Diamond Fields International Ltd. announces results from Phase 3 Sampling Program
VANCOUVER, April 26 /CNW/ - Diamond Fields International (DFI-TSE) is
pleased to report results from Phase 3 of its Advanced Sampling Program on its
sea diamond concessions near Luderitz, Namibia. The program was designed to
conduct reconnaissance level sampling in the Boat Bay gravel and Gallovidia
Reef features as well as geological evaluation in defined portions of the
Marshall Fork and Elephant Basin features.
Phase 3 results provide further evidence that the Diamond Fields sea
diamond concessions have the potential to support a long-term, sea diamond
mining operation. De Beers Marine under contract, utilizing the mv Douglas
Bay, a vessel specifically built for prospecting and geotechnical work,
conducted the program between August and December of 1999. A total of 841
samples were collected from 35 anchor spreads. Diamonds were recovered in 130
of the samples.
Geological parameters recorded for the various prospects sampled will be
further input to the mining and sampling tool design processes currently
underway in the feasibility study.
Program Summary and Management Analysis
Randal Cullen, Diamond Fields' Principal Geologist, directed the program
and is the qualified person responsible for the technical results in this news
release. As part of the contract, De Beers Marine provided detail sample logs
collected by qualified technicians while Diamond Fields provided the
geologists for geological mapping and interpretation.
<<
Phase 3 Summary Results
Ave.
Spreads Total Samples Total Stone
Feature Spreads Mineralized Ratio Samples Mineralized Ratio Carats Size
------- ------- ----------- ----- ------- ----------- ----- ------ -----
Gallovidia
Reef 15 9 60% 409 19 5% 4.8 0.24
Boat Bay 15 15 100% 322 70 22% 20.0 0.16
Elephant
Basin 3 3 100% 76 30 39% 29.8 0.32
Marshall
Fork 2 2 100% 34 11 32% 4.7 0.26
Total 35 29 83% 841 130 16% 61.3 0.23
>>
The Douglas Bay has tandem ``Mega drills'' mounted 40 meters apart on the
starboard side. The Mega drill is a percussion type drill with a 0.71 square
meter cross section area. The drill is advanced by a hammering action and
cuttings are recovered by airlift. The standard limit of penetration is 6
meters although removal of the stabilizing skirt allows deeper holes to be
attempted. Samples were collected in clusters of three representing 2.1 square
meters of excavation per sample site. Sampling operations were undertaken on
300 meter by 400 meter anchor ``spreads''. The number of samples collected
within each spread averaged 24 and ranged from a low of 9 to a high of 40.
Spacing between sample sites was a minimum of 40 meters. Samples were
processed on board and x-ray concentrates were canned for sorting on land in
accordance with De Beers Marines' strict security regimen. All samples were
sorted in the presence of Diamond Fields' supervisory personnel at the De
Beers Marine sorting facility in Windhoek.
Marshall Fork Phase 3 Advanced Sampling
The first objective of sampling in the Marshall Fork feature was to
assess the diamond recovery efficiency of the Mega drill in sediment similar
to that anticipated in the Gallovidia Reef feature. By resampling a portion of
Marshall Fork already sampled with the Wirth drill during Phase 2, provisional
comparisons were made between the Mega drill and Wirth drill recoveries. In
general, the results show the recoveries from the Wirth drill were higher than
that of the Mega drill in the geological terrain sampled. The differences in
recoveries were more pronounced in the thin sediment areas sampled.
The small footprint and operational limitations of the Mega drill in this
terrain suggests that the results can only be used as a qualitative
measurement of diamond potential. Mega drill sampling indicates only the
presence of and extent of mineralization and gives an indication of diamond
sizes. In order to evaluate grade, a more quantitative method of bulk sampling
will be required.
The second objective was to explore for basal gravel horizons in areas
where the Wirth drill did not penetrate resistive `false footwall' during
Phase 2 sampling. The Mega drill was able to penetrate to footwall rock in 50%
of the samples attempted and indicated the presence of previously unsampled
basal gravels. This positive result further suggests the current indicated
resource estimate for Marshall Fork, calculated on Wirth drill results, may
underestimate the true potential of the deposit.
In the feasibility study, mining tool design will incorporate the ability
to excavate these resistive layers to enable recovery of the basal gravel
horizon and accompanying diamonds.
Elephant Basin Phase 3 Advanced Sampling
Three spreads encompassing 76 samples were collected over 320,000 square
meters of previously defined resource areas to provide comparative results
between the Bauer tool and the Mega drill. Diamond recoveries, diamond sizes
and extents of mineralization indicated by the Mega drill were comparable to
those for the earlier (1995) Bauer tool program. The Phase 3 sampling
indicates 39% of samples contained diamonds, a result that coincides with
previous sampling and provides support for the belief that the Elephant Basin
and adjacent Reef Edge features host a considerable diamond resource. Discreet
areas of these features are targeted for resource definition sampling after
mining operations have commenced in Marshall Fork.
In the feasibility study, in conjunction with mining tool development, an
improved sampling tool is also being developed to provide more accurate
diamond recovery data suitable for resource and reserve definition.
Gallovidia Reef Phase 3 Reconnaissance Sampling
Reconnaissance sampling in the Gallovidia Reef feature tested several
southwest-facing embayments and recessive gullies throughout the feature. A
total of 409 samples were collected from 15 spreads. Diamonds were recovered
in 19 sample sites for a mineralized ratio of 5%. The low success ratio was
disappointing, but given the limitations of the sampling tool in thin sediment
areas, not conclusive. Further exploration work in the Gallovidia Reef feature
is contingent upon updated geophysical surveys and development of the
previously mentioned sampling tool. Based on Phase 3 results further
exploration work has been prioritized behind plans for work on other known
features in the south of the license area.
Boat Bay Gravel Phase 3 Reconnaissance Sampling
Reconnaissance sampling in the 60 square kilometers Boat Bay Gravel
feature consisted of 322 samples collected from 15 anchor spreads. Seventy
(70) sample sites were mineralized representing a 22% success rate. This
sampling identified the presence of diamonds in perched gravel horizons over a
large area. Up to three separate gravel layers were identified in the top 10
meters of sediment with gravel thickness ranging from 0.4 to 1.5 meters. Of
the 15 spread areas sampled, 13 were located along the 30 meters contour, a
water depth amenable to large scale, low unit cost dredging techniques.
The size and extent of the perched gravel layers representing ancient
beach level horizons are unparalleled in the known sea diamond areas along the
southwestern coast of Africa. The existence of these diamondiferous gravels
supports the premise that Luderitz Bay (including Reef Edge, Boat Bay, Conical
Beach and Staple Basin features) represents the largest diamond trap site on
the Namibian coast, able to capture wind and water transported diamonds.
Previous sampling of deposits on the western edge of the Boat Bay feature
has demonstrated that a high-grade basal gravel horizon is present. Diamond
Fields geologists believe that the basal gravel horizon could extend under the
entire Boat Bay feature area.
The economics of mining a basal gravel horizon below thick cover will be
enhanced by the presence of low-grade diamondiferous perched gravel layers in
the upper sediments. Further exploration will target the basal gravel horizon
with geophysics to determine sediment thickness and sampling methods capable
of penetrating thick sediments and indicating diamond grades.
Conclusions
The Phase 3 program successfully increased the understanding of diamond
deposition in the EPL1607 concession which includes the above mentioned areas.
Diamond Fields remains of the belief that the concession has an excellent
potential to support a highly profitable, sea diamond mining operation for
many years in the future. Based on the future availability of a custom built
sampling tool, Diamond Fields geologists have prioritized further exploration
activities to include reconnaissance sampling in the Gallovidia Reef feature
and bulk sampling to determine the grade of diamondiferous perched gravels
discovered in the Boat Bay feature and the extent and grade of basal gravels
there.
Feasibility Study Impacts
The current feasibility study for an initial mining operation will
include the planned development of a sampling tool compatible with EPL1607
seabed geology and with the proposed mining system. Based on the experience
gained during Phase 3, the operating criteria and sampling requirements for
Gallovidia Reef and Boat Bay have been identified. Sufficient resources have
been identified to support the feasibility study for an initial mining
operation. The feasibility study will also prioritize and plan a resource
definition sampling program to generate additional reserves.
Acknowledgement
The world's leading sea diamond exploration and mining company, De Beers
Marine, under their strict security regimen, conducted all sampling
activities. The Phase 3 work was completed on time and within budget at a
total cost of approximately US$2.2 million. All activities were carried out
safely with no reported accidents and conformed to Diamond Fields'
environmental contract with the Namibian authorities. De Beers Marine is an
ISO 14001 certified company and under separate contract to Diamond Fields
collected additional environmental baseline data to support potential future
mining operations. Diamond Fields would like to take the opportunity to
publicly commend De Beers Marine management and sea-going personnel associated
with the overall Diamond Fields program for a job well executed in a safe and
environmentally sound fashion.
Diamond Fields is an international diamond exploration and mining company
and continues to pursue diamond business opportunities worldwide and is
currently conducting a feasibility study for the development of its sea
diamond concessions in Namibia.
ON BEHALF OF THE BOARD OF DIRECTORS
OF DIAMOND FIELDS INTERNATIONAL LTD.
Daniel D. Johnson
President and Director
-30-
For further information: (604) 682-2113; Investor Relations: Don
Halliday (604) 608-0826; Website - www.diamondfields.com
DIAMOND FIELDS INTERNATIONAL LTD. has 26 releases in this database.
PHIL
|
