R. M. Brydone — Further Notes on the Trimmingham Chalk. 19 



who took in February, 1901, the photographs repi'oduced as 

 Plate II, Figs. 2 and 3, and Plate III, Figs. 4 and 5. Fig. 2 shows 

 the bluff as seen from a point on a line drawn through the bluff 

 parallel with the beach-line. It will be noticed that one of the 

 lines of flints appears to be vertical. That this is an illusion 

 can be seen from Fig. 3, which was taken from a point 

 approximately on the strike of the same line of flints, which 

 (as I stated in my previous pamphlet, and have several times since 

 checked) is not parallel to the beach -line. The appearance of 

 verticality is due to the surface presented being oblique both to the 

 line of vision and to the horizontal plane. 



Fig. 4, Plate III, shows a very interesting development on the 

 north side of the bluff. A deep bay had been hollowed out with 

 a long south side and very short north side. The south side 

 was formed by first the bluff itself and then chalky clay, as 

 shown in fig. 1 of my previous pamphlet. But the clay now 

 proved to be only a narrow triangular mass, succeeded by 

 a sloping bank of chalk which formed the rest of that side 

 of the bay. The head of the bay was formed of talus from the 

 cliffs above, and apparently concealing the connection of the 

 sloping bank of chalk with the chalk which emerged again to 

 form the short north side. This north side ended in a clean-cut 

 cross section, which showed it to consist of a layer of chalk from 

 two to three feet thick resting on chalky clay with an apparent 

 bedding parallel to the base of the chalk, the junction plane 

 dipping seawards at an angle of about 55°. The whole of the 

 chalk exposed behind the triangular mass of clay was grey, and 

 exhibited many peculiarities which will be dealt with fully later on. 



Fig. 5, Plate III, gives a close view of the pinnacle of clay and its 

 immediate surroundings, and there are a number of points of interest 

 about it. One is the distance from which the clay runs in under the 

 chalk on either side. Shortly before the photograph was taken the 

 sand was still further cleared away and the clay extended quite two 

 feet further under the bluff. In this connection it is to be observed 

 that a junction between the chalk and the clay has been seen on the 

 foreshore close by for a distance of some 30 yards, throughout the 

 whole of which the clay is running in under the chalk for a distance 

 of at least nine inches, and may, for all appearances, underlie it 

 altogether. There are many other points on the foreshore where the 

 junction of chalk and clay has been observed, and in all the plane of 

 junction is either vertical or else almost horizontal with the clay 

 running under the chalk. Again, in the case of a fault on the 

 foreshore almost opposite the north bluff, the chalk on either side 

 of the fault has at one point been broken away so as to form 

 a long narrow steep-sided pool about 18 inches deep. The bottom 

 of this pool is formed by what appears to be the truncated top of 

 a dome of clay, composed of fairly regular concentric layers of clay 

 of varying colours, suggesting very strongly that the clay has been 

 forced up from beneath into a cavity or crack. The point at which 

 this occurs is at least 30 yards from the nearest exposure of clay. 



