398 Transactions. 



Tlie beds of sandstone and clay with interbedded volcanic grits exposed 

 round the shores of the Waitemata Harbour have been known since the 

 days of Hochstetter as the Waitemata series. 



The Waitemata series is unconformably overlain by the lava-flows and 

 fragmental volcanic material from the volcanic vents of the Auckland 

 Isthmus, and at Panmure by later sedimentary deposits. 



All observers appear to agree that between Maraetai and Turanga 

 Creek rocks belonging to the Papakura series are represented, while the 

 sedimentaries between Turanga Creek and Auckland are mianimously called 

 Waitematas. Near Turanga Creek, therefore, the coiitact between the two 

 series, if they are distinct, must occur. 



Cox, in a paper " On certain Points Connected with the Geology of 

 the Auckland District,"* gives a section from Maraetai to Tamaki West, 

 in which he shows the " Maitai slates " overlain by the following sequence 

 of rocks : " (6) Calcareous sandstone, (c) clay marls, {d) concretionary 

 tufaceous sandstone, (e) clay marls, (/) concretionary tufaceous sandstone, 

 {g) bedded sandstones and clay marls, {h) plastic clays and sands." He 

 says that either a direct sequence occurs from (6) to the Orakei Bay beds, 

 with a possible miconformity between (d) or (/) and the Howick beds — 

 presumably (e), {g), or (h) — or else that the beds forming Howick Penin- 

 sula are luiconformably yomiger than both {d) or {e) and than the beds 

 found between Tamaki West Head and Orakei Bay. While he regarded 

 the latter view as the more probable, he considered that stratigraphical 

 evidence favoured the former view. Hutton's views have already been 

 summarized. Park (with whom McKay f agrees in this matter) in two 

 papersf affirms the conformity of the Waitemata and Papakura series 

 east of HoMdck, considering that the irregular overlap taken as evidence 

 of unconformity by Hutton and Cox was due to unequal erosion of hard 

 and soft beds. 



In his paper on " The Volcanic Beds of the Waitemata Series " Fox§ 

 remarks (p. 485) that from the Papakura limestone to the liighest Waite- 

 mata sandstones the series apparently has no break. 



The evidence for miconformity between the Waitematas and the Papa- 

 kuras appears to depend on (1) the relation between the series as seen near 

 Turanga Creek ; (2) the relation between the series as seen in the cliffs 

 between Howick and Maraetai. 



As regards (1), the Avriter has followed the sequence from the so-called 

 Turanga greensands (which are volcanic grits) ]| which Hutton regards 

 as part of the Papakura series to the undoubted Waitematas at Howick, 

 and after mapping all the observed strikes and dipslj can find no evidence 

 of unconformity. 



As regards (2), passing along the shore-line from Motu Karaka towards 

 Maraetai, alternating sandstones and clays, in places dipping steeply, in 

 others almost horizontal, are seen to be quite unconformably overlain near 

 the top of the low cliffs by a soft clay showing little or no bedding. In 

 the upper part of this clay is a well-defined horizontal seam, about 6 in. 



* Rep. Geol. Surv., during 1881. 

 t Rep. Geol. Surv., during 1887-88, p. 40. 



t Rep. Geol. Surv., during 1885, p. 136, and Trans. N.Z. Inst., vol. 22, p. 301. 

 § Trans. N.Z. Inst., vol. 34, p. 485. 

 II Fox : Trans. N.Z. Inst., vol. 34, p. 485. 

 Tf Too numerous to place on the rough sketch-map accompanying this paper. 



