The Sugar Zone Property is located 30 km northeast of the town of White River in northern Ontario. White River is located on Trans-Canada Highway 17 approximately midway between Thunder Bay, 315 km west, and Sault Ste. Marie, 260 km southeast. The Operation is approximately 715 km northwest of Toronto and 68 km east of the Hemlo Gold Camp, Ontario.
The Sugar Zone Deposit is located in UTM Zone 16UNAD83 at 646,140 m E, 5,406,900 m N or 48° 47' 53" North latitude and 85° 00' 36" West longitude. The overall Property encompasses NTS Zones 42C/ 10, 11, 14 and 15 and covers portions of Odium, Strickland, Gourlay, Tedder, Abraham Bayfield, Cooper, Johns, Nameigos, Mosambik and Hambleton Townships and falls within the Sault Ste.
History
The Sugar Zone Property has a history of significant exploration that has been undertaken intermittently since 1969. The majority of the work has been done in the vicinity of Dayohessarah Lake and the Sugar Zone area and follows the discovery of the Hemlo Gold Deposit in 1981. Hemlo Gold Mines Inc. discovered the Sugar Zone Deposit by surface prospecting in 1991, followed by trenching and diamond drilling between 1991 and 1994. The Property was explored by the Corona Gold Corporation/Harte Gold Corp. Joint Venture between 1998 and 2009 and subsequently by Harte Gold after 2010. To date there have been 995 holes drilled for a total of 349,721 m on the Property.
Harte Gold completed a 70,000 t underground bulk sampling program on the Sugar Zone in 2017. The program included approximately 960 m of ramp development and 634 m of horizontal drifting in mineralization on five levels at a 15 m vertical spacing, to provide drilling access for long hole mining. A total of 15 stopes were mined from development work completed on the 375, 360, 345, 330 and 315 metres above sea level ("masl") Levels. An extensive sampling and grade control program was completed which included chip, miner muck, crusher muck and truck muck sampling. Toll processing of the bulk sample was completed at Barrick's Williams Mine process plant located in the Hemlo camp. Overall, the combined development and production mineralization from the block model was estimated by Harte Gold at a gold grade of 7.25 g/t Au compared to a processed and stockpile grade of 7.55 g/t Au, resulting in an underestimation of the Mineral Resource grade by Harte Gold of 0.30 g/t Au or 4.1%.
All commercial production permits were issued in September 2018. Process plant construction and transition to electric grid power were completed in September 2018, with the first gold bar poured in October 2018. Process plant commissioning was completed in early November 2018. An official mine opening was attended by the Premier of Ontario and Minister of Energy, Northern Development and Mines on October 24, 2018. The first production blast was completed in the mine in early November 2018.
The Company bought down the royalty on the Sugar Zone Property from 3.5% to 2.0% effective October 31, 2018.
Summary of Exploration History of the Sugar Zone Property Area
1998. Corona Gold Corporation (51%)andHarte Gold Corp. (49%) Joint Venture. Corona-Harte Gold JV options Property.
1998-1999. Corona-Harte Gold JV. 53 NQ diamond drill holes totalling 9,922 m cover 3 km strike length on Sugar Zone at 50 m spacing and test IP anomalies west of Sugar Zone and east of Dayohessarah Lake. Power trenching on Sugar Zone with six trenches excavated, mapped and sampled. 96 km of grid with lines at 100 m cut on Sugar Zone with mapping, rock and soil sampling. Detailed Mag VLF and reconnaissance gradient IP survey were completed.
2003-2004. Corona-Harte Gold JV. Step-out and infill diamond drilling on the Sugar Zone with 26 holes for a total of 7,100 m.
2004. Corona-Harte Gold JV. Further step-out and infill diamond drilling on the Sugar Zone with 12 holes for a total of 3,563 m.
2008. Corona-Harte Gold JV. 1,917 line km DIGHEM/mag airborne survey flown by Fugro Airborne Surveys Corp.
2009. Corona-Harte Gold JV. Diamond drilling program totalling 2,007 m in 10 holes. Program tests airborne EM and magnetic anomalies, plus IP chargeability anomalies and geologically defined targets to the north and the south of the known Sugar Zone mineralization. Prospecting, reconnaissance geological mapping and channel sampling program was completed to evaluate Fugro airborne anomalies. Highlights included sampling of a float rock returning a value of 87.80 g/t Au, as well as grab samples from quartz veining east of the Sugar Zone returning values of 30.40 and 9.04 g/t Au.
2010. Harte Gold Corp. First Harte Gold Corp. drilling program. 12 holes totalling 2,097 m.
Information on the Hemlo Gold Mines Inc. ("Hemlo Gold") and Corona-Harte Gold JV programs in the following paragraphs is from Hunt (2010) and Kociumbas and Power-Fardy (2012).
Hemlo Gold Mines Inc. ("Hemlo Gold") drilled six diamond drill holes targeting the Sugar Zone between September 17 and September 25, 1993. 15 more diamond drill holes were completed between September and October, 1994, by Hemlo Gold, of which nine targeted the Sugar Zone. The drilling was done by Chibougamau Diamond Drilling Inc. All diamond drill holes were NQ sized. The diamond drill core from within the Sugar Zone is currently being stored at the Harte Gold core logging facility in White River, Ontario and the rest of the core is currently stored in pallets along Road 305, north of the Sugar Zone.
All of the Hemlo Gold core samples were sent to Chemex Laboratories Ltd., which became ALS Chemex Laboratories Ltd., and more recently known as ALS Minerals Ltd. ("ALS"), Vancouver, B.C. All samples were assayed for gold using a fire assay using lead collection and an AAS finish. All drill hole collars were spotted in reference to the nearest picket on a cut grid with 100 m spaced lines oriented at 50°. Kociumbas and Power-Fardy (2012) report that there is no information on how or if down-hole surveys were completed. The drill hole collars were located and recorded by Harte Gold personnel with a Trimble 3000 GeoXT, in December of 2011, in order to locate the drill collars with sub-metre accuracy.
A total of 100 NQ diamond drill holes were drilled by Corona over three diamond drill program phases between 1998 and 2009. All of the drilling was carried out by Chibougamau Diamond Drilling, QC. Field supervision and logging for all four diamond drill programs were mostly carried out by David S. Hunt, P.Geo., of Sharpstone. The diamond drill core prior to 2009 from the within the Sugar Zone is currently being stored at the Harte Gold drill core logging facility in White River, Ontario. The remainder of the core is currently stored in pallets along Road 305, north of the Sugar Zone. All diamond drill core from the 2009 program is currently stored at the core logging facility in White River. All core samples were sent to Accurassay Laboratories in Thunder Bay, Ontario.
All drill hole collars were spotted in reference to the nearest grid line picket. The drill hole collars were located and recorded by Harte Gold personnel with a Trimble 3000 GeoXT, in December of 2011, in order to locate the drill collars with sub-metre accuracy. The drill was oriented using a Brunton compass by the supervising geologist, and down-hole surveys were taken at 50 m intervals using a Reflex EZ Shot single shot unit by the drillers.
Regional geology
The Dayohessarah Greenstone Belt of late Archean (ca. 2.7 Ga) age is located in the AbitibiWawa Subprovince of the Superior Province. The Dayohessarah Belt is positioned between two larger greenstone belts; the Hemlo Belt to the west and the Kabinakagami Belt to the east. The Dayohessarah Greenstone Belt trends broadly north and forms a narrow, eastward concave crescent. The belt is approximately 36 km in length and varies in width from 1.5 to 5.5 km. Principal lithologies in the belt are moderately to highly deformed metamorphosed volcanics, volcanoclastics and sediments that have been enclosed and intruded by tonalitic to granodioritic quartz-porphyry plutons.
The greenstone belt is bordered to the east by the Strickland Pluton and to the west by the Black Pic Batholith. The Danny Lake Stock borders the south western edge of the Dayohessarah Greenstone Belt. The Strickland Pluton is characterized by a granodioritic composition, quartz phenocrysts, fine-grained titanite, and hematitic fractures. The Black Pic Batholith is similar to the Strickland Pluton, but locally more potassic with monzogranite phases. The Danny Lake Stock is characterized by hornblende porphyritic quartz monzonite to quartz monzodiorite (Stott, 1999).
The Dayohessarah Greenstone Belt has been metamorphosed to upper greenschist to amphibolite facies. The Strickland Pluton seems to have been emplaced into the greenstone belt and imposed a thermal metamorphic event. Most of the mafic volcanics are composed primarily of plagioclase and hornblende. Almandine garnets are widely observed in the clastic metasediments and locally pyrope garnets are present in the mafic metavolcanics (Stott, 1996).
Alteration throughout the belt consists of diopsidation, albitization, weak magnesium biotization, weak carbonatization and moderate to strong silicification that accompanied the emplacement of the porphyry dykes/sills and quartz veining. The belt has been strongly foliated, flattened and strained. Deformation seen in the supracrustal rocks has been interpreted to be related to the emplacement of the Strickland Pluton. Strongly developed metamorphic mineral lineations in the supracrustal rocks closely compare with the orientations of the quartz phenocryst lineations seen in the Strickland Pluton. This probably reflects a constant strain aureole imposed by the pluton upon the belt (Stott, 1996). The strain fabric is best observed a few hundred metres from the Strickland Pluton in the Sugar Zone, which has been characterized as the most intensely strained part of the belt. The Sugar Zone is defined by sets of parallel mineralized quartz veining, quartz flooding of strongly altered wall rock, thin intermediate porphyry lenses and dykes/sills parallel to stratigraphy and foliation, and gold mineralization.
Stratigraphic layering and top indicators define a synclinal fold in the central portion of the belt. The synclinal fold has been strongly flattened and stands upright with the fold hinge open to the south and centered along Dayohessarah Lake.
Regional geology map
Sugar zone geology
Near Dayohessarah Lake, the belt is dominated by a basal sequence of massive to pillowed mafic volcanics, commonly with ellipsoidal, bleached alteration pods, overlain by intermediate tuff and lapilli tuff. The tuffaceous units rapidly grade upwards to a sedimentary sequence consisting of greywacke and conglomerates derived from volcanics, sediments and felsic intrusive sources (Stott, 1996). Several thin, continuous cherty sulphide facies iron formations are found in the mafic volcanic sequence. Spinifex textured komatiitic flows stratigraphically underlie the main sedimentary sequence and can be traced around the north end of Dayohessarah Lake. Also at the north end of Dayohessarah Lake, mafic and ultramafic sills and stocks underlie the komatiites.
Numerous fine- to medium-grained, intermediate feldspar porphyry dykes and sills have intruded the metavolcanic and metasedimentary rocks and form an intrusive swarm. The intrusions of the intermediate porphyry dykes are most intense east of Dayohessarah Lake. Stott has interpreted the porphyry sills and associated porphyry bodies to be related to the Strickland Pluton. A smaller granitic quartz porphyry body containing some sulphide mineralization is located northwest of Dayohessarah Lake. The porphyritic texture of the dykes/sills is often nearly, or completely, obliterated by the degree of foliation in the greenstone belt, or by the degree of deformation in the Sugar Zone. These intermediate dykes/sills vary in abundance across the Property, but increase in regularity within, and around, the Sugar Zone. There is also a consistent, weak pervasive silicic alteration in the intermediate intrusive rocks, as well as consistently trace amounts of very fine-grained disseminated pyrite.
The major deformation structure recognized on the Property is the Sugar Deformation Zone (“SDZ”) that trends northwest-southeast for approximately 3.5 km and dips west between -65° and -75°. The SDZ appears to be spatially related to the Strickland Pluton and is a complex zone with strain intensities varying from strongly deformed, pillow-mafic volcanics to undeformed massive mafic flows to anastomosing linear zones. Structurally concordant porphyritic intermediate sills form a swarm through the SDZ. Both the mafic volcanics and the intermediate intrusives exhibit moderate linear fabrics along with hydrothermal silicification.
Stretching and foliation of all rock types, except for the later diabase and felsite dykes, increases with proximity to the SDZ. Within and adjacent to the SDZ, basalt flows are foliated and stretched to the point where primary textures become unrecognizable. Widespread ‘mafic agglomerate’ noted in early exploration on the Property has more recently been interpreted as highly stretched pillowed flows. Within, and proximal to the mineralized zones, boudinage of quartz veins and other brittle features is commonly observed.
White to pale grey, fine- to medium-grained and occasionally pegmatitic felsite dykes intrude the metavolcanic rocks and the mineralization. The dykes are generally narrow, northeast striking and consist of varying amounts of plagioclase, quartz and muscovite. The dykes are undeformed and postdate the mineralization and deformation events.
A northerly-striking, sub-vertically dipping, dark grey-black, weakly magnetic diabase dyke intrudes the older rocks of the greenstone belt, and cuts across the SDZ. The diabase dyke is aphanitic at the contact and grades into a coarse-grained, rock in the dyke center. The dyke contains coarse-grained, greenish feldspar phenocrysts replaced by quartz-epidote up to 3 cm diameter. A small lateral displacement of the Sugar Zones is interpreted locally on either side of the dyke.
Geology of the Sugar zone
Deposit geology
The Upper, Lower and Footwall mineralized subzones range in thickness from 1.5 to 10 m, strike at 140° and dip between 65° and 75° to the west. From west to east, the north-northwest striking lithological units hosting the gold mineralization in the Sugar Zone can be sequentially subdivided as follows:
- Hanging Wall Volcanics;
- Upper Subzone (Sugar Zone mineralization);
- Interzone Volcanics;
- Lower Subzone (Sugar Zone mineralization);
- Interzone Volcanics;
- Footwall Subzone (Sugar Zone mineralization); and
- Footwall Volcanics.
The Hanging Wall, Interzone and Footwall volcanic horizons consist predominantly of massive and pillowed basalt flows generally striking north-northwest and dipping -64° to the west. Coarse to very coarse-grained, locally gabbroic-textured phases form a significant component of the Hanging Wall mafic volcanic package. It is interpreted that these rocks represent portions of massive mafic flows, that grade into finer grained, mafic flows, and eventually to pillowed flows. In much of the area which drilling on the Sugar Zone was carried out, a distinctive, very coarsegrained mafic volcanic flow was observed consistently about 15 m stratigraphically above the Upper Subzone. Other than this unit, specific mafic flows, as well as intermediate porphyry units, are nearly impossible to interpret/distinguish between holes.
The Middle Zone, located along strike between the Sugar and Wolf Zone, shares a similar geological setting, hosted by massive and pillowed basalt flows. Gabbroic-textured flows or sills are as well common. Similar to the Sugar Zone, feldspar porphyry sills often occur adjacent or form part of the mineralized zone. Mineralization styles are similar to that of the Sugar Zone with gold values commonly occurring in quartz veins and veinlets within an altered zone of mafic volcanic and feldspar porphyry.
The auriferous Wolf Zone lies in the northern extent of the SDZ. Similar to the Sugar Zone, the Wolf Zone is north-northwesterly striking, and westerly dipping, however there is only one gold mineralized zone. The Wolf Zone is interpreted as dipping -70o to the west and plunging steeply to the south. Wolf Zone style mineralization is characterized by silicification with fine-grained sulphides and altered porphyry and is interpreted by Harte Gold to have similarities with Hemlostyle mineralization.
Mineralization
The mineralized Upper, Lower and Footwall Subzones of the Sugar Zone lie within the SDZ. They occur within a highly strained assemblage consisting of variously altered mafic volcanic flows, intermediate porphyritic intrusions and boudinaged auriferous quartz veins. The three zones range in true thickness from about 1.5 to 10 m, and are separated by 20 to 30 m of unmineralized metavolcanics.
Each Subzone is made up of one or more porphyritic intrusions, flanked by altered basalt and hosting conformable quartz veins. Alteration within the mafic metavolcanic portions of the subzones consists primarily of silicification that occurs both as pervasive alteration and as quartz veining, diopsidation and biotization. The porphyry units of the zones exhibit biotite and silica alteration, but lack diopside alteration.
The Upper and Lower Subzones appear geologically consistent both down dip and along strike. The Lower Subzone has consistently greater widths, as well as higher grades of gold mineralization. In grade and thickness of both Subzones appear to show consistent correlation along the Sugar Zone. In other words, where the Upper Subzone exhibits greater widths and higher gold grades, the Lower Subzone also exhibits greater widths and higher gold grades. The zones are observed on surface to pinch and swell over distances of 50 m or more.
Gold mineralization mostly occurs in quartz veins, stringers and quartz flooded zones predominantly associated with porphyry zones, porphyry contact zones, hydrothermally altered basalts and, rarely, weakly altered or unaltered basalt within the Upper, Lower and Footwall Subzones.
Fine to coarse-grained specks and blebs of visible gold are common in the Sugar Zone quartz veins, usually occurring within marginal, laminated or refractured portions of the veins. The visible gold itself is often observed to be concentrated within thin fractures, indicating some degree of remobilization. Quartz veins and floods also contain varying amounts of pyrrhotite, pyrite, chalcopyrite, galena, sphalerite, molybdenite and arsenopyrite. The presence of galena, sphalerite and/or arsenopyrite is a strong indicator of the presence of visible gold. Pyrite, chalcopyrite and, rarely, molybdenite form a minor component of total sulphides and do not appear to be directly related to the presence of gold mineralization.
Other mineralized zones have been observed between, above and below the Sugar Zone Upper and Footwall Subzones, in diamond drilling. Most of these intercepts are believed to be quartz veining originating in either the Upper or Footwall Subzone, that have been diverted from the sheared part of the zone, up to 15 m from the main bodies of mineralization. One of these zones is the Lynx Zone, which lies east of the southern end of the Sugar Zone.
The Middle Zone, located between the Sugar and Wolf Zones, may represent the extension of the Sugar Zone to the north. The zone occurs within a highly strained package of massive and pillowed flows exhibiting various degrees of biotite alteration. Gabbro sills and flows are common about the zone. Similar to the Sugar Zone, a weak Upper and Footwall Zone may locally be developed. The zone typically ranges from 1.5 to 10.0 m in thickness.
Middle Zone gold mineralization is often associated with quartz veins and veinlets hosted within a package of altered mafic volcanic and feldspar porphyry. The gold mineralization is often accompanied by 1-5% pyrrhotite and pyrite with local sections of minor galena and sphalerite. Galena is normally indicative of higher grades and the presence of visible gold.
The auriferous Wolf Zone lies along strike of the Sugar Zone, and may represent the northern extension of the SDZ. It is defined as highly strained packages consisting of variously altered mafic volcanic flows and gabbros. The zone ranges in true thickness from 0.5 to 8.0 m.
The Wolf Zone is made up of highly sheared mafic metavolcanics, and a network of intrusive, intermediate quartz-feldspar porphyry dykes/sills. Alteration in the mafic volcanic and gabbro units consists mainly of silicification (both pervasive and quartz veining), diopside alteration and magnesium rich, brown biotite alteration. Alteration within the intermediate porphyry units consist of mostly silicification, with small amounts of magnesium-rich brown biotite, and no diopside. The zone is observed in trenches to pinch and swell over 30 m.
Wolf Zone gold mineralization mostly occurs in quartz veins, stringers and quartz flooded zones predominantly associated with porphyry zones, and hydrothermally altered basalts and gabbros. Fine-grained specks of visible gold are occasionally observed in the Wolf Zone quartz veins. The visible gold itself is often observed to be concentrated within thin fractures, indicating some degree of remobilization. Quartz veins and floods also contain varying amounts of pyrrhotite, pyrite and occasional galena. The presence of galena is a strong indicator of the presence of visible gold. Pyrite and pyrrhotite form most of the total sulphides, but do not appear to be directly related to the presence of gold mineralization.
Deposit types
In the Superior Province, major gold deposits are spatially associated with large scale regional deformation zones and associated Timiskaming-type metasediments (LeClair et al. 1993). These regional structures are interpreted as zones of transpressive terrain accretion (Kerrich and Wyman 1990).
Typical greenstone-hosted, mesothermal gold deposits are associated with structurally controlled quartz-carbonate veins hosted by moderately to steeply dipping, shear zones displaying brittle to ductile deformational features in low grade (greenschist) metamorphic rocks. In contrast, the Sugar Zone Gold Deposit is hosted in medium-metamorphic grade (amphibolite) rocks that exhibit ductile deformation. The Sugar Zone host rocks have been intruded by felsite and porphyry sills and exhibit strong association of gold with silica-sulphide-potassic alteration. These characteristics are shared with the Hemlo Deposit located 68 km to the west.
The Sugar Zone is interpreted as an orogenic, mesothermal gold deposit located in the Sugar Deformation Zone, or SDZ, which is an area of high strain. The Sugar Zone, along with the Middle and Wolf Zone, are three known gold deposits on the SDZ within the Dayohessarah Greenstone Belt.
Additionally:
AIRBORNE EM/MAGNETIC SURVEY RESULTS AND PRIORITY TARGETS
DETAIL OF AIRBORNE MAGNETIC MAP IN SUGAR ZONE AREA SHOWING RELATIONSHIPS OF OTHER ZONES
STRUCTURAL TRENDS ON CONTOURED GRADE THICKNESS LONGITUDINAL PROJECTION
LONGITUDINAL BLOCK VIEW OF SUGAR ZONE AREA SHOWING RELATIONSHIP OF SUBZONES AND DRILL RESULTS
LONGITUDINAL PROJECTION – CONTOURED GOLD GRADES
Sugar zone resource and reserve
A source: TECHNICAL REPORT AND FEASIBILITY STUDY ON THE SUGAR ZONE GOLD OPERATION SAULT STE. MARIE MINING DIVISION, ONTARIO UTM ZONE 16U NAD83 646,140 m E, 5,406,900 m N FOR HARTE GOLD CORP. NI 43-101 & 43-101F1 TECHNICAL REPORT