312 The N.Z. Journal of Science and Technology. [Jan. 
A period of uplift followed, accompanied by faulting, by the extrusion 
of volcanic rocks of intermediate composition, and by erosion which wore 
down these soft sediments to a nearly plane surface. After an interval 
another depression ‘ allowed the accumulation of the conglomerates, grits, 
coal, sandstones, limestones, and claystones of the Whangarei formation. 
These deposits were then uplifted, and have been exposed to subaerial 
denudation from Pliocene times until the present day, except where covered 
and protected by basaltic lava-flows erupted during the Pliocene and 
Pleistocene periods. 
The Stratigraphical Succession. 
The following table sets out the above sequence of events, and includes 
a tentative attempt to correlate the deposits of North Auckland with the 
Notocene succession in other parts of New Zealand, as well as with their 
probable homotaxial equivalents in Europe. 
Local Name. 
Description of Strata. 
Series or System. 
Approximate 
Age. 
Swamps, alluvium, wind-blown sands 
• • 
Recent. 
Purua beds, 50 ft. 
Gravels, carbonaceous sandstone, 
sands, fresh-water leaf-beds 
Pleistocene. 
Period of block - faulting : erosion ; 
extrusion of rhyolitic tuffs and 
basic lavas 
Pliocene. 
Whangarei forma¬ 
tion, 1,000 ft. 
Grey claystones or calcareous sand¬ 
stones 
Calcareous claystones and arenaceous 
limestone, 300 ft. 
Crystalline or Whangarei limestone, 
130 ft. to 250 ft. 
Glauconitic and argillaceous sand¬ 
stone, 300 ft. to 500 ft. 
Conglomerate, grit, &c., with coal, 
50 ft. to 100 ft. 
'X 
)> Oamaruian 
J 
Miocene and 
Oligocene. 
Erosional interval: fracturing of 
strata,; extrusion of volcanic rocks 
of intermediate composition 
Eocene. 
Onerahi forma- 
tion, 1,500 ft. 
r 
; 
Impure limestones, claystones, or 
greensands 
Flint-beds of Hukerenui and hydrau¬ 
lic or Mahurangi limestone 
Greensand, grit, and conglomerate 
1 
S-Waiparan 
J 
Cretaceous. 
Post-Jurassic orogenic movements: 
erosion. 
Waipapa formation, 
16,000 ft. 
Argillites, greywackes, sandstones, 
quartzites, and minor limestones 
Hokanuian 
Trias-Jura. 
Kerikeri series 
Wairakau series .. 
Igneous Rocks. 
Rhyolitic tuffs, basalts, and scoria- 
cones 
Andesitic agglomerates and andesites 
Pliocene- 
Recent. 
Eocene- 
Miocene. 
The order of succession shown by the above table differs from the order 
adhered to by Hector and McKay chiefly in placing the hydraulic limestone 
below the coal-measures instead of above them. It approximates to the 
succession suggested by Cox, who placed the Whangarei limestone above 
