Overview
Sun. Oct. 12.
Fine day with passing clouds. Left on bike after breakfast at 7.10. Reached Makotukutuku – Ngahape Road intersection at 7.30 + continued along unformed portion of former to the Porangahau Road. Crossed flood-plain of Ngahape Stream which flows in meanders in a channel about 12ft. deep. The surface of the flood-plain consists of alternating low ridges + damp hollows trending north-east north-east which is a direction parallel to the present courses of the Ngahape + Makotukutuku Streams to the southern end of Hatuma Lake. The flood plain was evidently built up there by these two streams the low ridges on it being their successive raised courses. The building up of this alluvial deposit caused the obstruction of the then deserted former valley of the Tukituki River + the impounding of the minor streams draining the eastern slopes of the southern part of the Turiri Range resulted in the formation of Hatuma Lake. At the present time the southern end of Hatuma Lake is bordered by extensive swamps with a network of lagoons + the drainage is very indeterminate. The outlet of
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the lake is also at its southern end not far from the entry of the Ngahape Stm [Stream] + this is another fact supporting the above theory of its origin. Reached the road leading to Porangahau at 8.5 near the Ashington homestead + turned north towards Waipukurau. The Punangiangi Stm. is very incorrectly marked on the county 1 inch map + I corrected this as far as possible. The outlet stream of Hatuma Lake is crossed by the road further out – it is fairly large + flows in meanders in a shallow channel. Beyond the bridge the road skirts the eastern foot of a low ridge of old gravels, composed of greywacke and thus an old deposit of the Tukituki washed down from the Ruahines. The mode of formation of these old gravels is not clear to me. From the top of the ridge I took a ½pl[ate]. photo (11) of the southern end of Hatuma Lake, the adjacent swamp + lagoons, the Ngahape-Makotukutuku flood-plain + the Turiri Range in distance. At this point the gravel ridge is almost 50ft above the edge of the Punangiangi flood-plain – at the junction of the Waipukurau Racecourse Road + the Porangahau Road there is a gap – then the ridge rise to a height of 80 or 100ft. + extends to the centre of Waipukurau. In the gravel-pit alongside the road north of the gap good sections of the old (brown-coloured) gravels
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can be seen. Met some little boys here + they told me what they knew about the district. The Porangahau Road runs along the crest of the gravel ridge as far as the boundary of Waipuk[arau] Boroughs. From here I took a road to the right and cycled past the old Tavistock Hotel (now the Devonshire boarding-house) at 9.30 + along the road which follows the Tukituki downstream. The high-level river terrace is here bounded on its outer (southern) margin by a low steep bank of chalk marls, above which there is a low undulating ridge dividing the present valley of the Tukituki from the Ngatoro Swamp, the site of its former course after leaving the present Hatuma Lake. In a roadside cutting the chalk marls are broken up into rubbly pieces up to 2 inches in length – this is probably due to decomposition in situ but may be transported material, wash from the higher parts of the outcrop. Turned back to Waipukarau at this point. The north end of the ridge of old gravel situated in the centre of Waipuk. has evidently been truncated by Tukituki river when it was flowing in its present course on its high-level terrace. Went up the Race-course Road a short distance + then took the Takapau Road which runs up the high-level terrace
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of the Tukituki towards the watergap. West of the junction of Hatuma Road there are 3 or 4 individually low but still higher-level terraces bounded on their southern side by a low hilly ridge. I suspect that, on examination, this hilly ridge + also the terrace-like ridge on which Mt [Mount] Vernon homestead is situated, will prove to be composed [of] old gravels identical to the Waipuk. ridge. A cutting in the sharp bend in the road (10.30am) as the laminated (cross-bedded) sands overlain (here as before noted elsewhere) by the Te Aute Limestone of the Turiri Ridge. Took a 1/2pl. photo (12) of the Tukituki watergap. Near the top of the limestone ridge, road-cuttings furnish good sections: the limestone is cream coloured + is composed of shell + coral fragments broken rather fine. On the end of the ridge and facing into the water-gap is the slump topography previously noted; on the eastern side there is a trench without outlet + a protruding mass, + on western side a succession of hammocks leads down to Onga Onga Road. The large sanatorium for consumptive returned soldiers crowns the crest of the ridge overlooking the water-gap. Cycled down to the edge of the Ruataniwha Plain + leaving bike examined the cliffs of the truncated spurs
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of the western slope of Turiri Range. These cliffs consist of papa, blue below + yellow above, + contain bands of fossil shells, mostly the small oyster but also pectin, Magellanea-like bivalves, coral fragments etc. I found a cast of a very large bivalve, 5 inches in length. Some of the molluscs had barnacles attached. The truncation of these spurs was effected by the Makeretu [Makaretu] River which is still undercutting them just above the ferro-concrete Onga Onga Bridge. The upper yellow paper contained oysters, 2 varieties of coral, the Magellania-like bivalves with barnacles, tubes etc. – between it the blue papa was a layer of nodular concretions (calcareous lime, they effervesce strongly under hydrochloric acid) – these are brownish externally and light grey inside + in size range up to several inches in diameter. The Makaretu joins the Tukituki half a mile below Onga[Onga] Bridge – the ends of the long flat-topped spurs from Mt Vernon are truncated from the junction for a distance of about one mile northwards. Took a 1/4pl. photo (13) from the top of truncated spur showing Makeretu River with its broad shingly beds + branching channels in foreground + Oruawharo + Takapau-Rangitoto Ridges in distance, also truncated spur-ends on left. The prominent truncated spur-ends extend for 1 ½ miles south from the Onga Onga Bridge – this is probably
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the range of truncation by the Makeretu. For the next 2 ½ miles, i.e. as far as Marakeke railway station, the truncated spurs are less pronounced and on this stretch were the work of lateral swinging by the Maharakeke Stm. South of Marakeke the spurs slope down to the level of the Ruataniwha Plain which has here a cut surface ([illegible]) which grades into the “built” (gravelly) surface further west. From the line of truncated spurs there is a distinct slope westward to the main part of the Plain – this slope is a series of recent fans deposited by the small backslope streams of the Turiri Range since the truncation took place. Home at 1.10pm. Changed + dined. Later in pm sketched up plan of homestead, pacing distances + guessing angles. In evening read Oliver Goldsmith’s “Deserted Village” + Gray’s “Elegy”, fine stuff.