Tom Larsen reports
ELORO RESOURCES' FIRST DRILL HOLE AT THE ISKA ISKA PROJECT'S CENTRAL BRECCIA PIPE ENCOUNTERS MULTIPLE MINERALIZED INTERCEPTS INCLUDING 196 GRAMS SILVER EQUIVALENT/TONNE (G AG EQ/T) OVER 56.2M AND CONTAINING 343 G AG EQ/T (274 G AG/T, 0.16% SN AND 0.16 G AU/T) OVER 27.5M
Eloro Resources Ltd. has provided an update on its Iska Iska silver-tin polymetallic project in Potosi department, southern Bolivia. To date, the company has completed 29 diamond drill holes totalling 11,696 metres to test the Huayra Kasa mine area and the Santa Barbara breccia pipe (SBBP) and Central breccia pipe (CBP) targets. This press release reports further drilling results from the first drill hole (CDN-01) to test the CBP from the northern radial platform. An image on the company's website is a geological plan map showing locations of the drill holes and updated geological interpretation. Another image on the company's website is a northeast-southwest geological cross-section through the eastern side of the SBBP and the northwest part of the CBP, showing the location of the main mineralized zone. A table on the company's website gives significant drilling results, and another table on the company's website lists holes completed with assays pending. Highlights are as follows:
Hole DCN-01 intersected multiple mineralized intercepts including 196.09 grams per tonne silver equivalent (150.25 g/t silver, 0.10 per cent tin and 0.05 g/t gold) over 56.2 m and containing 342.98 g/t AgEq (274.0 g/t Ag, 0.16 per cent Sn and 0.16 g/t Au) over 27.53 m, from 252.84 m to 309.04 m in hole DCN-01.
- Recently completed hole DSB-10, drilled from a platform at the SBBP, encountered over 500 m of continuous sulphide mineralization in a position several hundred metres below mineralization encountered in hole DCN-01. Assays are pending.
Major mineralized zone being outlined in Central breccia pipe
Drill hole DCN-01, drilled from the northern radial set-up on the CBP, intersected a broad 483.3 m wide mineralized zone, from 107.2 m to the end of the hole at 590.5 m. Within this mineralized zone there are 19 intersections greater than 31 g/t AgEq, representing 61 per cent of the overall mineralized interval, including eight intersections greater than 60 g/t AgEq. The highest-grade interval returned 196.09 g/t AgEq (150.25 g/t Ag, 0.10 per cent Sn and 0.05 g/t Au) over 56.2 m, including 342.98 g/t AgEq (274.0 g/t Ag, 0.16 per cent Sn and 0.16 g/t Au) over 27.53 m from 252.84 m to 309.04 m. As shown in an image on the company's website and discussed below, this intersection appears to be the top of a very extensive mineralized zone in the CBP that may be as much as 500 m thick.
Drill hole DSB-10, drilled on an azimuth of 225 degrees at a dip of minus 60 degrees, initially intersected 380 m of oxidized and leached breccia of the SBBP before intersecting a 500 m long section of mineralized intrusion breccia in the northwestern part of the CBP, as shown in images on the company's website. Within this broad zone, moderate to strong sulphide mineralization extends for a total of 293 m from 522 m to 586 m (64 m) and from 650 m to 879 m (229 m). This hole is the longest drilled at Iska Iska thus far, with a final length of 1,019.4 m, reflecting the remarkable size of the mineralized system in the CBP. Drill hole DCN-02, drilled on section with DCN-01 to the southwest at minus 60 degrees, intersected several zones of mineralized intrusion breccia approximately 50 m thick before intersecting dacite at the western margin of the breccia pipe. DCN-03 was drilled from the same set-up at minus 60 degrees to the southeast for a length of 464.5 m but was stopped in favour of doing a more efficient hole from the southern radial set-up. This hole, at an azimuth of 90 degrees and a dip of minus 60 degrees, is currently at 780 m and is continuing. Assay results from all these holes are pending. Further drilling is planned to better define the overall mineralized zone, which is very extensive.
Third and fourth diamond drills being mobilized to Iska Iska site
Eloro contractor Leduc Drilling has mobilized a high-capacity underground drill to Iska Iska, which is capable of drilling up to 600 m long underground drill holes. This drill is currently being set up in drill bay No. 3 at the west end of the Huayra Kasa underground workings to complete a fan of holes to evaluate the area beneath the Santa Barbara adit eastward to the centre of the caldera complex. The first hole, DHK-18, to be drilled at an azimuth of 180 degrees and dip of minus 10 degrees, will be collared shortly. This hole is designed to test underneath the Santa Barbara adit where a recent continuous channel sample returned 442 g/t AgEq (165 g/t Ag, 3.46 per cent Pb and 0.46 per cent Sn) over 166 m including 1,092 g/t AgEq (including 446 g/t Ag, 9.03 per cent Pb and 1.16 per cent Sn) over 56.19 m (see press release dated April 13, 2021). An underground drill bay will also be excavated at the west end of the Santa Barbara adit to allow underground drilling from there. Underground drilling is also possible from the Porco adit.
As previously announced (see press release March 29, 2021), an additional surface drill will be mobilized in early May to test the Porco target, located in the southern part of the Iska Iska caldera complex. This will be the fourth drill on site.
Geophysical, metallurgical, synchrotron and mineralogical studies
The magnetic survey is progressing well with approximately 43 per cent of the planned 185-line-kilometre survey now complete. Continuous readings are being taken on north-south lines spaced at 50 m intervals to provide detailed magnetic coverage of the entire property. Downhole induced polarization (IP) surveys and a surface gradient IP survey are also planned.
Preliminary metallurgical tests are in progress at the university laboratory in Oruro. Results from the synchrotron study by Western University are currently being analyzed. Mineralogical studies are in progress at the Colorado School of Mines.
Micon International retained to complete updated National Instrument 43-101 technical report
Charley Murahwi, PGeo, senior economic geologist for Micon International Ltd. and an independent technical consultant for Eloro, previously completed an independent National Instrument 43-101 technical report on Iska Iska, dated April 27, 2020, which included a site visit in January, 2020. Mr. Murahwi is currently updating this report to reflect drill hole results reported up to and including this news release. While COVID-19-related travel restrictions have prevented a return site visit, Mr. Murahwi has been kept up to date on the program's progress and has had the opportunity to view a number of representative drill hole samples as well as review all drill hole data.
Tom Larsen, chairman and chief executive officer of Eloro, said: "As the technical team receive more geological information and assay results from the accelerated drilling program, it is becoming readily apparent that Iska Iska is proving to be in a massive mineralized system generating elevated metal values from every host rock and structure encountered, especially as one goes deeper. Results from our discovery hole DHK-15, the recent channel sampling of the Santa Barbara adit and current results from hole DCN-01 show the significant potential for outlining major areas of high-grade mineralization within this extensive mineralized system."
Dr. Bill Pearson, PGeo, Eloro's executive vice-president, exploration, stated: "We are continuing to aggressively explore the very extensive mineralized system at Iska Iska. The target area for mineralization in SBBP and CBP is now more than one km long and at least 800 m wide with mineralization open in all directions. All of the holes drilled to date have intersected mineralization. The recognition of the importance of the third stage of major remobilization by Dr. Arce, as outlined in our April 13, 2021, release, has opened up large areas for further testing outside of the immediate breccia pipes, which themselves are major targets. The addition of our third and fourth drills will allow us to continue to aggressively test these targets. We also very much hope that the COVID-19 situation in Lima, Peru, will improve so that the ALS global laboratory can return to more normal production rates for assaying."
Dr. Quinton Hennigh, PGeo, commented: "Every single drill hole completed at Iska Iska to date has encountered mineralization, a very positive sign that we are dealing with a very large system. While it is remarkable to see the first hole at CBP return multiple intervals of mineralization, some high grade, it is also intriguing that hole DSB-10 has encountered over 500 m of continuous sulphide mineralization several hundred metres below. What was encountered in hole DCN-01 may simply be smoke above something even larger. We are quite anxious to see the return of results from this hole."
Dr. Osvaldo Arce, PGeo, general manager of Eloro's Bolivian subsidiary, Minera Tupiza SRL, and an expert on Bolivian geology, stated: "The style, metal types and distribution of mineralization at Iska Iska are very typical of the Bolivian polymetallic type of deposit. What is remarkable at Iska Iska, however, is that the entire system is so well preserved. In recent drill holes such as DSB-10, we are intersecting extensive thicknesses of sulphide mineralization that are comparable in scale to other well-known world-class Bolivian polymetallic deposits. Multiepisodic activities of magmatic-hydrothermal systems within different host lithologies and structures lead to multistage polymetallic mineralization. Sn and Ag typically characterize the first-stage inner high-temperature part of a kilometre-sized mineralizing system with sulphide breccias, veins, stockworks and disseminations centred in both an intrusion breccia cupola and the overlying subvolcanic granodiorite intrusion at the CBP.
"Subsequent second-stage mineralization sequentially expanded outwards from the intrusion breccia and granodioritic intrusion forming a broader halo with vein breccia or replacement-style Pb-Zn plus or minus Sn plus or minus Au plus or minus Bi plus or minus Cu polymetallic-stage mineralization hosted in breccia pipes and dacitic domes of a lower-temperature shallower epithermal system at the SBBP. This produced different types of enriched mineralized shoots within the breccia and the dacitic envelope. The remarkable tin and/or silver-polymetallic-enriched zones such as in hole DCN-01, DSB-10 and the Santa Barbara adit likely formed in the third phase due to faulting and fracturing during major Andean deformation, which led to development of favourable sites for redeposition and remobilization/upgrading of the pre-existing tin and silver-polymetallic mineralization. This last stage was likely a prolonged multistage event with considerable telescoping of mineralization."
True width of the mineralization is not known at the present time, but based on the current understanding of the relationship between drill orientation/inclination and the mineralization within the breccia pipes and the host rocks such as sandstones and dacites, it is estimated that true width ranges between 70 per cent and 90 per cent of the downhole interval length but this will be confirmed by further drilling. Percentage metal contents are shown for each element.
Metal prices and conversion factors used for calculation of g/t AgEq (grams Ag per grams times metal) are shown in the associated table.
Element Price Ratio to Ag
Ag $875.00 1.00000
Sn $28.00 0.03200
Zn $2.80 0.00320
Pb $2.10 0.00240
Au $57,400.00 65.60000
Cu $8.80 0.01006
Bi $12.76 0.01458
In $305.00 0.34857
Cd $5.50 0.00629
In calculating the intersections reported in this press release a sample cut-off of 30 g/t AgEq was used with generally a maximum dilution of three continuous samples below cut-off included within a mineralized section unless more dilution is justified geologically.
Total drilling completed since the start of the program on Sept. 13, 2020, is 11,696.4 m in 12 underground holes and 17 surface holes with one underground and two surface holes in progress.
Dr. Arce, a qualified person in the context of National Instrument 43-101, has reviewed and approved the technical content of this news release. Dr. Pearson, who has more than 45 years of worldwide mining exploration experience including extensive work in South America, manages the overall technical program in consultation with Dr. Hennigh and independent technical adviser Charley Murahwi, PGeo, FAusIMM, of Micon International.
Drill and channel samples are prepared in ALS Bolivia Ltda.'s preparation facility in Oruro, Bolivia, with pulps sent to the main ALS laboratory in Lima for analysis. As announced in the Feb. 26, 2021, press release, Eloro has changed the assay protocol to utilize X-ray fluorescence (XRF) to more accurately analyze higher Sn. Tin in the CBP is suspected to occur as cassiterite, which is insoluble in acid digestion and therefore not suited for wet chemical techniques. In addition, other assay protocols have been changed to provide for a more accurate measurement of the wide-ranging suite of polymetallic metals at Iska Iska. Eloro employs an industry-standard quality assurance/quality control program with standards, blanks and duplicates inserted into each batch of samples analyzed with selected check samples sent to a separate accredited laboratory.
Unfortunately, the ALS laboratory in Lima where the Iska Iska samples are being analyzed has had major delays in turnaround time due to the impact of the COVID-19 lockdown of Lima by the Peruvian government. This has restricted availability of critical supplies necessary to carry out analytical work. As a result, there will be delays in reporting of assay results.
About Iska Iska
The Iska Iska silver polymetallic project is a road-accessible, royalty-free property, wholly controlled by the title holder, Empresa Minera Villegas SRL, and is located 48 km north of Tupiza city, in the Sud Chichas province of the department of Potosi. The property can be classified as a silver polymetallic (silver, zinc, lead, gold, copper, bismuth, tin and indium) and porphyry-epithermal complex. This is an important mineral deposit type in the prolific South mineral belt of Bolivia.
Silver-tin polymetallic mineralization at Iska Iska occurs within a Miocene possibly collapsed/resurgent caldera that consists of granodioritic stocks and five dacitic domes, which are each about 500 m in diameter. These rocks intrude/extrude an intensely deformed sequence of Ordovician shales, siltstones and sandstones, which are partially covered by Miocene pyroclastic rocks. The silver polymetallic mineralization occurs mainly as veins, vein swarms, veinlets, stockworks, disseminations and in breccias associated with intense hydrothermal alteration. The Iska Iska dome complex has several major phases of igneous breccias, quartz porphyries, dikes and dacitic syn-kinematic flows.
On Nov. 18, 2020, Eloro announced the discovery of a significant breccia pipe with extensive silver polymetallic mineralization just east of the Huayra Kasa underground workings and a high-grade gold-bismuth zone in the underground workings. Diamond drilling intersected a number of extensive mineralized intersections within the major breccia pipe including 54.48 g/t Ag, 1.45 per cent zinc (Zn) and 1.60 per cent lead (Pb) over 16.39 m (140.91 g/t AgEq) within a broader interval of 122.74 m grading 14.29 g/t Ag, 0.81 per cent Zn and 0.41 per cent Pb (53.67 g/t AgEq) in hole DHK-04 (see press release dated Nov. 18, 2020).
The high-grade gold-bismuth zone outlined in channel samples in the underground working averaged 7.1 g/t Au and 0.2 per cent Bi (8.29 g/t AuEq) over 3.04 m width for strike length of 47 m. Hole DHK-05 on the strike extension of the high-grade Au-Bi zone intersected 6.51 g/t Au, 0.07 per cent Bi and 31.96 g/t Ag (7.68 g/t AuEq) over 11.85 m including 29.56 g/t Au, 0.26 per cent Bi and 63.69 g/t Ag (31.94 g/t AuEq) over 2.31 m in this high-grade zone.
On Jan. 26, 2021, Eloro announced significant results from drilling at the Santa Barbara breccia pipe. Highlights are as follows:
- 129.60 g/t AgEq over 257.5 m (29.53 g/t Ag, 0.078 g/t Au, 1.45 per cent Zn, 0.59 per cent Pb, 0.080 per cent Cu, 0.056 per cent Sn, 0.0022 per cent indium, 0.0064 per cent bismuth and 0.0083 per cent cadmium) from 0.0 m to 257.5 m in hole DHK-15, the deepest of the three holes reported within the SBBP;
- 79.00 g/t AgEq over 121.33 m (21.77 g/t Ag, 0.034 g/t Au, 0.35 per cent Zn, 0.23 per cent Pb, 0.18 per cent Cu, 0.056 per cent Sn, 0.0011 per cent In, 0.004 per cent Bi and 0.0055 per cent Cd) from 0.0 m to 121.33 m in hole DHK-14 within the SBBP;
- 74.16 g/t AgEq over 40.88 m (33.43 g/t Ag, 0.032 g/t Au, 0.04 per cent Zn, 0.33 per cent Pb, 0.13 per cent Cu, 0.045 per cent Sn, 0.0010 per cent In and 0.0012 per cent Bi) from 30.40 m to 71.28 m in hole DHK-13, which is within the approximately 100 m wide mineralized envelope that surrounds the breccia pipe.
Silver-tin polymetallic mineralization within the Iska Iska system occurs over a potential strike length of more than 2.5 km along major ring structures in the caldera complex. A synchrotron study of the underground channel samples (see press release dated June 25, 2020) concluded that the mineral cluster analysis identified four mineralogical domains that cover the entire sampling area suggesting they are related and represent a single, large mineralizing system. Furthermore, the mineralogy of the domains is consistent with minerals identified in hand specimen and is likely related to a telescoped porphyry/epithermal style of mineralization.
About Eloro Resources Ltd.
Eloro is an exploration and mine development company with a portfolio of gold and base metal properties in Bolivia, Peru and Quebec. Eloro has an option to acquire a 99-per-cent interest in the highly prospective Iska Iska property, which can be classified as a polymetallic epithermal-porphyry complex, a significant mineral deposit type in the Potosi department, in southern Bolivia. Eloro commissioned a National Instrument 43-101 technical report on Iska Iska, which was completed by Micon International and is available on Eloro's website and under its filings on SEDAR. Iska Iska is a road-accessible, royalty-free property.
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