Ol.IVEH. — (Irolixjij of Ijic KciiiKidic lxl(ni(h. 529 



thill even strata of tutl's which 1 take to be of submarine origin (referred to 

 as the "older submarine series"). The stratification is perfectly even, 

 though the beds are now tilted in short sections alternately to east and 

 west, as though great lateral pressure had been brought to bear. In two 

 places they are pierced by small intrusions of augite-andesite. 



At Hutchison Bluft' a core of lava, about 8 m. wide, of burnt and scori- 

 aceous appearance has burst through the submarine tuffs (tig. 3). On 

 the western side a stream of augite-andesite 1 m. to 4-5 m. thick (No. 29) 

 descends from near the top of the core at an angle of about 1U°. 



Further to the east is another intruson of augite-andesite (No. .30). 

 Surrounding the lava the tuffs are burnt to a brick-red colour. 



The Terraces are a comparatively recent addition to the north side of 

 Sunday Island, and at the base of Big and Expedition Hills abut against 

 <'lilfs which are a direct continuation of the sea-cliffs extending to Hutchison 

 Bluff. They are composed entirely of pumice tuffs arranged in slightly 

 irregular but generally horizontal beds, apparently of subaerial origin. A 



specimen of pumice, Mr. 

 Speight infoi'ms me, is 

 andesitic in character. 

 Fragments of lava 

 rocks, sometimes 2 m. 

 or 3 m. in diameter, are 

 strewn thickly through- 

 out the pumice tuffs. 



Fig. 3. — Intrusion of Augite andesite at Hutchison At the base along the 

 Bluff, Sunday Island. shore-line there is for 



the most part a boulder 

 beach composed of fragments too heavy to be washed away by the sea, 

 which is gradually eating away the comparatively loose tuffs. Among the 

 boulders I gathered samples of hornblende-granite* and andesitic pitch- 

 stone (No. 2), and noted that the largest pieces of lava were identical 

 in appearance with the andesites from a large flow of lava in the 

 Sunday crater. Logs of charred wood, recognized as that of Meirosideros 

 vUlosn, the most abundant tree on Sunday Island, were noticed in the 

 tuffs at the base of the cliff. The section exposed at FleetAvood Bluff shows 

 No. A Terrace to have been formed during two distinct periods of eruption, 

 in the interval between which two wide valleys some 20 m. deep were formed 

 in the first deposited beds. On the hillside above No. 1 Terrace, about 

 80 m. above sea-level, is a large Ijoulder of hornblende-granite. 



On the east coast of Sunday Island, at sea-level, is a stratum composed of 

 rounded evidently water-worn boulders of all sizes up to 2 m. in diameter, 

 cemented together by a sandy matrix. Above this and conformable to it 

 are the newer submarine tuffs, intersected in Coral Bay by a large dyke 

 running east and west, and overlaid by a flow of basalt (No. 36), above 

 Avhich are pumice tuffs. 



In South Bay, near D'Arcy Point, at sea-level, is also a bed similar to 

 that on the east coast, containing water-worn boulders. Several dykes 

 with a general north-west trend intersect the newer submarine tuffs of South 

 Bay. On the shore several small rounded stones of hornblende-granite 

 were seen. 



* For a description of the hornblende-granite s?e Speight, 1910, p. 251. 



