BY G. D. OSBORNE. 193 



eventually brings about the disappearance of the rock, and there is, therefore, an 

 overlap of the Main Glacial Beds upon the lower portion of the Glacial Stage 

 in the district to the east of Butterwick. Beyond the region of overlap the 

 eruptive rock again occurs, as in portion 52, Parish of Seaham, but the ex- 

 tension to the east is small, owing to the intervention of a heavy fault, by reason 

 of which the dellenite is next found along the course of Felspar Creek, eventually 

 coming out upon the Seaham-Clarencetown Road just at its shai'p bend above 

 Felspar Creek. Alluvium now conceals the deUenite to the east, until the 

 Williams Kiver is crossed, and on the left bank, immediately opposite Porphyry 

 Point, deUenite and potash-rhyolite are exposed on the hillside, partly ai'tificially 

 in a small quai-ry. From here the rock forms the capping and southerly-directed 

 slopes of a distinct ridge which trends E. 30° N. to Caswell's Creek. 



Good sections of the Main Glacial Beds are to be seen at various places in 

 the area, but the individual horizons do not outcrop over large areas in such a 

 way as to make it possible to trace them from place to place with ease. Further- 

 more, local development is a feature of some of the strata, especially the true 

 tillites. 



At Paterson the Main Glacial Beds outcrop in the Park and in the pad- 

 docks west thereof, and form a considerable amount of the low-lying land oc- 

 cupied by Webber's Creek, some distance further west. Passing east from Pater- 

 son Park they form the foundation of much of the southern portion of the town, 

 and can be seen near Douribang Village, on the Paterson- Seaham Eoad, and out- 

 cropping continuously along this road to within a mile of Buttenviek. To the 

 south of this road they extend little, but on the north and north-east gradually 

 increase in width of outcrop from Douribang towai'ds Dunn's Creek, where they 

 are developed in a plunging syncUne. In Dunn's Creek and its main tributaries, 

 excellent sections are exposed, and the stratigraphy is eleai-, while the record, in 

 the main stream, of a dip of 40° at E. 30° S., and in the fii-st tributary to the 

 east of a dip of 30° at N. 60° W. establishes the existence of the syncline men- 

 tioned. 



Fluvio-glaeial conglomerates, varves and glacial muds form part of the ridge 

 running from the western boundary of portion 18, Parish of Butterwick, to Big 

 Brandy Hill, as well as much of the lowlands to the south-west of this ridge. 

 On the east of the large fault near Butterwick, tiUites and conglomerates are to 

 be seen o^ the southern slopes of Big Brandy, and also along the banks of Bartie's 

 Creek. Hereabouts, the direct passage from the tuffs and conglomerates of the 

 lower portion to the Main Glacial Beds may be observed. 



The most chai-acteristic tillite in the whole area of the Main Glacial outcrop, 

 occurs on a small rise in the south-eastern comer of portion 38, Parish of Sea- 

 ham, the extent being limited. From here on to Seaham the glacial beds appear 

 to be mostly conglomerate and tillite, vai'ves not being conspicuous. Nearer 

 Seaham they may be seen in the road cuttings, and to the north outcrop right to 

 the right bank of Felspar Creek. 



The occurrences in the Seaham Cemetery and along the Maitland Road have 

 been fully described by Mr. Sussmilch. The base of the Main Glacial Beds 

 occurs at Felspar Creek, just near the point where the road crosses the creek. 

 Here they are very bouldery indeed, and owing to the strike coinciding in general 

 with the trend of the road to the south, they outcrop right along to the Seaham 

 Hotel. They also extend to the west of the road and are overlain by tuffs which 

 have their maximum development in portions 62 and 63. These are the equiva- 

 lent of the tuffs occurring along the ridge which stands to the east of the main 



