black ore metaultrabasite

Smerwick Harbour’s Black Ore

By Alan O’Connor

black ore metaultrabasite

The ‘black ore,’ metaultrabasite. The specimen is approximately the same size as a rugby ball. A 50-cent piece and a 30 centimetre ruler provide the scale reference.

Description

In the acquisition register of the National Museum of Ireland’s General Rock Collection, the entry for specimen NMING:R3931 reads:

“‘Ore’ of 16th century expedition to Baffin Island - see Hogarth 1989. 35 x 25 x 10 cm. Presented: Mr Donal O'Halloran. Metaultrabasite. Beach at Dún an Óir, Smerwick Harbour, Co. Kerry; collected and presented by Mr Donal O'Halloran. GE/34/1989; 19 June 1989.”

The specimen represents many things: The ancient Earth and the vastness of geological time; man’s greed, folly, and misfortune; the ability of scientific study to add to our knowledge of the past.

Background

In 1576, Sir Martin Frobisher set sail from England across the Atlantic Ocean in search of the Northwest Passage. He failed to find a route to the Pacific Ocean, but he did return from the Arctic with a souvenir: a large black rock.

In England, analyses of the rock returned conflicting results. Some determined that the rock contained high gold and silver content. Presented with the opportunity for vast wealth, further expeditions were planned to extract as much of the ore as possible. The second (1577) and third (1578) Frobisher voyages returned over 1400 tonnes of it back to Europe.

On the third voyage, the Emanuel of Bridgwater, captained by Richard Newton, trailed the rest of the fleet. Encountering rough weather off the west coast of Ireland, she found shelter in Smerwick Harbour, Co. Kerry. Badly damaged, most of her ore cargo was removed to the beach so that repairs could be carried out. A dispute over ownership of the cargo soon arose between Captain Newton and the local authority, Gerald Fitzgerald, 16th Earl of Desmond. Before the dispute was settled, it was conclusively proven that the ore brought back from the Canadian mines did not contain significant quantities of gold and silver; the ore was economically worthless. Captain Newton never reclaimed his cargo, and the Emanuel of Bridgwater was never made seaworthy again. Within a quarter of a century, all trace of the abandoned wreck had disappeared.

How did this specimen come to be in the museum?

In 1987, Professor Donald Hogarth of the University of Ottawa came to Ireland hoping to find what remained of the Emanuel of Bridgwater’s cargo. Searching Smerwick Harbour, he found several unusual black cobbles similar to the one pictured above. Radiometric dating determined that they were older than any other rock known to be found in Ireland. They were between 1900 and 1800 million years old, a period of the Earth’s history (approximately 30 times longer ago than the extinction of the dinosaurs) the only living creatures on Earth were bacteria. As well as that, analysis of the rock’s composition found distinctive similarities with known examples of the black ore retrieved from Frobisher’s mines on Baffin Island. Professor Hogarth’s analysis provided compelling evidence that the rocks he had found in Smerwick Harbour were a part of the precious cargo deposited by the Emanuel of Bridgwater over 400 years ago. In 1989, Mr Donal O’Halloran of Cork collected further examples of the ore and donated them to the museum.

Postscript

Shortly after the Emanuel of Bridgwater was abandoned, an old fortification in Smerwick Harbour was rebuilt. It is known as ‘Dún an Óir,’ meaning ‘fort of gold.’ The name may be an allusion to the once-precious cargo left behind over four centuries ago.

Learn more…

This specimen is part of the museum’s scientific collection, and is not on public display. A variety of geological specimens can be viewed in the Natural History Museum of Merrion Street, in cabinets flanking both the ground and first floor.

The information for this article was taken from the following sources:

Hoggarth, D.D. and Loop, J. (1986). Precious Metals in Martin Frobisher’s ‘Black Ores’ from Frobisher Bay, Northwest Territories. Canadian Mineralogist, vol. 24, pp 259-263.

Hogarth, D.D. (1989). The Emanuel of Bridgwater and Discovery of Martin Frobisher’s ‘Black Ore’ in Ireland. The American Neptune, vol. 54, No. 1, pp 14-20.

Hogarth, D.D. and Roddick, J.C. (1989). Discovery of Martin Frobisher's Baffin Island "ore" in Ireland. Canadian Journal of Earth Sciences, 26(5): 1053-1060.

 
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