of greenish and brownish clay also occur. We have already 

 noted the presence in one place of a flat claystone nodule similar 

 to those forming a layer in the passage-bed (of tardefurcata horizon) 

 north of Miletree Farm. A few small white calcareous nodules 

 have also been seen, just as in this basal Upper Gault at other 

 localities. In one part of the topmost layer, where the limonite- 

 band, C, dipping down slightly for a short distance, happened to 

 occupy a surface of weakness just below the top of the bed instead 

 of above it, we noticed that the limy nodules were flattened. The 

 matrix in this patch, immediately in contact with the overturned 

 Gault, was horizontally laminar and fissile, owing to a deformation 

 resulting from pressure. 



We can throw little light on the palaeontological characters of 

 this Upper Gault basement-bed. It is relatively unfossiliferous, 

 and we have done no more than prove that brachiopods occur in 

 it ; Kingena lima (Defr.) is the only species we have identified. 

 There can be little doubt that a certain number of the brachiopods 

 described by the late Mr. J. F. Walker, from bed D, came from this 



