Hi paul,
Hypasbyssal also means deep seated. In the snap Lake model, rather than a kimberlite pipe forming and erupting to surface, a cone sheet developed. Also, at Snap Lake, the kimberlite magma is of the type II variety (low in volitiles-this is the first publicly ackowledged occurance of type II kimberlite outside of South Africa). The diameter of the cone sheet is about 5 kilometers. The thickness averages about 2.6 meters. The density of the kimberlite is about 3 gms/cm3. The dip of the cone is about 15 degrees to the apex. There is some speculation that at the apex will be found a blind feeder/pipe to the cone sheet. Other interesting tidbits are that the mineral chemistry suggests depths of origin of 300 kilometers (similar to Mir in Russia) versus 200 kilometers at Ekati. Because emplacement was not phreatomagmatic, there will be less breakage of diamond, less resorption and less dilution by addition of country rock. Also, as in type II kimberlite in South Africa, grades will likely be highly uniform. If you are new to this thread, I suggest you spend some time at Winspears web site and looking at past post here.
regards,
teevee |
