Winter Drilling Strengthens Model for Large-Scale Intrusive Hosted Gold System at Éléonore South

TORONTO, July 18, 2018 -- Eastmain Resources Inc. (“Eastmain” or the “Company”) (TSX:ER) (OTCQX:EARNF) is pleased to announce the receipt of assay results from 32 drill holes totalling 5,449 m completed during the winter drilling campaign at the Éléonore South Joint Venture (ESJV) Property (Eastmain-Goldcorp-Azimut). This phase completes the H2/2017-H1/2018 diamond drilling program of 50 holes for a total of 9,892 m. Located in the James Bay region of Quebec, Eleonore South is adjacent to the property that hosts the Éléonore gold mine owned and operated by Goldcorp (see Figure 1).

Surface exploration and diamond drilling on the Éléonore South property since 2016 (76 holes totalling 15,134 m) have uncovered a large gold-bearing system extending least 2 km in length and 600 to 700 m in width, within a tonalite intrusion in close proximity to the contact with overlying metasedimentary rocks containing:

• A mineralized envelope with consistently anomalous gold values ranging from 50 ppb to 900 ppb with multi-metre intervals ranging to 0.5 g/t Au characterized by the appearance of one or several networks of quartz veins and veinlets, strong sodic alteration, very low sulphide concentrations (<0.5%) and frequent visible gold grains (“Contact Trend”);
  
  
• Several high-grade zones characterized by; a) clusters of quartz-albite-biotite stockworks accompanied by arsenopyrite, pyrrhotite, pyrite, scheelite and visible gold, and b) quartz-feldspar pegmatitic vein systems with visible gold (“Moni Trend”).

The JT Prospect is a sediment-hosted gold-bearing zone discovered in 2006 situated in stratigraphy at the contact with the tonalite intrusion, 2.5 km to the west of current exploration. Results from 2008 drilling indicate that the tonalite is also mineralized in this area. The JT Prospect and related stratigraphy near the tonalite contact extends the highly prospective zone to a semi-circular shape of approximately 5.5 km in length with considerable upside exploration potential.

Table 1 below reports highlights of the winter drilling campaign. Table 2 provides additional assay results. Table 3 provides drill hole location data. See Figure 2 and Figure 3 for location of drill holes.

Table 1: Highlights from 2018 Drilling Results^(1),(2),(3)

Notes: (1) Intervals are presented in core length; true width will vary depending on the intersection angle of the hole with the targeted zone, (2) Assays presented are not capped. (3) Vertical depth is measured from the surface to the mid-point of the reported interval.

Technical Comments

The Moni Trend has been drilled with 20 holes totalling 2,351 m, including 12 holes totalling 754.8 m at the Moni Prospect. This includes the extension of hole ES16-48 by 107 m (final depth of hole ES18-48ext; 258 m) and one abandoned hole (ES18-92 at 14.6 m). The northeast-striking Moni Trend is hosted in the tonalite intrusion, about 500 m from the metasedimentary contact.

The results of the closely spaced holes on the Moni Prospect (see Figures 5 and 6) indicate good geometric continuity for the northeast-striking quartz-feldspar pegmatitic vein system to a tested depth of 40 m below surface and along a 60 m strike length. The best results include 42.4 g/t Au over 7.0 m (hole ES18-100), 8.56 g/t Au over 8.4 m (hole ES18-98) and 13.6 g/t Au over 2.5 m (hole ES18-95). These drill results correlate well with channel sampling results obtained above these intersections returning up to 79.5 g/t Au over 5.87 m and 79.6 g/t Au over 4.25 m (see press release of October 17, 2017). Variable and locally very high gold values intersected in these veins are related to the presence of visible gold whose distribution within the vein and vein intercepts can vary greatly. Several holes testing the Moni Prospect also intersect a brittle post-mineralization fault causing strong fragmentation and local core loss within some of the gold-bearing pegmatitic veins.

Despite the grade variability attributed to distribution of visible gold, the 60 m by 40 m dense drilling test below known surface mineralization was a useful tool for establishing the potential for continuity of gold mineralization in a Moni Type vein system. The results increase the confidence for successful drilling of similar veins. Future surface work, including trenching, along the Moni Trend will be undertaken to identify new vein exposures where targeted ‘postage stamp’ drill grids can test for continuity. Such tests will improve the understanding of the structure and dimension of these high-grade veins and assist with drill program design to quantify Moni Type veins at the scale of the tonalite intrusion.

Drilling along the Moni Trend returned encouraging values that may indicate multiple subparallel high-grade veins within a 200 m wide corridor to the southwest from the Moni Prospect including;

• 6.05 g/t Au over 3.5 m (hole ES18-101)
• 15.7 g/t Au over 0.55 m (hole ES18-102)
• 10.4 g/t Au over 1.5 m (hole ES18-119)

The Moni-type vein systems at the Moni Prospect and within the currently defined Moni Trend remain open at depth and laterally and warrant additional drilling.

The Contact Trend was drilled with 12 holes totalling 3,097 m during the winter program. This includes the extension of hole ES16-51 by 117 m (final depth of ES18-48ext, 366 m) and one abandoned hole (ES18-108 at 57.0 m). Drilling confirms the presence of consistent gold mineralization along a zone at least 1.2 km long and 150 to 300 m wide, adjacent to the tonalite - metasedimentary contact. The recent drilling further corroborates geometric continuity of gold mineralization identified within three drill hole clusters in 2017. These zones remain and open down dip and along strike. From northeast to southwest, the clusters yielded the following results:

• Hole ES18-108a (see Figure 7) returned 1.12 g/t Au over 33.6 m and 0.69 g/t Au over 84.8 m, incl. 1.17 g/t Au over 10.9 m and 1.23 g/t Au over 16.1 m. Hole ES18-108a represents the downdip extension of the previously reported results from hole ES17-77 (1.46 g/t Au over 45.5 m, 0.53 g/t Au over 106.0 m and hole ES17-60 (0.65 g/t Au over 144.0 m incl. 1.9 g/t Au over 22.5 m, 4.74 g/t over 6.0 m.

This cluster is northeast trending, 200 m long by 100 m wide with a 50^o to 60^o dip to the southeast.

• Hole ES18-111 (see Figure 8) returned 1.41 g/t Au over 9.4 m incl. 5.64 g/t Au over 1.0 m and 2.18 g/t Au over 5.6 m; and Hole ES18-51ext returned 0.57 g/t Au over 143.1 m incl. 5.0 g/t Au over 4.0 m, 14.1 g/t Au over 1.0 m, 0.81 g/t Au over 28.5 m and 1.16 g/t Au over 6.7 m. Both holes represent the extension of following previously reported significant results:
  • 3.06 g/t Au over 77.3 m incl. 4.9 g/t Au over 45.0 m (hole ES17-64)
  • 1.58 g/t Au over 12.0 m and 0.59 g/t Au over 28.5 m (hole ES16-55)
  • 0.45 g/t Au over 87.0 m (hole ES17-74)

This cluster measures at least 300 m long by 50 m wide and is northeast trending with a possible subhorizontal to shallow dip to the southeast.

• Hole ES18-113 returned 2.18 g/t Au over 3.0 m, 1.13 g/t Au over 9.9 m and 0.62 g/t Au over 16.0 m. This hole represents the extension of the following previously reported significant results:
  • 0.49 g/t Au over 76.5 m (hole ES17-87)
  • 0.62 g/t Au over 147.5 m incl., 5.76 g/t Au over 9.0 m (hole ES17-80)
  • 1.53 g/t Au over 6.0 m and 3.15 g/t Au over 24.0 m (hole ES17-88)
  • 0.50 g/t Au over 123.5 m incl. 4.45 g/t Au over 4.5 m, 12.4 g/t Au over 1.5 m and 1.04 g/t Au over 6.0 m (hole ES17-90).

This cluster has a minimum northeast trending extent of 300 long by 100 m wide with a possible subhorizontal orientation.

Drilling also investigated an untested area between two clusters centred on holes ES18-111 and ES18-113 respectively. Three holes drilled within a 500 m interval returned the following highlights; 0.71 g/t Au over 43.4 m including 10.2 g/t Au over 1.0 m (hole ES18-112) and 0.48 g/t Au over 15.4 m (hole ES18-117.

Exploration Model and Upside

• Several key factors point toward an intrusion-related deposit type for the gold-bearing system identified at Eleonore South (see press release of February 27, 2018). The Fort Knox mine in Alaska (Kinross Gold Corp.) and the Côté Lake Project in Ontario (IAMGOLD) are examples of large-scale intrusion-related gold deposits.
  
  
• In this scenario, assessing the geometry of the intrusion and the surrounding metasedimentary rocks is critical given that the tops of intrusions are typically viewed as highly prospective.
  
  
• Subject to further validation, the tonalite intrusion appears to be a thick planar body (450 m to 500 m thick) with a moderate to shallow dip to the south or southeast along its southern boundary, and a dip to the west along its western boundary (JT Prospect area).
  
  
• Decompression along the upper contact of the tonalite intrusion may have been the main control for mineralization along the Contact Trend, with decompression related fracturing acting as a conduit and trap for late-stage magmatic-hydrothermal fluids. Main features in this zone include networks of veins and veinlets, stockworks, and quartz-feldspar pegmatites, all of which are associated with large alteration zones (200 m to 400 m thick).
  
  
• The Moni Trend mineralization may also be related to decompression of the tonalite intrusion although its high-grade veinlets do not appear to be hosted within a broad altered and gold-mineralized halo and its steeply dipping orientation suggests additional, or locally different, structural control.
  
  
• Additional significant exploration upside exists within the portions of the tonalite located under the metasediments as shown by the results obtained in holes ES18-108a and ES18-113. The same configuration exists at the JT Prospect where historic hole ES08-12 returned 2.15 g/t Au over 14 m.
  
  
• The JT Prospect sediment-hosted gold-bearing mineralization located at the contact with, and overlying the tonalite intrusion also appear to be highly prospective and warrant further evaluation as the underlying tonalite is explored for Contact Trend mineralization.
  
  
• Together the mineralization related to the tonalite intrusion contact on the Éléonore South property describe a 5 km semi circular trend of which 2016-2018 exploration has tested less than 20% with close spaced (25 – 50m) drilling
  
  
• Future exploration at Eleonore South will focus on the two main intrusion-related target types identified at Eleonore South; the network of high-grade veins along the Moni Trend and; the wide, low-grade (0.5 g/t Au to 1.0 g/t Au) gold-bearing system along the Contact Trend.

Table 3: 2018 Drill Hole Location Information.

To view FIGURES 1–8, please click on the following link: http://www.eastmain.com/_resources/images/Figures_1-8.pdf

To view TABLE 2, please click on the following link: http://www.eastmain.com/_resources/images/Table_2.pdf

About the Eleonore South Joint Venture Property

The Éléonore South Property is being explored as a three-way Joint Venture between Eastmain Resources Inc. (36.7%), Azimut Exploration Inc. (TSX-V:AZM) (26.6%), and Goldcorp Inc. (TSX:G) (NYSE:GG) (36.7%). Azimut is the operator of the current program under the supervision of Dr. Jean-Marc Lulin and the field direction of François Bissonnette, both professional geologists and qualified persons under National Instrument 43-101. This press release and technical and information provided by Azimut was reviewed by William McGuinty, P. Geo., Eastmain’s VP Exploration and a Qualified Person under National Instrument 43-101.

Drill core samples were sent to ALS Minerals in Val-d'Or, Quebec. Gold was analyzed by fire assay with atomic absorption and gravimetric finish for grades above 3.0 g/t Au. Samples were also analyzed for a 48-element suite using ICP. Azimut applies industry-standard QA/QC procedures to the program. Certified reference materials, blanks and field duplicates were inserted in all drill core shipments to the laboratory.

About Eastmain Resources Inc. (TSX:ER, OTCQX:EANRF)

Eastmain is a Canadian exploration company advancing three high-grade gold assets in the emerging James Bay gold camp in Québec. The company holds a 100% interest in the Eau Claire Project, for which it recently issued a Preliminary Economic Assessment (“PEA”) and the Eastmain Mine Project where the Company has prepared NI 43-101 Mineral Resource Estimates in 2018. Eastmain is also a partner in the Éléonore South Joint Venture located immediately south of Goldcorp Inc.'s Éléonore Mine which hosts a new high-grade gold discovery found in late 2017. In addition, the company has a pipeline of exploration projects in this favourable mining jurisdiction with nearby infrastructure.

For more information:
Claude Lemasson, President and CEO
+1 647-347-3765
lemasson@eastmain.com

Laurenn Russell, Investor Relations Consultant
+1 647-347-3735
lrussell@eastmain.com

Forward-Looking Statements - Certain information set forth in this news release may contain forward-looking statements that involve substantial known and unknown risks and uncertainties. Forward-looking statements consist of statements that are not purely historical, including statements regarding beliefs, plans, expectations or timing of future plans, and include, but not limited to, statements with respect to the potential success of the Company’s future exploration and development strategies. These forward-looking statements are subject to numerous risks and uncertainties, certain of which are beyond the control of Eastmain, including, but not limited to the impact of general economic conditions, industry conditions, dependence upon regulatory approvals and the availability of financing, timely completion of proposed studies and technical reports, and risks associated with the exploration, development and mining industry generally such as economic factors as they effect exploration, future commodity prices, changes in interest rates, safety and security, political, social or economic developments, environmental risks, insurance risks, capital expenditures, operating or technical difficulties in connection with development activities, personnel relations, the speculative nature of gold exploration and development, including the risks of diminishing quantities of grades of Mineral Resources, contests over property title, and changes in project parameters as plans continue to be refined. Readers are cautioned that the assumptions, used in the preparations of such information, although considered reasonable at the time of preparation, may prove to be imprecise and, as such, undue reliance should not be placed on forward-looking statements. The Company assumes no obligation to update such information, except as may be required by law.