HuTTON. — Geology of North-eastern Otago. 42l 



ments of volcanic rocks. The palagonite tnff I have already 

 described •^-hen mentioniug the Deborah volcano." 



A little north of Totara, on the west of the railway, the 

 limestone rests on tuffaceoiis clays which dip 10° S.W., but 

 which, towards the south, flatten to 4° S.W. In the railway 

 cutting at Tescheniaker's the limestone, here horizontal, passes 

 down into a coarse rubble of broken shells, coral, sand, etc., 

 and is underlain by about 8 feet of alternating beds of marl and 

 limestone, below which is a brown volcanic sandstone, 10 or 

 more feet thick, which appears to be derived from the degrada- 

 tion of volcanic ash, and not a true ash itself. It therefore 

 appears, so far as my observations go, that volcanic action took 

 place before and during the deposition of the marls and clays 

 underlying the limestone, but there are no volcanic ashes in the 

 limestone itself. The volcanic action was chiefly submarine, 

 but the water was shallow. 



The geographical distribution of the Ototara limestone has 

 been described by Mr. McKay. The dips I observed were as 

 follows : — At Cave Valley, 5° E.N.E. ; near Totara railway- 

 station, on west side of the road, 5° N.W. ; on the east side, 

 between the road and the railway, 4° to 10° S.W. ; at north 

 side of Deborah, 5° N.N.E. ; on south side of Oamaru Penin- 

 sula, 35° S.W. Now, Oamaru Peninsula, Deborah, and Enfield 

 are old volcanoes, consequently the Ototara series dips away 

 from the nearest volcanic centre. This shows, in my opinion, 

 that the Ototara limestone is the remains of several old coral 

 reefs built up round small volcanic islands near the coast, and 

 that it usually retains its original plane of deposition. Lime- 

 stones are known to be forming at the present day, at angles as 

 great as 33° and 35°, on the coral-reefs of Florida and the 

 Solomon Islands. 



Hutchinson's Quarry Beds. — This quarry is situated in the 

 town of Oamaru, on the east side of Oamaru Creek, close to the 

 path leading to the reservoir. It is now abandoned, but was 

 formerly used for lime for burning. The following is the section 

 displayed:— Feet. 



8. Dark-green sandstone ... ... ... 61 



7. Calcareous sandstone ... ... ... 8-10 J 



6. Conglomerate of volcanic rocks and 



compact limestone ... ... ... 10 



6. Volcanic clay ... ... .. ... H-2 



4, Compact limestone ... ... ... Of 



3. Volcanic clay ... ... ... ... Of 



2, Piubbly limestone ... ... ... 3 



1. Volcanic clay, with calcareous veins ... 13 



* To find this interesting outcrop, take the road from the Deborah 

 railway- station to the quarry, and, leaving the quarry on the right, strike 

 across the fields to the crest of the ridge. Then, looking down into the 

 Waireka Valley, the section will be seen on the left hand. 



fossils. 



