114 Transactions. 



be considered a Globigerina ooze. In the section examined there were, in 

 addition, other foraminiferal remains, and an echinoid spine, together with 

 some grains of iron-pyrites. (Plate XX, fig. 3.) 



Summary and Conclusions. 



South of the Waikato River occurs a folded older-mass of Mesozoic age, 

 on the broadly truncated erosion-surface of which was laid down a younger- 

 mass of Tertiary strata showing unconformity, or at least discontinuity 

 of deposition between some series, as at the Kawa. 



North of the Waikato River is an area of younger (Quaternary) sedi- 

 mentary strata with a fine of elevated sand-dunes fronting the coast. 



Along lines of major dislocation coincident with the northern limit of 

 the Manukau Harbour in one case, and, in the other, with the fine of the 

 lower Waikato River, considerable differential movements resulted in uplift 

 of the areas to the north and south relatively to the middle (or Manukau) 

 area. The latest considerable movement of the southern area appears to 

 have been uplift to the approximate height of 180 ft., and to have occurred 

 since the Waikato River began to discharge itself by its present outlet.* 

 Minor oscillations have occurred in sub-recent times, especially in the middle 

 area. 



The Manukau sand-dune range originated in a spit or barrier beach 

 which created a broad estuary of the Waikato River. 



The Manukau Harbour owes its origin to streams, during minor uplift, 

 cutting into the silts deposited in the former Waikato estuary, whilst 

 subsequently the area subsided slightly, allowing the sea to penetrate into 

 these stream-courses and rapidly push back the low sea-cliffs cut in the 

 unconsolidated silts 



The ages of the Tertiary strata and the importance of the physical uncon- 

 formity and strati graphical discontinuity in the Kawa beds cannot be 

 decided definitely without further palaeontological evidence, which it is 

 hoped will be available in the near future. 



References. 



Arber, E. A. Newell, 1917. The Earlier Mesozoic Floras of New Zealand, N.Z. 



Geol. Surv. Pal. Bull. No. 6 (n.s.). 

 Bartrxtm, J. A., 1917. Additional Facts concerning the Distribution of Igneous Rocks 



in New Zealand, Trans. N.Z. Inst., vol. 49, pp. 418-24. 



1919a. New Fossil Mollusca, Trans. N.Z. Inst., vol. 51, pp. 96-100. 



1919b. A Fossiliferous Bed at Kawa Creek, West Coast, South of Waikato 



River, New Zealand, Trans. N.Z. Inst., vol. 51, pp. 101-6. 

 Cox, S. Herbert, 1877. Report on Waikato District, Rep. Geol. Explor. during 1876-77, 



pp. 16-25. 

 Cussen, L., 1889. Notes on the Waikato River Basin, Trans. N.Z. Inst., vol. 21, 



pp. 409-10. 

 1894. Notes on the Piako and Waikato River Basins, Trans. N.Z. Inst., vol. 26, 



pp. 400-1. 

 Hector, J., 1877. Progress Report, Rep. Geol. Explor. during 1876-77, pp. 7-8. 

 Henderson, J., 1918. Notes on the Waikato Valley, near Maungatautari, N.Z. Jour. 



Sci. & Tech., vol. 1, pp. 56-60. 

 Hutton, F. W., 1867. Geology of the Lower Waikato District, Rep. Geol. Explor. 



during 1867, pp. 1-8. 

 Hochstetter, F. von, 1867. New Zealand. 

 Park, J., 1910. Geology of New Zealand. 

 Thomson, J. A., 1917. Diastrophic and other Considerations in Classification and 



Correlation, and the Existence of Minor Diastrophic Districts in the Notocene, 



Trans. N.Z. Inst., vol. 49, pp. 397-413. 



* This estimate is based upon the data furnished by the pumice-bed in the section 

 exposed south of Kawa Stream. 



