UBC diamond research records a first for science

Thanks to an opportunity to study rocks “that most petrologists
would die for,” UBC researchers are set to make diamond exploration
history with the publication of results of their analysis of so-called
diamondiferous rocks from Canada’s Northwest Territories.

While their findings, which support claims that a region called
the Slave craton may hold the biggest diamond find of the century,
may not represent a first in the diamond mining industry, the fact
that they are publishing them does.

“Our discoveries and results on the Slave mantle are new to science.
The irony is, however, that many industry labs have similar scientific
results which will never be published,” says Assoc. Prof. Kelly
Russell, head of UBC’s Igneous Petrology Lab.

By analysing rock samples forced to the surface of the 2.6-billion-year-old
Slave craton in explosive torrents of molten rock called kimberlite,
petrologist Maya Kopylova and Russell have constructed detailed
geotherms–geological profiles of the earth’s temperature with increasing
depth and pressure. They are also gaining insight into the composition
of the earth’s mantle in the region beneath the Slave craton.

The samples are taken from kimberlite pipes, formed as kimberlite
magma travels rapidly upward from depths as great as 400 km before
exploding through the earth’s surface carrying fragments of mantle
rock and, in the right conditions, possibly diamonds to the surface.

The geotherms show that at least some of the kimberlite pipes in
the region, which originated between 52 million and 400 million
years ago, passed through depths and conditions in which diamond
deposits are formed.

The kimberlite samples Kopylova and Russell have examined came
from a kimberlite pipe held by Canamara Geological, a Canadian company
that is one of several smaller companies who, along with the large
Australian mining company BHP and Monopros, a subsidiary of South
Africa’s DeBeers, have acquired land in the region.

Using an electron microprobe and thermodynamic equations, Kopylova
has succeeded in mapping a “diamond window,” where mantle pressures
and temperatures are right for diamond formation. She can now determine
whether or not a particular kimberlite pipe is likely to have passed
through the diamond window and perhaps to have sampled diamondiferous
rock.

-30-