Unearthing new energy potential

Materials World magazine
,
3 Apr 2011
Aerial view of the Saskatoba project

Michael Forrest asks Stan Szary, CEO, Saturn Minerals, about his company’s mining developments in Saskatchewan, western Canada, and their growing importance as a provider of energy now and in the future.

Western Canada is an energy-rich region. Alberta oil sands are second only to Saudi Arabia in oil reserves, and Northern Saskatchewan’s Athabasca Basin hosts the world’s largest, and highest grade, known uranium deposits. Saskatchewan has extensive lignite deposits with three open cast mines. These deposits have been known for over 100 years and today provide fuel for three power stations in the south of the province with an annual production of 12.5Mt. Saskatchewan is also Canada’s second largest conventional oil producer.

The underlying geological framework of hydrocarbon and uranium resources are Paleozoic and younger sedimentary rocks overlay the Precambrian basement in the southern part of the province. The older (Cambrian through Cretaceous) sedimentary rocks were formed from material deposited 500 to 65Ma in shallow seas that intermittently covered Western Canada. These marine rocks are host to the province’s vast resources of potash, oil and natural gas. In Saskatchewan, Tertiary rocks cover older sedimentary rocks in southern Saskatchewan and accumulated mainly in river and lake environments.

Coal (sensu lato) was found in Tertiary sediments that are an extension of similar horizons in the Dakotas, Montana and Wyoming and form the economic deposits of today. The three mines working the Ravenscrag formation supply thermal power stations that make up a substantial part of the province’s generating capacity. Reserves are extensive, greater than five billion tonnes. However, these coals are low sulphur lignites with equally low calorific values per tonne. Lignites are only useful in local power stations.

Exploration for higher grade coals has been carried out for over 100 years but has only recorded a few showings in limited areas. Some regional mapping, by L S Beck of the Saskatchewan Department of Mineral Resources in the 1970s, met with only local success where semi- and bituminous coal has been found in east-central Saskatchewan, near the border with Manitoba. The mapping was based on outcrops and stream cuts.

Two decades later, data from water wells, oil boreholes and other drillings found thicker coalbearing horizons, and were correlated by a study in 2003 by R Christopher, a research geologist, who identified the lower Cretaceous Mannville Group and the Jurassic-Cretaceous Success formation as hosts for coal-bearing strata. His work, however, had an emphasis of the regional correlation of these formations, while Beck’s work was mainly confined to the Pasquia Hills.

Down to the seam

Company activity in the past decade has revealed the true potential for coals within the Mannville Group, and has identified the style of deposition that had complicated the region’s coal geology. The Mannville Group and within it the Cantaur Formation were found to host coal seams of considerable thickness in the area of the Pasquia Hills.  

One of these companies is Saturn Minerals, which has been exploring the area for two years. Stan Szary, CEO of the firm, says drilling work has indicated good potential for coal mining. ‘Saturn, through a joint venture, had obtained licenses due east of the town of Hudson Bay along with other stakings around the Pasquia Hills,’ he explains. ‘Our first success came on 21 December 2009 when a rig on our Armit property near Hudson Bay intersected a 10.35m seam at a depth of approximately 112m. This was hole four of a programme of 12 drill holes comprising the 2009-10 winter drilling season in our Saskatoba project. The first three holes were drilled on the adjacent Elwood property.’

The drills were targeted by geological mapping and geophysical transient electromagnetic field anomalies. The upper 9.74m of the 10.35m intersection contained continuous coal with no mineral partings. A minor 1.26m thick coal seam was also intersected at a depth of 102.7m. The discovery hole was drilled vertically and coal intervals are estimated to be true thickness. Due to technical difficulties, the discovery hole did not reach target depth and was suspended at 136m in a layer of unconsolidated sand containing coal fragments. Szary cautions against placing undue reliance on the visual observations of the coal intercepts until the results of analytical work have been announced.

Variable formations

The Armit find was followed by 12 more holes totaling 1,680 vertical metres with six of them intersecting coal at least once with seams varying from 1.22-9.45m. Other holes did not intersect coal, and the Devonian basement limestone was met at a depth of 126m. This variability has been one of the challenges in this area and accounts for the long exploration gestation. Undoubtedly, the coals were developed in an unusual palaeoenvironmental setting that did not always correlate with the accepted geophysical delineation of potential coal-bearing strata. Core logging of the drilling indicates that the Cantaur Formation has two coal seams and that they resemble other coal-bearing formations, including a lower carbonaceous mud/clay palaeosoil horizon with distinct root imprints.

The Cantuar Formation hosts all of the significant coal horizons and has a variable thickness from 8.4-101m in the Hudson Bay township area. This variability can be accounted for by the formation infilling a topography of valleys and terraces, the morphology of which is controlled by major structural blocks. There is also infilling of karst solution depressions formed in the underlying Devonian limestones. This variability has resulted in separate micro basins with well-developed coal resources. Samples from the two coal horizons in the north central part of the Armit property reveal that, upon analysis, the lower seam, 9.4-9.7m thick, has a calorific value of 16,200 to 21,100kcal/kg as air-dried material.

Energy possibilities

The recognition of topographic controls in coal sedimentation has focused the ongoing exploration on geophysical techniques that will identify this sub-surface topography of Cretaceous age. ‘To this end, we hired Fugro Airborne Surveys in Ottawa to complete a 1,351km line survey over the Saskatoba project area, including Armit and our newly acquired licence areas to the east in adjacent Manitoba’, outlines Szary.

‘In combination with previous work, the combined data sets have served in refining and expanding Saturn’s proprietary model of coal-bearing basins in relation to a system of palaeovalleys and palaeokarstrelated depressions on the properties. Several preliminary drill targets have been identified on all gravity-surveyed blocks of the Saskatoba Project, and the company has filed an application for 19 diamond-coring drill holes in western Manitoba’.

Extensive bituminous coal recognition in an area not previously explored in detail has opened up the possibility for another energy-based industry in Sakatchewan. The province is a leader in carbon capture and storage and has recently signed an agreement with the Japan Coal Energy Centre, which has a track record in clean coal technology. SaskPower, the principal supplier of electricity in Saskatchewan, is leading the development of one of the world’s first and largest integrated carbon capture and storage demonstration projects at its Boundary Dam power station in Estevan.

‘These developments are set to increase Saskatchewan’s importance as an energy province in North America. The new coal deposits found by Saturn and companies such as Westcore Energy and Goldsource Mines in the Saschatchewan-Manitoba border area, will add to lignite and uranium [in] the energy mix,’ concludes Szary.

Further information

Stan Szary, CEO, Saturn Minerals Inc, 325-744 West Hastings Street, Vancouver, BC V6C 1A5. Tel: +1 (604) 685-6989. Website: www.saturnminerals.com