190 GEOLOGY AND PETROGRAPHY OP CLARENCETOWX-PATERSON DISTRICT, i., 



region surveyed. Tliey are seen on the North Coast Road at the foot of Mt. 

 Johnstone, and in the paddocks immediately to the east of the road. They also 

 outcrop in portion 154, Parish of Barford, near its junction with portion 156. 

 The rocks are always associated with dacite, — in the latter locality with a dacite 

 carrying a multitude of peculiar inclusions which are made up almost entirely 

 of spherulitic structures. The soda-rhyolites in question have never been found 

 to the east of the Tucker's Creek locality. 



The somewhat remarkable rocks described as volcanic conglomerates, etc., 

 can be traced almost continuously from the base of Mt. Johnstone to near the 

 Langlands Estate. As was pointed out above, there are in general two types 

 of rock, and in this connection there seems to be a distinct change in nature 

 between the outcrop in portion 154, Parish of Barford, and that near Tumble- 

 down Creek in portion 147, Parish of UfRngton, where the rock contains rounded 

 inclusions of felsite up to the size of an egg. Near Glenoak the outcrop is brown 

 in colour, and can be seen just at the junction of the main road and a settler's 

 road leaving the former near the western boundary of portion 155, Parish of 

 Uffington. Here the rock is adjacent to a fault plane and its displaced equivalent 

 to the east is found on the Langlands Estate, beyond which it is not known to 

 occur. 



The majority of the other true tuffs are fairly limited in extent, but those 

 which contain sandy and conglomeratic sediment have a wide areal distribution. 

 Thus the tuffs both underlying and succeeding the hypersthene-andesite are well 

 in evidence all the way from Martin's Creek to Clarencetown, particularly so to 

 the east of Martin's Creek Station and to the north of the school, where the 

 conglomerate content is very predominant. The conglomerates overlying the 

 biotite-quartz-keratophyres outcrop extensively in portions 54 (Barford) and 147 

 (Uffington), and to a less degree near the railway line just south of Martin's 

 Creek (see map). 



At Mt. Gilmore the development of these rocks is also considerable, but the 

 average size of the constituent pebbles is much less than in the western districts. 

 At the northern end of the ridge the conglomerates become still less coarse in 

 texture and there is a local intercalation of a felspathic grit or tuff which does 

 not occur elsewhere. 



Sugar Loaf Hill, a conspicuous landmark in portion 148, Parish of Uffing- 

 ton, is composed of conglomerates which appear to belong to the series under 

 discussion, the stratigraphical relationship of the Sugar Loaf outcrop to the 

 surrounding rocks being undetermined. 



(iii.) Glacial Stage. 



The widespread nature of the rocks forming the lower portion of the Glacial 

 Stage can be appreciated when one realises that, in spite of the effects of hea^'y 

 faulting involving pronounced meridional displacement in most cases, it is pos- 

 sible to draw a line in a direction east 20° south,, from a point a little to the 

 south of Mt. Johnstone right across the area mapped, to Caswell's Creek, distant 

 ]3 miles, the line traversing almost entirely the outcrops of these rocks, the ex- 

 ception being a small area of Volcanic Stage rocks near Glenoak, alluvium, of 

 course, not being considered. 



Starting at Vacy, at the confluence of the Paterson and Allyn Rivers, rocks 

 of the lower portion, with the exception of the varves, are strongly developed 

 and form, for the most part, the ridge which stands up 1000 feet above the 

 valley of the Paterson River, and trends south to Johnstone Trig. Station. They 



