Bell and Clarke. — Geological Reconnaissance of Northernmost N.Z. 617 



wackes, and contain veins of barren quartz. The Palaeozoic age is doubtful, 

 and it is probable that they are of more recent deposition. 



Marshall, who examined the area between Mangonui and Ahipara,* 

 maps the older rocks in that area as igneous, whereas McKayf considers 

 that both sedimentary and igneous rocks are represented. We think that 

 the older rocks on the coast-line north of Whangaroa Harbour, which Mar- 

 shall maps as igneous, contain representatives both of sedimentary and 

 igneous rocks. However, in consideration of Marshall's pronounced view, 

 the older rocks between Mangonui and Ahipara are shown as igneous on 

 the map accompanying this paper. 



About twelve miles north of Waipapakauri, on the west coast, the pro- 

 minent hill of Hukatere rises some 300 ft. above the surroimding sandy 

 waste. All outcrops on this hill are at present obscured by a covering of 

 ■drifted sand, but from its markedly greater elevation it seems probable 

 that it is composed of older rocks — possibly of the Mount Camel Series. 

 The outlying pierced island of Matapia may possibly be of the same nature. 



On the high land in the immediate neighbourhood of the North Cape 

 headland, according to McKay,| associated with the igneous rocks to be 

 presently described are " slates and sandstones," which he assigns to the 

 same age as the Mount Camel Series. 



Whangakea Series. 



The rocks which are tentatively placed under this series consist of 

 greenish and purplish indurated stratified rocks, possibly in part argiUites, 

 associated Math basic and semi-basic igneous rocks, probably both intru- 

 sive and contemporaneous. These rocks are either synchronous with or 

 later than the Mount Camel Series. 



The Whangakea Series is exposed along the northern coast-Hne between 

 Cape Maria van Diemen and the western (Whangakea) end of Spirits Bay. 

 At the latter place occur purplish and greyish apparently argillaceous rocks, 

 often much brecciated, and containing rounded lenses of harder material, 

 which give them a conglomeratic appearance. A microscopic examination 

 of these lenses shows that they are largely composed of comminuted frag- 

 ments of a basic igneous rock — whether plutonic or volcanic in origin is 

 not clear. In places definite igneous rocks appear in close association 

 with those just described, though, owing to the intense brecciation, it is 

 difficult to be sure whether they are contemporaneous with or intrusive 

 into the seemingly argillaceous strata. It is probable that the latter are 

 tufis. 



Rocks of even more nondescript character occupy the sea-front from 

 Cape Maria van Diemen to Spirits Bay. The pink-weathering sediment- 

 aries cut by basic plutonics near Kerr Point probably belong to the 

 Whangakea Series. 



McKay,§ on palaeontological grounds, considered the rocks of the 

 Whangakea Series to be Triassic. Hector, || however, thought that they 

 possibly belonged to the Maitai Series (Lower Carboniferous). We are 

 unable to offer fresh evidence on this important question, beyond saying 



* Trans. N.Z. Inst., xl, 1907, p. 82. 



t Rep. G.S., No. 22, 1894, map facing p. 80. 



X Rep. G.S., 1894, p. 89. 



§ Rep. G.S., 1894, p. 90. 



!! Rep. G.S., 1894, p. xix. 



