(1841–1917).

Geologist.

A new biography of McKay, Alexander appears in the Dictionary of New Zealand Biography on this site.

Alexander McKay was born on 11 April 1841 in the village of Carsphairn in northern Galloway in south-west Scotland. He came from Calvinistic shepherd stock, though his father, William Sloane McKay, was a joiner and wheelwright. He attended school until 11 years of age, after which he became a cowherd during the summer and, when not helping his father, attended school during the winter. At an early age he realised the significance of stratification in rocks and prospected for lead ores in the Rhinns of Kells Range. Departing from Glasgow on 3 July 1863 in the Helenslea, he landed at Bluff. After goldmining in Otago and in the Wakamarina Valley, Marlborough Province, he went to Australia and worked on the New South Wales and Queensland diggings, returning to New Zealand in 1866. For the next four years he was prospecting in the south-west part of the Mackenzie Country, where he met Canterbury's Provincial Geologist, Julius von Haast. Haast engaged him as an assistant in 1870, and in 1871 employed him to collect, for the Canterbury Museum, fossils from the saurian beds in the Waipara River. In 1872, with the assistance of McKay, Haast excavated the Sumner Cave near Christchurch.

McKay was appointed Fossil Collector to the Geological Survey of New Zealand in 1873, was promoted to Field Geologist in 1876, to Assistant Government Geologist in 1885, and became Mining Geologist to the Mines Department in 1892. Subsequently he became Government Geologist and kept this post until his retirement from the Public Service in 1906. He died in Kelburn, Wellington, on 8 July 1917.

In the course of his field work McKay covered nearly the whole of New Zealand, and his papers in Reports of Geological Explorations, VIII-XXII, are still basic sources of information. Where later geologists have argued, McKay's original reports generally have survived critical examination. As a field geologist he was careful not to suppress observations discordant with theory. For example, in his report on the 1888 Glenwye Earthquake, he observed that two fence lines were horizontally offset by 8 and 9 ft, an observation not in accord with the concept of purely vertical faulting held by geologists at that time. Only during the last 20 years has the concept of horizontal fault movement become accepted universally, and McKay was therefore almost certainly the first geologist in the world to have recorded such lateral displacement.

His outstanding contribution to New Zealand geology lies in the field of structural geology. During his 1884–85 and 1888–89 explorations in the Middle Clarence and Awatere valleys, he found the “Cretaceo-Tertiary” rocks resting on the much older greywackes of the Kaikoura Ranges, and bounded on one side by long faults. McKay concluded that the Kaikoura Ranges did not exist when the younger rocks were deposited and that these ranges were of relatively young (post-Miocene) date. Subsequently he extended this theory of mountain building by block faulting to other parts of New Zealand, notably Central Otago. His work received little attention at the time, but is now accepted as substantially correct. Another of McKay's theories, only recently revived, concerns the origin of the serpentine and dunite rocks forming the well known “Mineral Belts” of Nelson and Otago. McKay considered these rocks to be altered submarine lavas, a view now widely supported by New Zealand geologists.

His lasting contributions to New Zealand geology have been commemorated by the Geological Society of New Zealand in the establishment of the McKay Hammer Award for the best annual publication on New Zealand geology.

McKay married twice: first, at Dunedin in 1868, to Susannah Barnes; and, secondly, at Wellington in 1907, to Adelaide Doutson. He had two sons by his first marriage.

(NOTE – Alexander McKay, geologist, is sometimes confused with Alexander Mackay, a surveyor and explorer in Nelson and Westland.)

by Geert Jan Lensen, New Zealand Geological Survey, Lower Hutt.

• Alexander McKay's Memoirs (MS), Turnbull Library
• Memoirs of James Park (MS), Hocken Library
• Transactions of Royal Society of New Zealand, Vol. 50 (1918), (Obit).