184 GEOLOGY AXD PETEOGEAPHT OF CLARENCETOWN-PATEESON DISTRICT, i., 



account of the greater development of the Volcanic Stage at Mt. Gilmore than 

 elsewhere the maximum thickness of this Stage (allowing for overlapping of 

 flows) is 2600 feet, while of the Glacial Stage the Lower Portion (equivalent of 

 the Mt. Johnstone beds) has a thickness of 2100 feet, the Paterson type of del- 

 lenite and toscanite, 290 feet, and the Main Glacial Beds, 1840 feet as measured 

 at Seaham by Sussmilch. 



Maximum Thicknesses of Stages of the Kuttung Series. 



Basal Stage 



Conglomerate chiefly 1500 Feet 



Tuffs with conglomerate bands 740 



Tuffs with L. vellheimianum 10 „ 



Tuffs with pebbles 50 „ 



Volcanic Stage 2600 „ 



Glacial Stage 



Lower Portion (equivalent of IVft. Johnstone Beds) 2100 



Toscanite (Paterson type) 290 



IVlain Glacial Beds 1840 „ 



Total .. 9130 „ 



An excellent summary of the geological history of the Carboniferous Period 

 has already been given by Mr. Sussmilch. 



REGIONAL GEOLOGY. 



The Bueindi Series. 



The representatives of this Series at Hilldale are delimited to the south by 

 a fault which has in part determined the scarp of Mt. Douglas on the northern 

 side. The individual horizons in the Series are not very persistent, but the mud- 

 stones and shales outcropping in portion 100, Parish of Barford, can be traced 

 through to the north-west and may be seen in the railway cuttings just west of 

 Hilldale Station. The Burindi outcrops are then continued beyond the limit of 

 the map towards Gresford on the Allyn River. The fossiliferous limestones and 

 calcareous tuffs of portions 100 and 102, Parish of Barford, do not persist as 

 far west as the railwaj' line, because here, on the strike of these rocks, sand- 

 stones are found. It is not possible that faulting is responsible for these fea- 

 tures, since the mudstones which underlie the limestones show no evidence of dis- 

 placement. 



The Burindi rocks west and north of Clarencetown occupy a large area. 

 About half-way between Clarencetown and Wallarobba, small strike faults have 

 been responsible for some repetition of the units of the Burindi beds, while 

 larger faults occurring near these two localities have caused apparent inter- 

 bedding of the Burindi with the Kuttung Series. Thus, on the Limeburner's 

 Eoad, a little to the east of the Clarencetown Bridge, one finds a small oc- 

 currence of marine mudstones striking meridionally and accompanied by Kuttung 

 conglomerate to the west and east. Of the Burindi rocks to the west and north- 

 west of Clarencetown, the Glen William fossiliferous elaystones and the andesite 

 crossing the Dungog Road in portion 206, Parish of Uffington, are the most 

 important. 



The former rocks strike north and outcrop all the way along the road from 

 Clarencetown to Glen William village, maintaining their individuality for about 

 four miles. The igneous horizon can also be traced about the same distance to 

 the north, disappearing in portion 21, Parish of Wallarobba, while its extent to 

 the south-west is little beyond the Dungog Road. 



