Thomson. — (rioloiin of Middle Ctartnce and Ure Valleys. 



329 



beds of the limestone follow the truncated surface regularly, but a few feet 

 up the beds are sharply folded in the manner shown in fig. 6. It is, of 

 course, possible that the surface of separation is not a true unconformity, 

 but a fault or thrust-plane ; but I observed no sign of crushing or slicken- 

 sides along the surface. 



On the north-west wing of the anticline, in a clif^" some distance above 

 the river-bed and about half a mile above the junction with the Clarence 

 River, there is a good ex])osure of beds from the u|)per Clarentian to the 

 Weka Pass stone. The apparently unconformable nature of the junction 

 has already been described (p. 320). The Amuri limestone is about 200 ft. 

 thick, the lower 150 ft. consisting of a thin-bedded alternation of argillaceous 

 shalv limestone with harder white bands which are slightly glauconitic. 



Fig. 6. — Diagram of junction of Amuri limestone and Clarentian greensandstones, 

 south-eastern wing of syneline, Herring River. Only a few of the alternations 

 of chalky and marly limestone can be shown, a, tussock; b, talus; c, sands; 

 d, calcareous greensandstone ; e. Amuri limestone. 



while the upper 50 ft. is a glauconitic calcareous mudstone. This is suc- 

 ceeded conformably by 4 ft. of bright-green glauconitic calcareous sand- 

 stone with dark phosphatic nodules, and this in turn passes without a 

 break into a dirty brown-green greensand. Both the latter beds contain 

 Oamaruian fossils sparingly. 



A few inches of nodular rock follows, very similar to the phosphatic 

 greensandstone separating the Amuri limestone and Weka Pass stone in 

 the Weka Pass. This is in turn succeeded by a thin bed of limestone, 

 15 in. thick, containing small green fragments which appear to be of 

 volcanic origin. The next bed is a mudstone, about 6 in. thick, with 

 numerous '' fucoids," and above this is another bed of limestone, about 

 6 in. thick, with green fragments. Above this comes about 6 ft. of fine- 

 grained basic tuffs alternating with thin brown calcareous sandstones. The 

 next 10 ft. is occupied by dark tuft's ; on these rest another series, about 

 5 ft. thick, of limestones with green fragments, in beds of about 1 ft. thick, 

 separated by soft shaly material. Finally there is another 4 ft. of dark 

 tufts, passing up gradually into a massive limestone some hundreds of feet 

 thick. The latter was not examined in detail here. On the opposite side 



