Shubenacadie River Titanium

The world’s highest tides helped create a huge titanium deposit, but they have also made extracting the titanium, which is used in clean energy and many other industries, a significant challenge.

Sand bars in the Shubenacadie River have been known for centuries to be mineral-rich. Acadian settlers saw them as a potential source of iron. However, the main mineral in the sands is ilmenite, which contains both iron and titanium, but which was not considered a high-quality source for iron at the time.

Centuries later, modern mineral exploration has given us a much better understanding of the sand bars and their mineral potential.

In 1972, a company called Glooscap Minerals found titanium-bearing minerals in the Shubenacadie River.

Samples collected by the province’s Department of Mines in 1987 were examined by the Atlantic Coal Institute, which found that “concentrations of TiO2 [titanium dioxide] in the River bed sand reached over 22%... These initial, promising results justify further work at this location and others along the River bed and areas in the Cobequid Bay displaying heavy mineral sands concentration.”

Perhaps most interestingly, in 1990, the United States Geological Survey published a paper about a deposit of fine-grained rutile, a titanium-bearing mineral, in the Gulf of Maine, directly down-current from Cobequid Bay and the Bay of Fundy. The report concluded that much of the rutile came from Nova Scotia and New Brunswick.

Titanium Corporation of Canada, which later became NAR Resources Ltd., explored part of the Shubenacadie River in the late 1990s and discovered that it contained a world-class titanium deposit - over 330 million tonnes of mineral sands grading an average of 1.94% heavy minerals, mostly the titanium-bearing minerals ilmenite, rutile and leucoxene.

These figures are considered conservative because NAR’s exploration drilling program only went to a maximum of about 5 metres deep and the sand bars are known to be deeper, as much as 25 metres deep in some cases. Also, additional sand bars that were not explored have potential to significantly increase the tonnage.

The sands were also found to contain recoverable amounts of zircon and garnet, and subsequent exploration has shown that the sand bars also have potential for rare earth elements, which are critical minerals used in wind turbines, electric vehicle engines and electronics.

Seen from a distance, some of the sand bars can have a reddish colour due to their iron content, which oxidizes (rusts) when exposed to oxygen. Up close, however, the heavy minerals make the sands look black and dirty.

The geological origin of the titanium is not known but it likely came from more than one source, including erosion of the North Mountain, the Cobequid Highlands and the sedimentary rocks that immediately underlie the river and surrounding area.

Nature has done much of the work necessary to mine and process the titanium. Most mines and quarries extract large rocks and then crush them to produce small rocks that can be sorted and/or further processed to extract minerals from them. The Shubenacadie River titanium deposit has already undergone much of this process naturally.

Erosion broke down large rock from the North Mountain and other locations. Water and other geological forces carried the eroded rock along, breaking it down further to sand-sized particles. And the Bay of Fund’s extraordinary tides have concentrated the heavy, mineral-rich sands into world-class deposits by moving them back and forth in the Shubenacadie River for eons and causing the heavy minerals to settle out together.

If extracted, the tides could also play an important role in naturally reclaiming the sand bars by constantly bringing in new sand and continuing to organize it, effectively returning the bars to their original state.

Another advantage of the tides is that their energy keeps the Shubenacadie River at its maximum sediment load, so any clouding produced by sand extraction would not muddy the water any further. In other words, the river water is always muddy because so much sand and sediment float in it, so stirring up the sediment would not cause any harm.

On the other hand, the extreme tides create significant challenges, and any extraction operation would have to find engineering solutions, just as tidal energy companies are trying to find viable ways to generate energy in the Bay of Fundy.

The Shubenacadie River is tidal for well over half its length – for about 48 kilometres - due to the Bay of Fundy’s tides and the fact that the river passes over an extensive lowland. Remarkably, a tidal change of as much eight metres occurs 34 kilometres upstream from the river’s mouth.

At low tide, over 80% of the river’s sand bars are exposed. At high tide, they become submerged to depths ranging from 3-5 feet. The incoming tide comes in the form of a wave (tidal bore) measuring up to five feet in height.

NAR’s plan, which was never implemented, was to vacuum up the sands using a dredge and use a gravity processing system to separate the mineral sands, which are heavier, from the other sands. The minerals would then have been taken to a processing plant onshore.

There would have been no chemicals used in the process because nature has already broken down and separated the minerals from their host rock.

NAR’s plan, written in 1998, would have returned the vast majority of the sand (i.e. well over 90%) to the river where the tides would have quickly returned the sand bars to their original condition.

The approach NAR proposed was consistent with how most titanium was extracted then and still is today: “Titanium minerals are most often extracted from heavy mineral sands using dredging or dry mining techniques,” the United States Geological Survey wrote in 2018.

Titanium has a wide range of uses and it is considered a critical mineral now because it is as strong as steel but half as heavy, and it is resistant to heat and corrosion. This makes it particularly important in renewable geothermal energy. Underground geothermal water reservoirs, from which we take hot water to produce energy, are very hot and corrosive environments. Special steel is required to withstand the harsh operating environment, so titanium is alloyed (combined) with steel used in geothermal projects.

Titanium is used in electric vehicles and airplanes because of its strength and light weight.

Our bodies do not react negatively to it, so titanium has many medical applications in things like prosthetics, heart valves, pacemakers, joint replacements. tooth implants and hearing aids.

Titanium is also in many common products such as bicycles, golf clubs and high-tech equipment, and it is used as a pigment in paint and paper.

Despite titanium’s importance, and the Shubenacadie River’s tremendous potential for it, the Shubenacadie River deposit has never been mined.

The black heavy mineral sands of the Shubenacadie River.