At Kawhia, Tauranga, Golden Bay, and Waiau Mouth valleys, now in part drowned or infilled, were excavated, when the land was at a higher level than now, in the deposits and coastal terraces formed during the 200–300 ft. standstill. At Kawhia the valleys are filled with sands and silts to a height of over 100 ft., so that there has been a later depression of that amount. This was almost certainly the same depression and pause during which the 120 ft. coastal terraces were formed. At the other localities mentioned no precise observations as to the amount of infilling have been made. The buried forests and old land-surfaces at Thames, Coromandel, Opotiki, and Gisborne, and those of the Hamilton (70, p. 36; 73, p. 459; 75, p. 410), Taranaki, and Christchurch districts, probably belong to this period of oscillation. The submerged forests of other parts of New Zealand, most of which occur at sea-level on the coast, may have been formed during slight movements of still more recent date. This especially applies to the scrub - covered land - surfaces occurring a little below high - tide mark in Manukau, Raglan, Aotea, and Kawhia inlets. The inlets last mentioned, together with those of Kaipara and Tauranga, are formed by the drowning of valleys in part carved in Pleistocene deposits; Tauranga is entirely in these beds. They correspond in size among themselves, and also to other inlets round the coast of New Zealand formed by the drowning of stream-valleys. This suggests that all these features were produced by the same movement of depression, which occurred between the Tongue Point and Awakino erosion cycles. There are, however, no data by which the depths of these drowned valleys can be compared, since all, except the Marlborough Sounds, are largely infilled. Cotton concluded that these last-mentioned inlets had been produced by a subsidence of the land of between 250 ft. and 500 ft., and such bores as penetrated the beds deposited in the drowned valleys do not contradict this conclusion. The layers of vegetable material and the other terrestrial beds that are penetrated by the deeper bores at Christchurch and Chertsey probably belong to the Middle Pleistocene period. Progradation of this portion of New Zealand was continuous throughout Pleistocene times. At Chertsey gravels and sands more or less oxidized extend to 1,500 ft. below sea-level, at which depth they pass into sands and clays probably of marine origin. It should be noted that the bottoms of several of the fiords of western Otago are at a similar depth below sea-level. In the North Island the greatest known depth at which surface deposits occur is in a bore at Horotiu, in the Hamilton district, where peat-beds occur 550 ft. below sea-level. This bore when abandoned was still in unconsolidated deposits which had accumulated in a tectonic depression. At Thames, in an adjacent structural trough, loose sands and silts are known to occur to a depth of 1,100 ft., but those beds do not furnish proof that the land in this area was ever elevated to this extent. Post-Tertiary Volcanic Rocks. The post-Tertiary volcanic rocks of New Zealand are confined to the North Island. They consist of the three following groups: (1) Basaltic rocks that occur at many points near the west coast from Kawhia to Auckland and in North Auckland Peninsula; (2) rhyolitic flows, breccias, and tuffs that cover large areas in the Taupo-Rotorua zone, and occur near Waihi and probably other parts of Hauraki Peninsula; and (3) the andesitic cones of Egmont, Ruapehu, and adjacent mountains, Edgecumbe, White Island, and probably other volcanoes.