100 Transactions. 



(linionite), forming tough, resistant, anastomosing bands, or more fre- 

 quently lens-like or irregular beds of considerable thickness, which con- 

 stitute the most resistant parts of the nearly vertical cliffs, and in a few 

 cases, as at the Fishing Rock, opposite Waipipi, form reefs running a 

 short distance out to sea. 



From the general proximity of the watershed to the line of cliffs, and 

 the longer and more gentle easterly slope towards the Waiuku Creek, and 

 from the loftiness of the cliffs, which have been cut back by the waves 

 almost to the watershed, and the character of some of the lower beds, it 

 is evident that these hills at one time extended much farther seaward — 

 probably several miles at least. Except in the extreme south of this area 

 the sand of these hills is much limonitized and consolidated, while the 

 surface on the easterly (or landward) slope is decomposed to a yellowish-red 

 clay to a depth often of 6 ft., and is covered with a fairly good soil. 

 . Near the Waikato River and the " gaps " or stream- valleys opening 

 west the surface is composed of loose sand travelling inland. This is 

 particularly well shown at Lake Pokorua. Only in a few places, such as 

 the Waiuku and Pokorua gaps, is there convenient access to the beach. 



A mile south of Pokorua Stream outlet a bed of lignite outcrops for a 

 distance of 100 ft. at the foot of the cliffs. It is about 5 ft. above high 

 water, but rises gently to the south. The only other bed of lignite out- 

 cropping on the coast is a small one in a short stream-valley two miles 

 south of Manukau Heads. The only other lithologic feature deserving of 

 mention is a bed of sand from 3 ft. to 6 ft. thick, near the foot of the cliffs 

 close to the outcrop of lignite, which is a fine, light, white sand, evidently 

 pumiceous. 



The Area East of the Sand-dunes. 



To the east of the sand-dune range, bands of lignite 18 in. thick can 

 be seen on both sides of Waiuku Creek, just above or at high-water mark 

 Beds which are either pumiceous or of very fine light sandstone occur above 

 the lignite. On the east bank a coarse conglomerate sometimes occurs. 

 A short distance to the north of Awhitu Wharf a bed of lignite occurs 

 intercalated in sand. Stream-bedding is noticeable in most of these deposits 

 of sand along the Waiuku Creek. 



Hochstetter (1867, p. 272) furnishes a section which seems too general- 

 ized in respect of the lignite formation. The occurrence of but two small 

 bands, the larger not more than 100 ft. long, in a length of sea-cliff 

 extending twenty miles hardly warrants the use of the name " lignite 

 formation " to include the western lower beds on the coast range in which 

 these two bands ocour. Their very frequent occurrence in the sand and 

 silt-beds along the Waiuku Creek, however, amply justifies the name so 

 far as it is applied to the low-lying area east of the coast range. The 

 undulating country east of Waiuku Creek and of the Akaaka Swamp 

 consists of an extensive deposit of basaltic breccia — the " basaltic boulder 

 formation " of Hochstetter (1867, p. 268), Hutton (1867, p. 7), and Cox 

 (1877, p. 17) — mixed with much red loam resulting from decomposition 

 of the breccias and tuffs. 



The most extensive lava-flow is that at Waitangi Stream, two miles 

 from Waiuku ; whilst the volcanic tuffs become very prominent in the 

 Koraka district, near Drury. On the south side of the Waikato River, 

 at Pakau Stream, and at Tauranganui, three miles to the north-east, lava- 

 flows occur associated with volcanic breccia similar to that forming several 

 small isolated hills in the Akaaka Swamp. Evidence of stream-bedding 

 has been observed in the tuffs and breccia at Tauranganui. 



