Vol. 62.] GEOLOGY OF DUNEDLN (NEW ZEALAND). 389 



the formation of an extensive anticlinorium and consequent pro- 

 longed denudation. 



The rock occurs on the western outskirts of the present district, 

 and fragments are frequent in the Port-Chalmers Breccia. Else- 

 where it extends for 100 miles to the west and 50 miles to the north 

 and south of the district, in unbroken continuity except when 

 fringed on the margin by Tertiary formations, or where river-valleys 

 or basins have been wholly or partly filled by late Tertiary or 

 recent accumulations of gravel or other alluvium. 



Where the schist is in contact with other rocks of this district, it 

 has a fairly-uniform dip of about 30° in a direction S. 40° E. 



Kainozoic calcareous sandstone. — In hand-specimens this 

 rock is of a light grey colour, quite fine-grained. Sections show a 

 number of tests of foraminifera, among which forms like Textu- 

 laria, Cristellaria, and Globigerina can be distinguished. The 

 sand-grains are subangular, and consist solely of quartz. 



The Tertiary sandstones and limestones have a thickness of about 

 1000 feet at Whare Elat, where the schist is exposed below them 

 and the basalt of Swampy Hill is to be seen above them. 



The main part of the formation is a white calcareous sandstone,, 

 which forms vertical marine cliffs at Sea View and at SeaclifT, in 

 the southern and northern part of the district respectively. It 

 has, in these two localities, a slight dip (5 to 10°) westward. Near 

 Brighton, where the Tertiary deposits rest upon the mica-schist, the 

 base of the formation is a clean white quartz-sand, upon which rests 

 a seam of inferior brown coal. This is covered by a fine conglo- 

 merate, consisting of pebbles of quartz evidently derived from the 

 schist. In the conglomerate are many fragments of shells of Ostrea, 

 and abundant specimens of Actinocamax, a late form of belemnite. 

 The conglomerate is succeeded by the calcareous sandstone pre- 

 viously mentioned, and this is again covered by white and green 

 sands, the latter containing sharks' teeth and Waldheimia. 



The Tertiary formations are not found above the sea-level in most 

 parts of the district, but they rise in Swampy Hill to a height of 

 1700 feet above sea-level. In Mornington there is a pit whence 

 the upper white sand is obtained, 500 feet above sea-level. In the 

 Glen quarry at Caversham, half a mile distant, the same deposit is 

 found 30 feet above sea-level. 



On the Otago Peninsula there is an outlier of the calcareous 

 sandstone at the Sandymount schoolhouse. Here it dips 30° south- 

 westward at 560 feet above sea-level, although it is nowhere exposed 

 at the neighbouring sea-margin except on the opposite side of 

 Hooper's Inlet, where the dip is in the same direction, but steeper. 

 On the opposite side of Otago Harbour, a small outcrop at Blanket 

 Bay dips 20° north-westward, and another in Dowling Bay 40° north- 

 north-westward. 



These facts show that the Tertiary formations have at present a 

 highly-irregular surface. It is probable that this irregularity was 

 chiefly caused by erosion before volcanic activity commenced. 



