Thomson. — Geology of Middle Clarence and Ure Valleys. 343 



Bluff i?rrer.— McKay describes the conglomerate as much thicker than 

 elsewhere to the north-east, and as very coarse in its lower part, containing 

 blocks of Amuri limestone 10-35 ft. in diameter, together with boulders 

 of Clarentian rocks and fossiliferous Tertiary concretions mingled with 

 well-rounded pebbles of sandstone and volcanic rocks. The higher beds 

 of the conglomerate are much finer than the middle and lower parts, and 

 alternate with beds of sandstone, forming a passage to an overlying series 

 of sandy clays with ribs of hard sandstone which are difficult to distinguish 

 from the '' grey marls." 



Seymour River. — As has already been stated in describing the " grey 

 marls.'' it appears improbable that the great Marlborough conglomerate 

 is present in this section, and more likely that the agglomerate described 

 by McKay really represents an old talus deposit. The only doubt is caused 

 by his reference to the presence of '' blocks and concretions of middle 

 Tertiary rock." 



Decuhnau's Creek. — Although this section lies outside the area here 

 described, the relationships of the great Marlborough conglomerate are of 

 great importance in an}' discussion of its origin. Deadman's Creek lies 

 immediately soiith of Deadmans Hill on the coast south of Kekeransu. 

 Hector and McKay have referred to it as Shades Creek, but the true 

 Shades Creek is still farther to the south. 



The sec[uence commences with Amuri limestone or Weka Pass stone, 

 here argillaceous and with many layers of niudstone. This dips north-west 

 — i.e., up-stream — and is succeeded by " grey marls." Above this comes 

 a strong band of the great Marlborough conglomerate, some hundreds of 

 feet thick. Unfortunately the junction with the " grey marls " is obscure, 

 but the lower 15 ft. of the conglomerate consists of fine sandstones. The 

 succeeding 60 ft. of the conglomerate is fairly coarse, although blocks 

 larger than 3 ft. in diameter are rare. The majority of the boulders are 

 well rounded, and they consist preponderatingly of pre-Notocene grey- 

 wackes and jasperoids and Clarentian sandstones. Volcanic rocks similar 

 to the Clarentian lavas are commoner than usual. Boulders of Amuri 

 limestone are moderately abundant, and flints are occasionally seen. 

 Boulders of fossiliferous Tertiary sandstone are not very common, and 

 are generally of small size and uniform in character. 



The gorge of the creek in the conglomerate is impassable, and the creek- 

 bed below is described by McKay as " choked with huge fossiliferous blocks 

 from 3 ft. to 15 ft. in diameter, from which a collection of Awatere fossils 

 of such variety and excellence could be made that the like could not be 

 obtained from any one locality where the beds occur in sltu.^' Hector 

 agrees with McKay in believing that these blocks are derived from the 

 conglomerate. As a matter of fact, no blocks of such size were observed 

 in the conglomerate, and those in the creek-bed are undoubtedly derived 

 from a series of shell-beds in situ apparently resting on the conglomerate. 

 To these I have given the name of the Deadman's Creek beds. They 

 consist of sandstones crowded with shells along certain layers, some bands 

 containing predominantly PoUnices, others Turritella, and others Glycymeris. 

 About 100 ft. of these beds are exposed in the cliffs, and another 100 ft. 

 along the creek - bottom, where they contain pebbles, the majority of 

 which are of greywacke and quartz, but one pebble of basalt was observed, 

 and some blocks of fossils, apparently derived. The junction of these 

 beds with the underlying conglomerate was not clearly made out. The 

 dip of the two rocks is the same — about 60° up-stream — and in the cliffs 



