Fred Breaks is at it again. The Ontario Geological Survey geologist who discovered
Breaks published news of his latest find in January in the OGS Miscellaneous Paper No. 169. The paper, co-authored with two colleagues from the U.K.’s Open University, is in part a more detailed look at reconnaissance work carried out in the early 1990s by OGS geologist Denver Stone near Pakeagama Lake in the North Spirit Lake region, some 170 km north of Red Lake, Ont.
In that earlier work, Stone identified a series of highly aluminous granites at a contact between the Sachigo and Berens River geological sub-provinces. Also, from the Pakeagama Lake pegmatite he collected samples that proved to contain anomalous values of tantalum, cesium and lithium.
Breaks returned to the area in 1998 to conduct mapping and sampling, and identified an extremely fractionated, strongly zoned, petalite-bearing pegmatite that now ranks as the second-largest pegmatite system of its kind in Ontario, after the Big Whopper deposit.
Breaks states in his report that the Pakeagama pegmatite has the potential to host economic quantities of high-value rare metals, namely tantalum, cesium, rubidium and lithium.
He considers the Pakeagama pegmatite to be highly prospective for rare metals for several reasons:
- a related pluton contains muscovite, indicating potential for evolved pegmatite mineralization;
- there is an occurrence of tourmaline, which contains boron — an element important in the transport of rare metals; and
- there are ferro-tantalite rims (identified by electron microprobe analysis) surrounding ferro-columbite mineral cores — an indicator of significant fractionation.
Already, seven economically important, tantalum-rich minerals have been confirmed in the Pakeagama pegmatite, including the exotic minerals mangano-tantalite, ferro-tantalite, mangano-columbite, microlite, ferro-tapiolite, wodginite and stibio-tantalite (one of only 11 occurrences of this mineral globally).
Pakeagama’s well-defined evolutionary trend in composition from mangano-columbite to mangano-tantalite indicates a potential for tantalum-rich zones in the pegmatite, as is seen at the Tanco rare metals mine at Bernic Lake, across the border in Manitoba.
Sudbury-based
In order to earn its interest, Houston Lake must issue 200,000 shares, make cash payments totalling $150,000 and spend $63,000 on exploration over three years. The property is also subject to a 2.5% net smelter return royalty.
Geologically, the Pakeagama pegmatite dips steeply, has a southeast-northwesterly trend and is exposed at surface over a strike length of 250 metres and a width of 10-70 metres. The structure remains open in all directions.
A narrow tantalum-bearing aplite dyke occurs 400 metres to the southeast, indicating that the rare-metal pegmatite system may continue beyond the larger exposed area.
As well, a pronounced lithium-cesium anomaly extends for more than 100 metres from the Pakeagama pegmatite, suggesting the presence of a second rare-metal pegmatite body.
Apart from the tantalum mineralization, the Pakeagama pegmatite system contains pollucite crystals up to 4 cm in length, representing only the fourth occurrence of pollucite recorded in Ontario. Pollucite is the only ore mineral for cesium, and its presence indicates a potential for cesium-rich zones.
The pegmatite’s average rubidium value of 1.11% is the highest bulk content for rubidium yet found in northwestern Ontario, and lithium oxide values ranging from 3.8% to 4.7% have been returned from the channel sampling of a spodumene-quartz core within the pegmatite.
Houston Lake plans to begin a program of mapping, stripping, trenching and sampling at Pakeagama in preparation for drilling. Also this summer, an OGS crew will be returning to the area to carry out another phase of work.
Houston Lake’s president, Grayme Anthony, stresses that what differentiates the Pakeagama project from Avalon’s Big Whopper project is the former’s higher potential for the discovery of tantalum- and cesium-rich zones. At the Big Whopper, tantalum and cesium mineralization is more diffuse and will likely be recovered only as a byproduct of petalite production.
Most notable at Pakeagama is a strong trend of increasing tantalum content in the manganese-rich portion of the columbite-tantalite quadrilateral plot — a trend that is characteristic of deposits enriched in tantalum, such as the Tanco pegmatite.
In a related development, shortly after becoming involved in Pakeagama, Houston Lake signed a option agreement to acquire a second rare-metals play in the region. This 1,024-ha property is near Favourable Lake, 175 km north of Red Lake and 50 km from Pakeagama. The new property covers a portion of the Severn River pluton, a highly aluminous granite similar to that noted at Pakeagama Lake.
Under the agreement, Houston Lake will earn a 100% interest in the Favourable Lake property from a prospector by issuing 200,000 shares, and spending $76,800 over three years. The property is also subject to a 2.5% net smelter return royalty.
The rare metals tantalum, cesium, rubidium and lithium have unique properties that are sought after for use in various high-tech applications. Tantalum is used in electrical capacitors, tantalum-carbide tools, chemical alloys and medical devices. Cesium is used in calibrated drill muds, power generators, motors, opto-electronics and as a chemical catalyst in DNA separation. Rubidium and lithium are used primarily by the ceramics and glassware industries.
World tantalum supply is largely dependent on just three producers in Australia, Zimbabwe and Canada, and the Tanco mine in Manitoba is currently processing only tailings. Demand for tantalum has had a 10% annual growth rate since 1992, fueled mainly by the computer and mobile-communications industries. The mid-market spot price for tantalum was recently US$32 per lb. Ta2O5.
While Pakeagama has become Houston’s primary focus, the company is still active at its Tib Lake palladium-platinum-gold property, north of Thunder Bay, Ont., some 15 km from the Lac des Iles palladium mine.
Houston Lake has already fulfilled its first-year option conditions at Tib Lake by spending $110,000 on exploration, issuing 25,000 shares and paying $7,500 in cash. The company has also made the final cash payment of $15,000, which allows it to begin the second-year option period. It is still required to spend another $200,000 and issue 50,000 shares by March 2000 in order to earn a full interest in the property.
Houston Lake’s work at Tib Lake has consisted of line-cutting, magnetic and electromagnetic geophysical surveys, and the drilling of a single 150-metre hole, No. 14. This new hole was collared 5 metres from hole 9, which returned 13.6 metres of 1.68 grams PGE (platinum group elements, here defined as palladium-platinum-gold) per tonne in a program carried out by a third party in the mid-1990s. While Houston Lake’s twinned hole intersected similar geology, the coincident mineralized intersection returned only 0.31 gram PGE over a true width of 10.6 metres.
A subsequent check assay by Chemex Labs of hole 9 returned a grade of 1.6 grams PGE per tonne over 13.1 metres of true width.
Houston Lake intends to return to the property this summer to continue mapping and sampling, with particular attention being paid to two targets, named the Kuhner and Road occurrences.
In the past few months, Houston Lake raised gross proceeds of $236,000 from
a $300,000 offering. The company issued units priced at 40 cents apiece, with each unit consisting of one flow-through share, one ordinary share and half of a share-purchase warrant. The holder of a full warrant may buy a non-flow-through share for 30 cents over one year.
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