Benson.—Structural Features of the m of Australasia. 127 
поа platform which rises above the sea in the Fiji Islands, would 
seem to remove that ridge from the tectonie control of the Australasian 
structure rather more than would be in accord with the conceptions 
entertained by Suess and Andrews (1922). Further divergencies from the 
Moluccan type of structure of tho Australasian margin will be seen below 
in the account of New кка; where the folded arc passes into а more 
or less continental platfo 
Passing farther to бег south, 2 is noted that the New Caledonian- 
Loyalty Island ridge is not continued far beneath the ocean, but is 
Caledonian axis, the Norfolk ridge rises to within fathoms of the 
sea-surface, and continues with a slightly sinuous but generally south- 
south-easterly direction towards the centre of the North Island of New 
Zealand, meeting it to the west of the short submarine prolongation 
of the North Auckland Peninsula. The basaltic mass of Norfolk Island, 
rising en this ridge, contains a voleanic tuff with fra era crystal- 
situated at a s dépth ар less than 1,000 fa д, reaching almost to the 
coastal shelf of Queensland, from which it is separated by a deep, narrow 
trench. From this a second wider and more continuous ridge extends 
south-south-easterly to the neighbourhood of Cook Strait. Lord Howe 
Island (composed of relatively ancient and probably late Tertiary basalts 
and agglomerates) rises from the western side of this long submarine 
plateau-ridge, which is separated from the Norfolk ridge by the New 
Caledonian trench, between 2,000 and 3,000 fathoms deep; and a like 
depth, the Thompson Trou gh, divides it from Australia. The special 
interest attaching to Lord ake Island lies in the occurrence in i of the 
remains of the giant tortoise Miolania, which is also: 
Pleistocene rocks of Walpole Island, of Queensland, and паа, (?) 
“ As 
of Patagonia. Miolania must have been a land-anim al, its discovery 
in regions so remote is sometimes cited as one praof of the former existence 
of a great Antarctic continent uniting the lands in question."* This, and 
the position of the broad suboceanic ridges, suggest a louis of a 
general south-south-easterly grain in the structure of the floor of the Tasman 
, which may thus be the foundered former continental land. Such an 
indication, however, clearly does not approximate to a proof. 
The tp formations of New Zealand may be classed broadly 
into a pre-Cretaceous and a Middle Cretaceous - оез series. The 
following tectonic se dou concerning it may now be noted. The most 
ancient rocks are visible along the western slopes of the South Island. 
According to recent ideas, they are crystalline schists and gneisses lying 
unconformably below the ‘Ordovician sediment; but the possibility that 
they are (partly at least) an extremely altered facies of the Ordovician 
rocks cannot be held to have been excluded. Their strike is very variable, 
ranging from W.N.W. to N.N.E., and is not noticeably different from the 
strike of the Она acer rocks. Its varying trend is possibly due to the 
refolding along approximately meridional lines of rocks originally folded 
n a north-westerly strike. A limited area of Silurian sediments also 
* British Museum Guide to the Fossil Reptiles, &c. 
