Overview
Fri. Oct. 10.
June morning but too dull for photos. After breakfast walked round with Mr. Herd – he is stocked with breeding cows + calves, ewes + lambs + hoggets. Owing to bad spring he has lost a large number of the last. At 10.am Mrs Herd, Maud, Clyde, Nancy + I set out in trap to visit Frank Goulding at his little farm in the Lindsay Settlement beyond Waipukurau. The northern extension of the Turiri Range, as noted before, has a double crest – two steep scarps + a gentler backslope, the shelly limestone forming the cap of each ridge. The dip of the limestone layers in the small quarry at
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the junction of the Makotukutuku + Rangitoto Roads is 23°. Passed through Hatuma (which consists of a store-post office, a school, rly. Stn [railway station] + rly-men's cottages) + then took the Hatuma– Waipuk[erau]. road. The lowest shore of Hatuma Lake is at its south east corner + this is the probable position of its outlet. At its north end the low high-level terraces of the Tukituki slope laterally (with respect to the present course of the river) down to the margin of the lake. A gravel-pit opened in these high-level terraces shows fairly fine brown gravels, some layers of which are current-bedded. Since my visit about 6 years ago, Waipukurau has grown very much larger + is now very prosperous looking. We crossed the Tukituki Bridge + turned up the Waipawa Mate Road which runs along the top of a high level terrace (of brown gravels) corresponding to the one on the right bank of the river. Passed M[oun]t Vernon homestead which is well situated on still higher terraces at the foot of spurs running south from Mt Vernon trig. 1010´. Arrived at Frank’s section at 11.45am – it is situated in an angle of the road which divides it from a long flat-topped steep-sided limestone ridge (corresponding to Turiri Range). The section is practically flat + has a 4-roomed whare with
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garden, orchard + shelter-belt + numerous outbuildings. While dinner was in preparation, I ascended the limestone ridge above the Waipawa Mate Road + took a 1/2pl[ate]. photo (1) of the Tukituki River + its left-bank high level terrace with the Turiri Range in background. Frank’s farm in foreground. A magnificent panoramic view of Hatuma Lake + Waipukurau is obtained from the crest of the limestone ridge above Waipawa Mate Road but the day was too dull to photograph. Looking north from this ridge crest one sees two other flat topped ridges trending west from the vicinity of Mt Vernon trig. 1010´, which with two other similar prominences forms a higher north-south trending ridge, the descending southern end of which terminates at Mt Vernon homestead. The Turiri Range ends at the Tukituki watergap, but the same geol[ogical] structure is continued in the Mt Vernon trig + its radiating ridges, the trend of which differs from that of the Turiri Range solely on account of different development of the drainage, streams having a “subsequent” direction being absent. The outlines of McKay’s section of Mt Vernon is very generalized but the geol structure shown is probably correct. After dinner Frank + I walked round his farm. The soil is fairly rich having originated as a series
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of small coalescing alluvial fans – silt washed from the nearby limestone ridge by tiny streams. At the east end of the farm the alluvium was depositied as the raised flood-plain of a much larger stream rising in Mt Vernon + which formerly had a meandering course but which has now been diverted by an artificial drain running alongside the Waipawa Mate Road. All these alluvial deposits rest on the surface of the high-level terrace of the Tukituki. Near the river this terrace is composed of gravel but at the foot of the limestone ridge, it seems to have a “cut” surface. The silt fans + raised floodplain alluvium as only a few feet in thickness – in the drain alongside road I noted: 1ft. of black soil. 18 in[che]s of alluvium, on a “cut” limestone surface. This cut surface may however be the work of the stream from Mt Vernon, as its raised floodplain lies in a wide shallow trench cut across the Tukituki high-level terrace. Frank pointed out some old Maori trenches near corner of W[aipawa Mate]. Road just east of his farm. Took 1/4pl. photo (2) of Frank’s whare and visitors. We left for home at 2.30. Renewing my observations of the topography between Hatuma Lake + the Tukituki. I conceived the idea that the lake must lie in a former course of the river, for these reasons: The unin-
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terrupted slope from the high-level river-terrace to the north-end of the lake; the elongated shape of the lake; + the fact that its outlet must be situated somewhere at its southern end. The leading questions raised are: What caused the river to adopt its present course? What is the nature of the obstruction which impounded the drainage to form the lake? The origin of the gap in the western ridge of the Turiri Range at the junction of Rangitoto + Makotukutuku Roads is another phys. Problem. Two possible solutions. The stream (a tiny shrunken misfit) at present rising in the gap flows into Maharakeke. When it formerly flowed down the backslope of the western Turiri monochiral ridge, the ridge must have been higher + its strike scarp must further east. Either the stream-gully cut on the backslope has been beheaded by the recession of the scarp; or, the backslope stream had a “subsequent” headwaters east of the strike scarp + this “subsequent” portion was captured by the head of the Makotukutuku Stream, itself, it its upper egurac, a “subsequent” working on weaker strata than the limestone of the monochiral ridge, + further, draining to a lower base-level than the Maharakeke, reg Hatuma L[ake]. Home at 5pm. Took 1/2pl. photo (3) of the backslope of the western Turiri monochiral ridge looking north
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from Mr Herd’s farm. In evening played chess with Mr Herd + got quite fascinated with the game.