On the Coal-formation at Auckland, New Zealand

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Abstract
T he district is formed of stratified sandy clays, of Tertiary age; they vary in colour from white to light-red. The white clays contain beds of lignite, varying from a few inches to several feet in thickness. Sections of these beds are exposed along the banks of most of the tidal inlets with which the district abounds. In some places, near the hills, the lignite is seen to rest on trap-rock; elsewhere a shelly gravel underlies it. At Campbell’s farm a whitish sandstone lies on the lignite, and at the junction is hardened, and contains ironstone-nodules; these, when broken, yield remains of exogenous plants. A fossil resin is found abundantly in the lignite. On Farmer’s Land the lignite is 16 feet thick, including a little shale; at Campbell’s it is 7 feet thick, but thins away. There is some iron-pyrites in the lignite, but not sufficient to deteriorate its value as a coal. Similar coal has been found at Muddy Creek to the S.W.; at Mokau, about 100 miles to the south; and near New Plymouth. The Tertiary beds of Auckland are everywhere broken through by extinct volcanos, varying from 200 to 800 feet in height. The craters are generally scoriaceous, in a perfect condition, with a depression of the rim usually to the north or east. There are also around the district other volcanic hills, rounded, scoriaceous, more fertile than the crateriform hills, and apparently of an older date.

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