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Post by Franko10 ™ on Jan 31, 2005 13:43:07 GMT -5
Kensington Resources Ltd.: Fort A La Corne 2001 Grade And Value Estimates
VICTORIA, British Columbia--(BUSINESS WIRE)--Jan. 16, 2003
Kensington Resources Ltd. (TSX VENTURE:KRT) (the "Company") today reports the interpretative grade estimates and modeled value results for the 2001 large diameter drilling program at Fort a la Corne located in east-central Saskatchewan. De Beers Canada Exploration Inc., the operator of the project, oversaw preparation of an evaluation report authored by managers and geoscientists in Mineral Resource Services (MRS) a department of De Beers located in Johannesburg, South Africa. The report, for which preliminary results were supplied during July 2002, was finalized in November 2002 from currently available information and modeled by De Beers using proprietary techniques. Macrodiamond recoveries for 2000 and 2001 were carried out at De Beers' facilities located in Canada and South Africa. The total microdiamond inventory that was recovered in early 2002 and utilized in the current grade forecasts was recovered both from Lakefield Laboratory in Canada and De Beers' laboratories in Kimberley, South Africa. In addition, results of the 2001 macrodiamond breakage study by De Beers are reported in this news release. Services and interpretations rendered to the Joint Venture by De Beers are not independent or "at arms-length" due to their involvement in the project as a partner. Valuation of the same parcels of 2000 and 2001 macrodiamonds utilized by De Beers was made by WWW International Diamond Consultants Ltd. ("WWW").
141 Diamond Recovery and Grade Estimates
A total of 769 tonnes of kimberlite was excavated in 2001 from kimberlite 141 utilizing large diameter drillholes. From this, 431 macrodiamonds (greater than 1.5 mm in size) weighing 42.455 carats were recovered and added to the existing kimberlite 141 inventory of 248 stones weighing 21.22 carats recovered from program samples acquired in 2000. Fewer carats than initially anticipated were recovered from the 2001 program resulting in lower minibulk sample grades and less stones in the greater than 0.5 carat range (particularly, in comparison to 2000 samples). Some reasons for this discrepancy include:
i) 3 of 10 large diameter drillholes did not sample all of the way to base of kimberlite and intervals of macrodiamond-bearing kimberlite with known or estimated large stone potential were not sampled,
ii) the lower treatment cutoff and crush size utilized in 2000 were changed in 2001 resulting in greater diamond lock-up, coupled with non-recovery of diamonds in the 1.5 mm to 1.0 mm range, and
iii) discovery of geological complexity between and within kimberlite phases that may be accompanied by variations in diamond distribution.
Table 1 shows sample grades for the eleven 610 mm diameter boreholes drilled in 2000 and 2001 that range up to 41.5 carats per 100 tonnes (cpht) and cumulatively average 5.5 cpht. Notably, the high-end sample grade includes the 3.335 carat stone recovered from a 2001 sample. Individual minibulk sample grades are not considered representative of the average grade of the kimberlite, rather the range of values likely brackets the actual grade of specific kimberlite phases or units, of which there may be several within a given drillhole. Grade estimates derived from statistical modeling of diamond size distributions for kimberlite 141 ranged from 5 to 12 cpht. These estimates are extrapolations for stones greater than 1.5 mm in size and pertain only to the central portion of kimberlite 141 where testing was conducted during 2000 and 2001.
Table 1: Minibulk Sample Grades for 2000 and 2001 Drillholes in
Kimberlite 141
---------------------------------------------------------------------
Drillhole Year Range of Minibulk Average Borehole Preliminary
Drilled Sample Grade(cpht) Sample Grade(cpht) Estimate of
Number of
Kimberlite
Phases
---------------------------------------------------------------------
141-20 2001 0 - 41.5 6.6 3
141-21 2001 0 - 16.1 6.4 4
141-22 2001 0 - 17.7 7.2 2
141-23 2001 0 - 11.4 5.5 2
141-24 2001 0 - 21.3 5.2 3
141-25 2001 0 - 9.7 2.7 2
141-26 2001 0 - 17.2 5.5 at least 2
141-27 2001 0 - 6.9 2.1 2
141-28 2001 0 - 13.9 4.2 3
141-04 2000 0 - 34.3 8.4 4
141-05 2000 0 - 19.7 7.1 4
---------------------------------------------------------------------
141 Modeled Diamond Values and Preliminary Assessment of Revenue
Actual average parcel diamond values for the 2001 stones were posted at $US 52.60/carat, reflecting a substantial increase from $US 33.67/carat for the 2000 stones. De Beers notes that since the valuation of the 2000 diamond parcel, the rough market has undergone a negative shift, a trend that only recently is showing signs of a reversal. For the purpose of modeling diamond value, the 2000 and 2001 parcels were not valued as a single parcel; rather they were combined on paper only, keeping the diamonds separate for later layout exercises that are used to determine if the recovered diamonds differ in a gross sense across the 140/141 kimberlite body as drilled to date.
Modeled dollar per carat values in diamond exploration takes account of the expected diamond size distribution from any potential, future production scenario. An average dollar/carat value is based on diamond values extrapolated upwards to include recoveries modeled in the larger diamond sieve sizes. A model for 141 was fitted around the actual dollar per carat per sieve class recoveries leading to average values for all of the applicable diamond sieve categories. Combination of the modeled revenue curve and diamond size distribution yielded updated dollar per carat value estimates. This gave modeled values for macrodiamonds from 141 that range from $US 20 to 220/carat. In light of the difference between modeled parcel and actual values, De Beers suggests that for small diamond samples, the actual parcel value is highly variable and the actual dollar per carat value for a potential producer is usually understated.
Modeled values were combined with grade estimates and dollar per tonne values were calculated for the modeled size distributions. Hence, as a preliminary assessment of revenue based on value and grade estimates, De Beers indicates a range from $US 1 to 26/tonne. Confidence limits of 80% for the modeled values and preliminary assessment of revenue reflect variability in diamond size distribution and diamond value, and not of grade. However, the Company considers all estimates, particularly those of grade, with low confidence in respect of newly-defined geological complexity (at least 4 phases of kimberlite) and variations in diamond size distribution in the 141 and 140 bodies, overall small diamond parcel sizes, and low levels of sampling across the breadth of the body (nugget-effect).
Valuation of the 2000/2001 diamonds was conducted during November 2002 by WWW International Diamond Consultants Ltd. (hereafter, WWW). WWW indicated an overall average value based on its open market price book some 15-20% higher than that listed by De Beers for the same diamond parcels. The De Beers valuations were made utilizing the DTC June 2002 price book. The single large stone measuring 3.335 carats that was recovered from large diameter drillhole 141-20 was given a value of $US 450/carat, compared to $US 390/carat attributed by De Beers. WWW also pointed out the technical difficulties of putting a realistic market value on a relatively small geological sample. The principals of WWW are associated with the Kensington Technical Committee and also may have a financial interest in Kensington Resources.
Macrodiamond Breakage in 2001 Samples
VICTORIA, British Columbia--(BUSINESS WIRE)--Jan. 16, 2003
Kensington Resources Ltd. (TSX VENTURE:KRT) (the "Company") today reports the interpretative grade estimates and modeled value results for the 2001 large diameter drilling program at Fort a la Corne located in east-central Saskatchewan. De Beers Canada Exploration Inc., the operator of the project, oversaw preparation of an evaluation report authored by managers and geoscientists in Mineral Resource Services (MRS) a department of De Beers located in Johannesburg, South Africa. The report, for which preliminary results were supplied during July 2002, was finalized in November 2002 from currently available information and modeled by De Beers using proprietary techniques. Macrodiamond recoveries for 2000 and 2001 were carried out at De Beers' facilities located in Canada and South Africa. The total microdiamond inventory that was recovered in early 2002 and utilized in the current grade forecasts was recovered both from Lakefield Laboratory in Canada and De Beers' laboratories in Kimberley, South Africa. In addition, results of the 2001 macrodiamond breakage study by De Beers are reported in this news release. Services and interpretations rendered to the Joint Venture by De Beers are not independent or "at arms-length" due to their involvement in the project as a partner. Valuation of the same parcels of 2000 and 2001 macrodiamonds utilized by De Beers was made by WWW International Diamond Consultants Ltd. ("WWW").
141 Diamond Recovery and Grade Estimates
A total of 769 tonnes of kimberlite was excavated in 2001 from kimberlite 141 utilizing large diameter drillholes. From this, 431 macrodiamonds (greater than 1.5 mm in size) weighing 42.455 carats were recovered and added to the existing kimberlite 141 inventory of 248 stones weighing 21.22 carats recovered from program samples acquired in 2000. Fewer carats than initially anticipated were recovered from the 2001 program resulting in lower minibulk sample grades and less stones in the greater than 0.5 carat range (particularly, in comparison to 2000 samples). Some reasons for this discrepancy include:
i) 3 of 10 large diameter drillholes did not sample all of the way to base of kimberlite and intervals of macrodiamond-bearing kimberlite with known or estimated large stone potential were not sampled,
ii) the lower treatment cutoff and crush size utilized in 2000 were changed in 2001 resulting in greater diamond lock-up, coupled with non-recovery of diamonds in the 1.5 mm to 1.0 mm range, and
iii) discovery of geological complexity between and within kimberlite phases that may be accompanied by variations in diamond distribution.
Table 1 shows sample grades for the eleven 610 mm diameter boreholes drilled in 2000 and 2001 that range up to 41.5 carats per 100 tonnes (cpht) and cumulatively average 5.5 cpht. Notably, the high-end sample grade includes the 3.335 carat stone recovered from a 2001 sample. Individual minibulk sample grades are not considered representative of the average grade of the kimberlite, rather the range of values likely brackets the actual grade of specific kimberlite phases or units, of which there may be several within a given drillhole. Grade estimates derived from statistical modeling of diamond size distributions for kimberlite 141 ranged from 5 to 12 cpht. These estimates are extrapolations for stones greater than 1.5 mm in size and pertain only to the central portion of kimberlite 141 where testing was conducted during 2000 and 2001.
Table 1: Minibulk Sample Grades for 2000 and 2001 Drillholes in
Kimberlite 141
---------------------------------------------------------------------
Drillhole Year Range of Minibulk Average Borehole Preliminary
Drilled Sample Grade(cpht) Sample Grade(cpht) Estimate of
Number of
Kimberlite
Phases
---------------------------------------------------------------------
141-20 2001 0 - 41.5 6.6 3
141-21 2001 0 - 16.1 6.4 4
141-22 2001 0 - 17.7 7.2 2
141-23 2001 0 - 11.4 5.5 2
141-24 2001 0 - 21.3 5.2 3
141-25 2001 0 - 9.7 2.7 2
141-26 2001 0 - 17.2 5.5 at least 2
141-27 2001 0 - 6.9 2.1 2
141-28 2001 0 - 13.9 4.2 3
141-04 2000 0 - 34.3 8.4 4
141-05 2000 0 - 19.7 7.1 4
---------------------------------------------------------------------
141 Modeled Diamond Values and Preliminary Assessment of Revenue
Actual average parcel diamond values for the 2001 stones were posted at $US 52.60/carat, reflecting a substantial increase from $US 33.67/carat for the 2000 stones. De Beers notes that since the valuation of the 2000 diamond parcel, the rough market has undergone a negative shift, a trend that only recently is showing signs of a reversal. For the purpose of modeling diamond value, the 2000 and 2001 parcels were not valued as a single parcel; rather they were combined on paper only, keeping the diamonds separate for later layout exercises that are used to determine if the recovered diamonds differ in a gross sense across the 140/141 kimberlite body as drilled to date.
Modeled dollar per carat values in diamond exploration takes account of the expected diamond size distribution from any potential, future production scenario. An average dollar/carat value is based on diamond values extrapolated upwards to include recoveries modeled in the larger diamond sieve sizes. A model for 141 was fitted around the actual dollar per carat per sieve class recoveries leading to average values for all of the applicable diamond sieve categories. Combination of the modeled revenue curve and diamond size distribution yielded updated dollar per carat value estimates. This gave modeled values for macrodiamonds from 141 that range from $US 20 to 220/carat. In light of the difference between modeled parcel and actual values, De Beers suggests that for small diamond samples, the actual parcel value is highly variable and the actual dollar per carat value for a potential producer is usually understated.
Modeled values were combined with grade estimates and dollar per tonne values were calculated for the modeled size distributions. Hence, as a preliminary assessment of revenue based on value and grade estimates, De Beers indicates a range from $US 1 to 26/tonne. Confidence limits of 80% for the modeled values and preliminary assessment of revenue reflect variability in diamond size distribution and diamond value, and not of grade. However, the Company considers all estimates, particularly those of grade, with low confidence in respect of newly-defined geological complexity (at least 4 phases of kimberlite) and variations in diamond size distribution in the 141 and 140 bodies, overall small diamond parcel sizes, and low levels of sampling across the breadth of the body (nugget-effect).
Valuation of the 2000/2001 diamonds was conducted during November 2002 by WWW International Diamond Consultants Ltd. (hereafter, WWW). WWW indicated an overall average value based on its open market price book some 15-20% higher than that listed by De Beers for the same diamond parcels. The De Beers valuations were made utilizing the DTC June 2002 price book. The single large stone measuring 3.335 carats that was recovered from large diameter drillhole 141-20 was given a value of $US 450/carat, compared to $US 390/carat attributed by De Beers. WWW also pointed out the technical difficulties of putting a realistic market value on a relatively small geological sample. The principals of WWW are associated with the Kensington Technical Committee and also may have a financial interest in Kensington Resources.
Macrodiamond Breakage in 2001 Samples
