Bone Clay and Associated Basalts. 75 



tinuecl in the Ordovician bed rock. An. upper level at 200ft. 

 passed into a stratified black clay with much carbonaceous 

 matter. The lower level at 320ft. passed at a distance of 

 about 360ft. from the shaft into a tumultuous mass of volcanic 

 ejectamenta, containing large blocks of basalt and a smaller 

 quantity of blocks of the bed rock. The deposit is quite 

 unstratified in this level. The largest block is said to have 

 measured 20ft. in length. The contact with the bed rock on 

 both sides of this deposit is inclined inwards and blocks of 

 the bed rock are commoner near the north-west contact. 

 From this level a rise was made which passed into the black 

 clay at 238ft. below the surface, and was connected by a 

 drive on an incline to the upper level. At the top of this 

 rise the first bones were found, viz., part of the head and 

 lower end of the left humerus of Macropus faunus, as ex- 

 plained in Mr. De Vis' notes. The remainder of the Ijones 

 were found in the connecting drive, which was driven from 

 the rise towards the upper level. All the bones as found con- 

 tained much pyrites, as did also the black clay in which they 

 were found. This was more evident before treating them with 

 size to preserve them. Parts of the hind limbs of two indi- 

 viduals and a skull of one were taken out by myself from the 

 .sides of this drive. 



The clay beds dipped irregularly at low angles for the most 

 part, and at the junction with the bed rock dipped from the 

 line of contact. There were numerous surfaces of motion in 

 the clay, and nearly all the longer bones were much fractured 

 when first found in the clay, but usually with the pieces in 

 their proper relative positions — showing that the fracturing 

 was due to causes affecting them after burial. 



A similar deposit was struck in another rise from the lower 

 level. An intermediate level from this rise was driven north- 

 easterly to a distance of 620ft. in a direct line at a depth 

 of 295ft., or 25ft. above the bottom level. This for the 

 greater part of its length showed interstratified sedimentary 

 and volcanic materials, with blocks which had evidently fallen 

 on the soft beds, disorganising the coarser ones and fracturing 

 or bending the finer ones. No recognisable organic remains 



