FOREST UNDER SEA

Evening Post, Volume CIX, Issue 38, 14 February 1930, Page 4

FOREST UNDER SEA

AUCKLAND DISCOVERIES

PROOF OF SUNKEN COAST

Unmistakable traces of a buried forest, probably thousands of years old, have boen discovered recently in tho bed of tho Auckland Harbour, states tho "Now Zealand Herald." Massive roots of trees, obviously of great age, and a small picco of timber with a coating of soft stone, have been brought to the surfaco in the buckets of tho Harbour Board's dredge Hapai during dredging operations in St. Mary's Bay. They were recovered below 20ft of clay.

The discovery is of considerable interest, as it confirms the theory that the Waitemata, as indeed the, greater part of the Hauraki Gulf, with its innumerable, inlets and islands, is a sunken valley of not very great geological age. Fourteen years ago finds of a very similar character wero made during dredging operations in . Mechanics' Bay, i-id specimens of the timber then recovered are preaorved in tho Harbour Board's offices in Quay street. They were examined at the time by Professor J. A. Bartrum, of the Auckland University College, who commented upon the partially carbonised nature of tho wood, and the proBencß in tho concretions of fossilised crabs and molluscs of a contemporary species. "It is evident," he Wrote in a paper road before the Auckland Institute on 13th Decembor, 1916, "that these concretions not only aro contemporaneous with the beds in which they exist, but, further, have been formed at no very distant date."1

Tho comparatively recent subsidence of the harbour is a conclusion upon which all leading geologists are agreed. Professor P. Marshall, referring to the Auckland Isthmus in his "Geography of Now Zealand," says the inlets i with which it abounds "aro certainly drowned river valleys, 'and the absence of terraces round tho' shore . line proves that in,this northern district reclamation has not yet commenced." Professor Bartrum, in the paper referred to, writes: "The pertinent facts of. tho recent physiographic history of Auckland are that the Auckland Harbour represents a former stream-valley drowned by invasion of the sea within fairly recent geological times and that, subsequent to the drowning, the only recognisable movement of elevation (evidenced, by wave-cut platforms)'is one involving an uplift of not more than sft or 6ft."

It is clear, now that forest remains have been located one and a-half miles from the spot where they were first noticed in 1916, that many centuries ago the bod of the Waitemata was dry land—a valley heavily clothed in virgin bush with probably a river running into tho sea. Although showing signs of great age, the timber of the roots recovered by the Hapai from beneath the clay is in a good state of preservation, and there are several large logs covered with remnants of bark. The stone-covered piece of wood, already referred to, is visible at both ends of the stone covering, and at one time the wood must have been badly ravaged by toredo. It is similar in appearance to several specimens of timber concretions recovered from the bed of Mechanic's Bay. The concretions were dug out of tho thick bed of clay which has remained undisturbed beneath a layer of sea mud for ages.