CEAwroED. — Geology of the North Island of New Zealand. 321 



between "Wellington and Napier. In Palliser Bay the cliffs are from 50 to 

 150 feet high, composed of " drift " gravel on the western side, of gravel 

 over blue clay on the eastern. Passing across Palliser Bay we arrive at the 

 highly inclined rocks of the main range, cut off and scarped along this south 

 coast, and at the Mukamuka are found trappean rocks, altering the slates 

 into jasperoid rocks. At this point also was the greatest rise of land caused 

 by the earthquake of 1855 (viz. 9 feet), and here the coast road, which was 

 before that time almost impassable except at low tide, has now a broad 

 stretch of rocky beach between it and the sea. 



Proceeding to the Avestward along the south end of the island, we con- 

 tinue to pass the vertical scarp of the rocks caused by the great depression 

 of Cook Strait ; the strata being highly inclined, and the mountains forming 

 remarkably sharp ridges, rising to a height of from 2,000 to 3,000 feet, 

 and running in a N.N.E. direction. Looking up the noble harbour of Port 

 IS'icholson, the alluvial valley of the Hutt may be perceived, forming the 

 only great longitudinal valley of the mountain ranges. Proceeding onwards 

 we may find the same evidence of the intrusion of igneous rocks as at the 

 Mukamuka, and may also perceive small patches of drift gravel lying at 

 various elevations from 400 feet dowuAvards. Prom the position of these 

 terraces we may, I think, conclude that they were formed previous to the 

 depression which formed Cook Strait. At Terawiti, instead of passing along 

 the great scarp at right angles to the strike of the rocks, we now proceed to 

 the northward in their line of direction, and as we look into the harbour of 

 Porirua we may think of the "plant beds" there, a further investigation of 

 which may perhaps lead to a clear history of the age of these rocks. On 

 the left we leave the flat-topped island of Mana (palaeozoic), and pass on to 

 the junction of the tertiary and palseozoic rocks near Paikakariki, and here the 

 great tertiary basin commences. Prom this point the ranges of the old rocks 

 pass away inland towards the N.N.E., while the tertiaries, commencing the 

 great western curve towards Cape Egmont, are as yet only represented 

 by dunes of sand. Eight miles further on we reach Waikanae, opposite to 

 which is the high palseozoic island of Kapiti, which forms a shelter from the 

 prevailing westerly winds. In consequence of this protection the "Waikanae 

 E-iver throws out a long point seaward. At Otaki, in addition to the sandy 

 dunes, there is a considerable breadth of " drift" gravel formation, and also 

 here and along this coast there is much alluvium and swamp. At the Mana- 

 watu Eiver, the sandhills, which sometimes reach a height of from 40 to 50 

 feet, attain their greatest breadth, of about ten miles, and are intermixed with 

 some rich tracts of swamp and alluvium. Inland of this the " drift " gravel 

 forms terraces, and what appears to be the blue clay shows itself a few feet 

 above the river level, the mountains having receded to a distance of 25 or 

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