Thomson. — Geologii of Middle Clarence and Ure Valleys. 319 



followed by dark sandy beds with concretions, the ouier part of whieli 

 consists of cone-in-cone limestone ; and these are succeeded by the Amuri 

 limestone." 



Gentle Annie Stream. — The Notocene beds continue from the Biulf 

 River into the Gentle Annie Stream,, where the Amuri limestone occurs 

 in a syncline. The Clarentian beds below tiae limestone to the south-east 

 are not well exposed, b\it the presence of muddy sandstones di])ping to 

 the north-west was observed. 



Herring [or Sei/monr) River. — The exposures of Clarentian rocks described 

 from Isolated Hill Creek, Coverham, and the Mead to the Crentle Annie 

 all belong to a continuous strip forming the lower member of the Notocene 

 rocks involved in the great Clarence fault. From Bluff Hill to the Gore 

 River there are other outcrops of Notocene rocks involved along the more 

 north-easterly parallel faults, except for the large outcrop between Bluff 

 Hill and Limestone Hill, which seems to occupy a synclinal depression. 

 Many of these outcrops include only Clarentian rocks, while in others a 

 nearly complete succession of the Notocene is included. The Clarentian 

 rocks in this area commonly commence with terrestrial coal-measures, 

 and volcanic rocks are well developed. The most complete and typical 

 succession is that of the Herring River, which will be considered first, 

 although it disturbs the geographical sequence of the account. 



In the lower Herring River the unconformity of the Clarentian and 

 pre-Notocene rocks is well exposed. The latter consist of concretionary 

 (" cannon-ball ") sandstones and thin argillite bands, striking N. 15° W., 

 with a very steep dip to the west. The Clarentian rocks strike, at the 

 base, N. 30° E., and dip 44° to the north-west — i.e., down-stream. The 

 Notocene series is folded into a syncline and anticline before reaching the 

 Quail Flat fault-line near the junction with the Clarence River, and the 

 syncline brings the Amuri limestone down to the river-level, thus separating 

 two exposures of the higher part of the Clarentian beds. 



The lowest rocks are coal-measures, 50 ft. thick, forming cliffs of a 

 reddish colour. The series commences with a seam of lignite a few feet 

 thick, followed by carbonaceous shales, grits, sands, and ferruginous sand- 

 stones, with thin seams of lignite. Some of the sandstones and shales are 

 crowded with plant fossils. Then follows a series of volc;inic rocks about 

 320-340 ft. in thickness. Four well-marked lava-flows can be recognized, 

 but there may be more. The rocks have not been examined microscopic- 

 ally, but appear to be olivine basalts. The lowest lava is not columnar, 

 and is 60-70 ft. thick, and it is suceeded by more coal-measures, varying 

 from 7 ft. to 15 ft. in thickness. The second flow, which is coarsely porphy- 

 ritic, is columnar for the lower 20 ft.. passing into breccia for the upper 20 ft. 

 The third flow of fine-grained basalt is 15 ft. thick, and is columnar through- 

 out. The fourth flow lies 150 ft. farther up, and is about 50 ft. thick. 

 The outcrops of the interbedded rocks at river-level are covered by basalt 

 screes, but may be exposed on the higher slopes of the valley-sides. The 

 fourth lava is iminediately followed by mudstones. 



Farther down the stream the section of the succeeding Clarentian beds 

 is far from continuous, as the banks on each side are much sli})ped, 

 probably owing to the predominance of loose sandy beds. Such rocks as 

 are exposed are mudstones, sandstones, sometimes with pebble-beds, and 

 a thick series of mudstones with yellow efflorescence in beds about 1 ft. 

 thick, alternating with soft sandstones in beds of 18 in. to 2 ft. thick. 

 Higher up in the succession the mudstones become more massive and the 



