Fed by initial prospecting successes, the Wawa diamond hunt may have stirred some enthusiasm in its early days, but it now appears to be settling down to slower and more systematic exploration.
The area play was ignited by
Band-Ore’s surface sampling that year was positive, confirming results the prospectors had obtained on a 63-kg bulk sample that turned up 10 macrodiamonds. A campaign of short drill holes proved that Band-Ore was looking at heterolithic lamprophyre breccia, suggestive of the main diatreme facies of a kimberlite pipe.
At the opening of the year, samples from a large angular boulder 3 km northeast of the original showing proved to be diamondiferous. Further sampling of boulders and nearby lamprophyre outcrop returned both micro- and macrodiamonds. Stripping during the spring established that the bedrock source of the boulders was only about 5 metres away.
The new showing, first christened Area E, then renamed the Engagement Zone, has now yielded 141 macrodiamonds and over 9,000 microdiamonds from a total of 250 kg sent for analysis. The implied grade — a number that should still be treated with caution at this early stage — is a healthy 1.8 carats per tonne, and the largest diamond was a quarter-carat.
The lamprophyre bodies on the GQ property have no consistent orientation. Those nearest the original showing sampled by the prospectors strike generally northwest, but company maps do not show an obvious orientation of the host rocks of other showings on the property. That, however, may be an artifact of bedrock exposure, because showings are known only where logging roads have exposed the rocks.
A larger-scale bulk sample (12.5 tonnes) taken in the recent field season had 29 macrodiamonds, of various colors, and samples from outlying showings (100 metres to the northwest and 300 metres to the north of Area E) also proved to have macrodiamonds.
Results of a six- to eight-hole drilling program are pending.
So far, Festival has yielded a number of diamond showings where macrodiamonds have been recovered from weathered outcrop. At the heart of the discovery is an apparent diatreme, previously mapped as Archean-aged fragmental volcanic rocks.
The intrusive body lies about 3 km west along strike from Band-Ore’s Area E showing and outcrops over a 500-metre strike length.
In the early part of the field season Pele Mountain identified and sampled five new showings, all in mica-bearing heterolithic breccia. Small bulk samples (ranging from 15 to 32 kg in weight) from all five showings proved to have microdiamonds and three — Cristal, Krug and B-1 — returned macrodiamonds as well.
Samples from Krug and B-1 were taken from outcrop, but the Cristal samples (which yielded the best result, with 8 macrodiamonds) came from a boulder believed, from its size and angular shape, to be near its bedrock source.
Later on in the field season Pele Mountain located two more showings, Salon and Moet. Sampling at Moet, and further sampling at the Cristal showing, yielded more macrodiamonds.
One more showing, Dom Perignon, was found late in the summer on the west side of Perch Lake. Mapping of the breccia around the showing turned up a block of older basalt, about 3 metres long by 2 metres wide, in the breccia, further supporting Pele’s belief that the breccia was formed in a violent volcanic eruption.
The showing itself returned 12 macrodiamonds from ten small bulk samples whose total weight was 100 kg.
Another of the early Wawa diamond explorers,
Although the dykes were narrow, Tri Origin has correlated the intersections with geophysical anomalies that could represent wider kimberlite bodies at depth.
The true veterans in the Wawa hunt remain the joint venture of
Canabrava recently took over operation of the project from Kennecott and is investigating an outcrop of kimberlite found by tracing an 8-km boulder train back to its source. Kennecott had found two boulders in early 2001, and sampled both; these proved to be diamondiferous kimberlite and one of the boulders yielded two macrodiamonds.
Canabrava recently sent a 120-kg bulk sample from the outcrop for analysis, and is trying to map the kimberlite occurrence.
Boulders elsewhere on the property, whose locations match dispersion trains of kimberlite indicator minerals found in earlier geochemical surveys, are also being traced back to outcrop. The indicator minerals — chromite, chrome diopside, and G10 garnets — suggest the kimberlite boulders may have the right chemistry to be diamondiferous.
Canabrava is compiling the sampling results from the project and airborne geophysical surveys got under way in late August.
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