CITY GEOLOGY

New Zealand Herald, Volume 79, Issue 24214, 4 March 1942, Page 2

CITY GEOLOGY

ALBERT PARK VOLCANO The excavations round the boundaries of Albert Park in preparation for tunnelling are of much interest because they reveal a little of the structure of the small volcano which once was active there. A civil engineer with an interest in geology yesterday expressed the opiuion that the fine volcanic tuff made visible near the Public Library had been the first matter ejected. He considered that the scorialike deposit forming the face at the head of Victoria Street had overflowed later in the form of a froth aerated by steam. Small masses of molten basaltic material had also been thrown up at intervals, and after falling had spread out to form grey pancakes an inch or two thick. These could now be seen embedded in the scoria. The engineer thought it remarkable that the tuff in the face in Wellesiey Street East formed a layer only abo.it 6ft. thick above a deposit of dark blue clay or pug, apparently formed under the sea. The tunnelling, he believed, would disclose other interesting things. The face which has been opened up in Victoria Quadrant by the removal of part of an old stone retaining wall is of scoria, rather similar to that seen in Victoria Street, but containing no email layers of Milestone.