^94 Mr. Brockbank and Mr. C. E. de Range on 



with small holes. The colour also is peculiar, being a dark 

 liver-coloured purple — with yellow stain lines, and deeper 

 purple blotches. Veins of calcite run across the blocks, 

 and Spirorbis is not visible, if at all present. The lime- 

 stones have a brecciated appearance, the fragments cemented 

 by calc-spar. This group of limestones appears to have 

 been formed in troubled waters, and under very disturbed 

 ■conditions. The presence of the hematite iron resting upon 

 them is of interest, as shewing the transition period at 

 which these beds were deposited and formed just before the 

 Permians. A thin section of this limestone looks like a 

 smear of hematite on the glass slide, and when viewed under 

 the microscope it is seen to be made up of small angular 

 fragments, everywhere iron -stained. Many comminuted 

 shells are present, but no perfect shells, or Entomostracay 

 although abundant fragments of both. It is interesting 

 thus to observe in the microscope the characteristic 

 evidences seen in the outward appearance of the rock and 

 its surroundings. These limestones rest upon a series 

 of shales and marls, 17 ft. thick, commencing with a 

 violet purple, and passing in distinct beds of varying 

 colours, gradually, to a deep rosy red. The beautiful grada- 

 tions of colour in these beds interested us much, so that we 

 used to call them the "Esthetic" marls. In the section, 

 Plate v., as nearly as possible, the exact colours taken from 

 actual samples of the marls are reproduced. These marls 

 were evidently formed by the grinding down of the lime- 

 stones and red clays, and were re-deposited under very 

 quiet conditions, in still waters. The beds were perfectly 

 regular, the colour^ varying like the leaves of a book, green 

 grey, brown, and pink alternating in beautiful sequences, 

 the mass gradually deepening in redness towards the base, 

 as is usual in this section. The red hematite clay at the 

 base of these marls was found by Mr. Bone to contain 

 10*55 P^^ c^"t of iron, and was highly calcareous. 



