Speight. — The Tertiary Beds of the Trelissick Basin. 337 



to the ground ; but before dealing with it more fully it will be best to 

 describe the relations between the various members of the overlying series 

 as it is developed in different parts of the area. I have retained the 

 name " Pareora," since it is convenient to describe a particular facies of 

 Tertiary deposits occurring in numerous places in Canterbury besides the 

 name locality — that is, shore deposits of sandy layers with broken shells, 

 occasionally with concretionary bands, which form the top of the Tertiary 

 fossiliferous beds ; but I do not intend to imply that they should be classi- 

 fied as distinct from the Oamaru series as developed in its typical district. 



The relations of these beds to the underlying strata are best seen in the 

 neighbourhood of the junctions of the Thomas River and Home Creek with 

 the Porter River. In the former, from the site of the old dipping-yards 

 down-stream, occur the following : — 



Sandy shales ; thickness exposed, 10 ft. 



Lignite, about 2 ft. thick, dipping S.W. 30°. 



Greenish-grey sands. 



Yellowish sands, dipping S.W. 20°. 



Dark greensands. 



Yellowish sands. 



Dark greensands, extending past the junction of the creek on the 



south. 

 Greenish-grey sands. 



Broken-shell beds, with sands, 12 ft. thick. 

 Greenish-grey sands. 

 Broken-shell beds, 2 ft. 



Concretionary sands, with broken-shell bands. 

 Broken-shell beds, 3 ft. 



Sands, weathering rusty grey, sometimes a light-coloured greenish- 

 grey, 100 ft. thick. 

 Calcareous sandstone with many shells; thickness 15ft. (?), strike 



N.N.W., with a dip to the W.S.W. 20°. 

 Limestone. 

 The relations between the lower bed and the limestone are well seen at 

 the present time owing to a great fall of rock just above the junction of 

 the Thomas with the Porter. (Plate XXII, fig. 2.) Immense blocks lie 

 here with thick layers of shells in excellent state of preservation. These 

 were not available in the time of Hutton or McKay, and the overhang 

 which the rocks no doubt had at that time would prevent their proper 

 examination, the dangerous nature of the locality being remarked by Hutton. 

 In none of the contacts, however, is there any sign of an erosion surface. 

 In the neighbouring Home Creek the following sequence is exposed : — 

 Calcareous concretionary sands with broken-shell bands, the shell- 

 remains being concentrated into a narrow layer 6 in. to 12 in. 

 thick ; total thickness uncertain. 

 Sandy beds, greenish in colour, with broken-shell layers, 15 ft. 

 Calcareous concretionary sands, 2 ft. 

 Greenish-grey sands, 3 ft. 

 Sandy beds with broken shells, very much current-bedded, 5 ft. 



exposed. 

 Broken-shell beds with sands, sometimes with hard bands, sometimes 



looser, 20 ft. thick. 

 Sands weathering a rusty brown, with brown concretionary layers 



and shell-fragments, 80 ft. 

 Shelly beds with loose irregular light-greenish-grey sands. 25 ft. thick. 



