Margaret Lake Diamonds announces Arctic Star Sequoia Kimberlite Complex’s Indicator Mineral Chemistry Points to Large Diamonds, Diagras Project, NWT
Margaret Lake Diamonds announces Arctic Star Sequoia Kimberlite Complex’s Indicator
Mineral Chemistry Points to Large Diamonds, Diagras Project, NWT
VANCOUVER, B .C. / September 9 th 2021 / Margaret Lake Diamonds Inc. ("MLD" or the
"Company") (TSXV: DIA) (FKT:M85) (OTC PINK:DDIAF) is pleased to announce that
Arctic Star has received diamond indictor mineral results and an interpretation of these from
Chuck Fipke for the first hole into the Sequoia Kimberlite complex. The results demonstrate the
existence of a number of indicator types that occur with diamonds and strongly suggest the
presence of diamonds. Furthermore, indicator minerals of identical multi-element chemistry to
those found as inclusions in large >50-carat diamonds worldwide are abundant. The indicators
from different kimberlite types are starkly different. These observations are in agreement with
the caustic diamond results, which show the different kimberlite types have different stone/kg
counts and also hints at a coarse diamond distribution. Ultimately a bulk sample will be required
to confirm the diamond distribution and this is the normal path of progress for diamond
exploration. Prior to this, a drill program defining the volumes of the different kimberlite types
and their caustic fusion diamond distribution is planned for spring 2022.
Samples of kimberlite core were sent to C.F. Mineral Research Ltd. in Kelowna, B.C. for
indicator mineral analysis. C.F. Minerals is a global-leading kimberlite and diamond analytical
research facility lead by Chuck Fipke - one of the founders of the Ekati diamond mine. At the lab,
the samples were lightly crushed with heavy minerals separated by dense media gravity methods.
Oxides and silicates are split using magnetic separation. Candidate diamond indicator minerals
are selected by a minerologist, mounted and scanned for chemical composition using a scanning
electron microscope (SEM). Mineral grains that “light up” under different element scans are
mapped and then assayed by electron microprobe. The microprobe results are presented here.
Mineral grains that grow concurrently while touching or within diamonds have distinct chemistry
and are diagnostic of the presence diamonds and also of the rock type that host the diamonds at
great depths. Readers should note the following deep mantle, high-pressure rock types associated
with diamond mineralization that are noted in this release.
Lherzolite: Garnet, Clinopyroxene and Olivine (Certain types host >50carat diamonds).
Harzburgite: Garnet (low calcium, high chrome), Orthopyroxene and Olivine (Source of the
desirable “G10” garnets and ‘P’ type diamonds). Chromite: Harzburgite: A garnet poor,
Chromite rich variety of above. Eclogite: Garnet and Pyroxene (Source of ‘E’ Type diamonds).
The samples analyzed thus far are from the Sequoia kimberlite, hole DG-2021-04 located in the
geographical center of the complex. One sample from the interval 51m to 89m (5.1kg) from the
Coherent Kimberlite (“CK”), another sample from the interval 105m to 136m (5.1kg) logged as
Volcanoclastic Kimberlite transitional (“VKt”) into Coherent Kimberlite and a sample from the
interval 136m to 150m (5.3kg) logged as Volcanoclastic Kimberlite (“VK”).
Chuck Fipke reports: “The two Volcanoclastic samples are dominated by diamond inclusion
minerals (high calcium G10 garnets (classifying as G10-2 and G10-3) found in Lherzolite, (G11)
garnets and diamond inclusions (CP5) clinopyroxenes that have been found as inclusions in big
diamonds ranging from 52 to 102 carat from the Ekati diamond mine (coined "Di$") as well as
chromite rich harzburgite containing diamond inclusion chromites and orthopyroxenes. Current
research suggests these larger diamonds come from great depths >400km.
The diamond inclusion minerals from lherzolite (DI$, CP5 G9/G11 indicators mentioned above)
found in Sequoia is identical to those present in Letseng (In Lesotho), Victor (In Canada), and
Lucara’s Karowe Mine (Botswana). These kimberlites are typically lower grade but contain very
large high-quality diamonds routinely recovered during run-of-mine operations. This is based on
analysis of inclusions from over 335 diamonds from these sources as well as Ekati’s large
stones. The classification scheme relies on the multi-element analysis of the Sequoia indicator
minerals having the same chemical composition as the indicators from known large diamond
sources.
As well as passing through and sampling of lherzolite, the Sequoia kimberlite has sampled
diamond bearing chromite harzburgite as evidence by the abundant 99 diamond inclusion
composition chromites and 45 diamond inclusion orthopyroxenes present. These additional
mineralogies could account for any smaller diamonds recovered. The two Volcanoclastic
samples have relatively few eclogitic type garnets, which can also be associated with diamond
mineralization.
In contrast to the VK samples, the CK sample from 51 to 89 meters has abundant Group1
eclogitic garnets where the SEM shows 51 diamond inclusion eclogite grains. This sample also
has the large diamond inclusion llerzolite minerals and the subordinate diamond bearing (low
calcium-high chrome G10-7 and G10-9) pyrope garnet bearing harzburgite not present in the
VK as well as chromite harzburgite present in the VK. A total of 80 diamond inclusion
composition chromites and 10 diamond inclusion olivines were recovered from the chromite
harzburgite.
It is also worthy to note that the overall abundance of the lherzolite (DI$, CP5 G9/G11
indicators) large diamond inclusion minerals recovered from the three Sequoia DG 2021-04 drill
hole samples exceeds, per sample weight, that of any of the diamond bearing (lherzolitic)
kimberlites in the C.F. Minerals database. These results indicate that large diamonds should be
present if sufficiently large tonnages of this kimberlite are processed by methodology that
recovers large diamonds. The presence of abundant diamond inclusion chromites and
orthopyroxenes, as well as abundant diamond inclusion Group 1 eclogitic garnets, and
subordinate low calcium-high chrome G10 garnets and diamond inclusion olivines indicate
smaller potentially commercial diamonds may also be present.”
Table 1 – Caustic Fusion Results, Sequoia Kimberlite, Arctic Star
Drill
hole
0.105mm 0.15mm 0.212mm 0.3m
m
0.425m
m
0.6m
m
0.85m
m
Weig
ht
Kg
Total
stone
s
Stone
s/100
kg
Sequoi
a Total
146 54 11 7 4 2 0 292.6
0
224 76
Table 2 – Historic Caustic fusion Results, Jack Pine Kimberlite, Drilled by De Beers 1990s
Drill
hole
0.105mm 0.15mm 0.212mm 0.3m
m
0.425m
m
0.6m
m
0.85m
m
Weig
ht
Kg
Total
stone
s
Stone
s/100
kg
Jack
Pine
257 112 37 10 2 0 0 796.0
1
418 52
Figure 1 – Size Frequency plot: Diamond size distribution. Note Sequoia is Orange and Jack
Pine in Green. The Sequoia samples appear to have two populations of diamonds and clearly
have a higher frequency of larger diamonds than the Jack Pine sample. Figure 1 also depicts
possible trajectories for the Sequoia diamond distribution. For this small sample of less than
300kg, the spread of trajectories is large. Further caustic fusion samples would narrow down
this spread. It is desirable to have several commercial size stones from caustic fusion before
predicting grade and size distribution with great accuracy.
Dotted lines are projections.
Current results suggest a
1 carat stone every 5t - 100t,
More Caustic fusion results
will tighten this spread and
allow the design of a bulk
sample to demonstrate the
occurrence of large stones
Sequoia
Jack Pine
Commercial sized stones
Table 3 below shows the geology of drill hole DG 2021 04 and each individual rock type and
Caustic fusion diamond count for stones over 105 microns, illustrating the diamond count
differences, which will be reflected in the commercial grade. The next round of work will outline
the distribution of these rock types while continuing to make a more robust size frequency curve.
From To Interval Geology Diamond count
0m 28m 28m Overburden Not assayed
28m 51.29m 51.29m RVK 68/100 kg
51.29m 89.38m 37.95m CK 132/100kg
89.38m 101.26m 11.88m VKt 45/100kg
101.26 105.25m 3.99m CK 150/100kg
105.25m 123.49m 18.34m VKt 46/100kg
123.49m 154m 30.51m VK 56/100kg
The table demonstrates different kimberlite types have variable diamond counts. Volcanoclastic
rock types have significantly less diamonds than the coherent kimberlite rock type (Results are
from Caustic fusion SRC laboratories and an independent laboratory – see news release dated
July 6th 2021 for details).
Analysis of mineral indicator minerals from the other kimberlites is awaited. The rest of the
caustic fusion diamond results from the other kimberlite discoveries are expected before the end
of this week. The second round of Sequoia results where Arctic Star has sampled the other half
of drill holes DG 2021 04 and 05 should also be in, within the next few weeks.
Qualified Person
The Qualified Person for this news release is Buddy Doyle, AUSIMM, a Geologist that is
employed by and works for Arctic Star with over 35 years’ experience in diamond exploration,
discovery, and evaluation. A Qualified Person under the provisions of National Instrument 43-
101.
Contact Information
Neil Foran
Chief Executive Officer
(604) 681-7735
Forward-Looking Statements
This press release contains forward -looking information or forward -looking statements
(collectively "forward -looking information") within the meaning of applicable securities laws.
Forward-looking information is typically identified by words such as: "beli eve", "expect",
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performance, and that actual results may differ materially from those in forward -looking
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filings for a more complete discussion of such risk factors and their potential effects, which
may be accessed through the Company's profile on SEDAR at www.sedar.com .