Arctic Provides Details of the Sequoia Kimberlite
Highlights
-
- Core logging of the two drill holes reveals contrasting kimberlite types.
- Each kimberlite type has indicator minerals, all have the potential to contain diamond.
- The volcanoclastic kimberlite and the coherent kimberlite types are considered to have the best diamond potential.
- 40 samples totaling 306 kg have been sent to the laboratory for caustic fusion diamond analysis. Once the samples are processed the laboratory will release the results.
June 28, 2021 – TheNewswire - Vancouver, British Columbia – Arctic Star Exploration Corp. (“Arctic Star” or the “Company”) (TSXV:ADD) (Frankfurt:82A2) (WKN:A2DFY5) (OTC:ASDZF) is pleased to report the more detailed geological logs for the Sequoia kimberlite. The core has been logged in Yellowknife by Dan Gainer, P. Geo. A geologist who is knowledgeable in kimberlite geology.
The Sequoia kimberlite is thought to be a number of kimberlite intrusive and volcanic events that have coalesced into an approximately 1 km long and 200 m wide kimberlite complex. Arctic drilled two holes 232 m apart into different sectors of a gravity low (less dense) and resistivity (more conductive) geophysical anomaly, interpreted as mapping the complex. The holes intersected contrasting kimberlite types confirming the complex consists of multiple volcanic events. Each volcanic event can have different diamond grades and in some cases different diamond qualities (average values).
Table 1 summarizes the geology from the two Sequoia drill holes. Kimberlites are relatively small volume volcanoes and volcanic rock terms are applied to describing the different rock types. The term Volcanoclastic means that this rock was formed relatively near surface and that the material was part of probably explosive eruption. They are fragmental rocks and the matrix consists of either muds derived from the surface or ash derived from the eruption, or combinations of these. Often the fragments are dominated by the local country rock the kimberlite intruded into. Kimberlite clasts also occur along with crystals (xenocrysts) from the mantle and the kimberlite melt.
The term Coherent kimberlite describes a fragmental rock where kimberlite fragments dominate, the matrix consists of kimberlite. This rock type is thought to be intrusive or extrusive.
Kimberlite core observations and geological interpretations can estimate the potential for each particular rock type to carry commercial (>1mm diameter) diamonds. Rock types that are fine grained, grains size <1mm have a low potential. Rock types where >1mm crystals and kimberlite fragments dominate have higher potential.
Other visual aspects of the core are the presence and abundance of indicator minerals. Diamonds are formed at >150km depth and under great pressure and subsequently brought to the surface via the eruptive kimberlite event. Along with diamonds and in 2 to 3 orders of greater abundance come other unique minerals (indicator minerals), as they are also formed under high pressure. Indicator minerals were noted in all the rock types observed in the two Sequoia drill holes. The Coherent kimberlite and the lower Volcanoclastic kimberlite are thought to have the best diamond potential due to the abundance of indicator minerals and the coarse grain size. There are other aspects that control the diamond content so it needs to be noted that a rock that is considered to have high potential will not necessarily contain economic amounts of diamonds.
Table 1 Summarizes the geology from the Sequoia kimberlite hole, DG-2021-04
Drill Hole |
From |
To |
Interval |
Geology |
DG-2021-04 |
0m |
28m |
28m |
Overburden |
28m |
51.29m |
23.29m |
Resedimented Volcanoclastic Kimberlite (RVK) |
|
51.28m |
89.38m |
37.95m |
Coherent Kimberlite (CK) |
|
89.38m |
101.26m |
11.88m |
Volcanoclastic Kimberlite transitional into Coherent Kimberlite. (VKt) |
|
101.26m |
105.25m |
3.99m |
Coherent Kimberlite (CK) |
|
105.25m |
123.49m |
18.34m |
Transitional Volcanoclastic Kimberlite. (VKt) |
|
123.49m |
154m |
30.51m |
Volcanoclastic Kimberlite (VK) |
A total of 126m of kimberlite, 18% RVK, 33% CK, 24% VKt, 25% VK.
Table 2 Geological summary of the kimberlite in Drill hole DG 2021-05
Drill Hole |
From |
To |
Interval |
Geology |
DG-2021-05 |
0m |
16.8m |
16.8 m |
Overburden |
16.8m |
33.53m |
16.73 m |
Granite |
|
33.53m |
53.7m |
37.95m |
Volcanoclastic Kimberlite (VK) |
|
53.7m |
63.35m |
9.65m |
Altered Kimberlite (AK) |
|
63.35m |
83.39m |
20.04m |
Coherent Kimberlite (CK) |
|
83.39m |
94.45m |
11m |
Granite |
A total of 66.59m of kimberlite, 57% VK, 30% CK, 13% AK.
The NQ size kimberlite drill core was mechanically split and sent to SRC laboratory in Saskatoon. Samples were sent in 8 kg charges (which represent approximately 4.3m of core separated by geology where possible). Table 3 lists the samples sent for the Sequoia kimberlite. Once all the samples from each kimberlite are processed, the laboratory will release the results.
Table 3.
Drill Hole |
No of Samples |
Weight |
DG2021-04 |
30 |
229.45 |
DG202105 |
10 |
76.63 |
Total 306.08kg, 40 samples.
The following figures give examples of the kimberlite types and indicator minerals found at the Sequoia kimberlite.
Figure 1: An example of a mantle nodule from the Sequoia kimberlite, Drill hole DG-2021-05, light green olivine, apple green chrome diopside.
Figure 2: An example of Volcanoclasitc kimberlite from, DG-2021-04.
Figure 3: Coherent kimberlite, DG-2021-04
Figure 4: Volcanoclstic Kimberlite from DG-2021-05 on the left and the altered kimberlite of the right. The altered kimberlite is most likely a transitional to Coherent kimberlite. This type of alteration would not be diamond destructive.
Qualified Person
The Qualified Person for this news release is Buddy Doyle, AUSIMM, a Geologist of over 35 years’ experience in diamond exploration, discovery, and evaluation. A Qualified Person under the provisions of National Instrument 43-101.
About Arctic Star
Arctic Star has commenced exploration in Lac de Gras NWT on its Diagras Diamond Project next to the producing Diavik & Ekati diamond mines. The Company also owns 100% of the Timantti Diamond Project including a 243 Ha Exploration Permit and a 193,700 Ha Exploration Reservation near the town of Kuusamo, in Finland. The project is located approximately 550km SW of the operating Grib Diamond Mine in Russia. The Company also controls drill ready diamond exploration properties in Nunavut (Stein).
ON BEHALF OF THE BOARD OF DIRECTORS OF ARCTIC STAR EXPLORATION CORP.
Patrick Power, President & CEO
+1 (604) 218-8772
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Cautionary Statement Regarding “Forward-Looking” Information
This news release contains “forward-looking statements” including but not limited to statements with respect to Arctic Star’s plans, the estimation of a mineral resource and the success of exploration activities. In this release it is not certain if the kimberlite discovered will be economic or not as this depends on many factors. Forward-looking statements, while based on management’s best estimates and assumptions, are subject to risks and uncertainties that may cause actual results to be materially different from those expressed or implied by such forward-looking statements. There can be no assurance that such statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Factors that could affect our plans include our potential inability to raise funds as intended, and in such event we may require all funds raised, if any, to be used for working capital rather than the intended uses as outlined. Accordingly, readers should not place undue reliance on forward‐looking statements. Arctic Star undertakes no obligation or responsibility to update forward‐looking statements, except as required by law.