Eastmain and Partners Announce Drilling Results from the Fall 2018 Exploration Program at Éléonore South Joint Venture

TORONTO, Dec. 17, 2018 - Eastmain Resources Inc. (“Eastmain” or the “Company”- TSX:ER, OTCQX:EANRF) announces drill assay results from 14 holes (4,285 m) in the Fall 2018 Exploration Program at the Éléonore South Joint Venture Property (“ESJV”) located in James Bay, Quebec (see FIGURE 1). Results are pending on 10 additional drill holes (approximately 3,000 m).

Early drilling focused in the eastern section of the Contact Trend at Éléonore South, and successfully identified and extended the known gold mineralization (see FIGURES 2 and 3). Several intercepts also identified high-grade gold mineralization in relation to lamprophyre dykes within the system. Drilling also intersected mineralization northwards from the Contact Trend into a more central portion of the Cheechoo tonalite, within the large gold bearing system which extends at least 2 km long, and 600-700 m wide.

Drilling Highlights:

• ES18-133: 14.7 g/t Au over 6.2 m (vertical depth 129 m), incl. 80.4 g/t Au over 1.0 m (visible gold)
• ES18-126: 2.08 g/t Au over 8.0 m (vertical depth 111 m), incl. 3.52 g/t Au over 4.5 m, also incl. 8.22 g/t Au over 1.5 m
• ES18-121A: 1.85 g/t Au over 8.7 m (vertical depth 47 m), incl. 3.83 g/t Au over 3.9 m (visible gold)

Claude Lemasson, Eastmain President & CEO, stated: “We are pleased with the progress made to date at the Moni/Contact Trend discovery. Since 2016, a total of 90 drill holes have identified significant shallow tonalite-hosted gold mineralization within this large gold-bearing system. These latest results indicate the extension of the system as predicted, with the potential to extend an additional 3 km to the JT Prospect along the semi-circular trend to the west.”

Continuation of the Fall 2018 Drill Program

The balance of the Fall 2018 Drill Program comprises an additional 3,000 m of drilling for a total of 7,000 m completed by year end, targeting the western edge of the Contact Trend at the JT Prospect and testing structural interpretations in the Moni Trend. An additional hole has recently been completed to the SW of hole ES18-133 to test for an extension of the high-grade gold interval (14.7 g/t Au over 6.2 m) associated with a lamprophyre dyke intercepted in this hole. Future exploration will include exploring the relation of gold mineralization to the lamprophyre dykes within the system.

Highlights from completed holes are presented in Table 1 below. A more detailed summary of significant intercepts and drill locations can be found in TABLE 2 and Table 3.

Table 1: Drill Assay Highlights ^{(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. VG Visible Gold.

Contact Trend Target Observations from Current Drilling Results

Drill holes ES18-120 to ES18-124 tested extensions to gold mineralized intersections obtained from a cluster of drill holes including ES17-74 (0.56 g/t Au over 54.5 m from 190.5 m to 244.5 m) (see FIGURE 4). All drilling targeted the Contact Trend gold mineralization that is hosted in the Cheechoo tonalite. Highlights include:

• Hole ES18-121a was collared 100 m SW of hole ES17-74 and intersected several intervals near surface starting at; 57.3 m (1.85 g/t Au over 8.7 m); 78.6 m (3.83 g/t Au over 3.9 m); and at 90.0 m (2.84 g/t Au over 3.9 m) but did not replicate the deeper interval seen in ES17-74.
• Hole ES18-122 tested 100 m SE along section of Hole ES18-111 (1.4 g/t Au over 9.4 m from 267.3 m to 276.6 m) and returned numerous mineralized intervals, including 0.81 g/t Au over 25.15 m from 57.9 m to 83.0 m.
• Hole ES18-123 tested for Contact Trend type mineralization 85 m SE along section from hole ES17-78 (0.51 g/t Au over 17.1 m from 212.5 m to 229.5 m) and returned several anomalous intervals including 0.47 g/t Au over 59.0 m from 119.0 m to 178.0 m.

Hole ES18-125 to ES18-129 were drilled along a NE trend testing out 100 m to the SW and 200 m to the NE along the Contact Trend, from the center of a cluster of previous drill holes around ES17-80 and ES17-88 (see FIGURE 5). Highlights include:

• Hole ES18-126 was drilled 50 m NE of hole ES18-112 (0.70 g/t Au over 43.4 m from 108.2 m to 151.6 m), returning two notable intervals of 2.08 g/t Au over 8.0 m from 141.0 m to 149.0 m and 0.51 g/t Au over 10.5 m from 167.5 m to 178.0 m.
• Hole ES18-129 was drilled 50 m SW of hole ES17-90 (0.5 g/t Au over 123.5 m from 92.0 m to 215.5 m). This hole did not return a large low-grade intersection but did intersect several gold intervals including; 0.50 g/t Au over 6.4 m from 94.5 m to 100.9 m, 0.79 g/t Au over 5.5 m from 129.0 m to 134.5 m, 1.51 g/t Au over 10.0 m from 143.5 m to 153.5 m (incl. 12.7 g/t Au over 1.0 m), and 2.09 g/t Au over 7.5 m from 173.0 m to 180.5 m (incl. 8.02 g/t Au over 1.5 m).

Holes ES18-130 to ES18-133 are drilled as a fence section in an open area located 100 m to 150 m SW of the cluster of drill holes around ES17-80 and ES17-88 (see FIGURE 6). Highlights include:

• Hole ES18-133 intersected 2.82 g/t Au over 3.0 m from 103.0 m to 106.0 m and 14.7 g/t Au over 6.2 m from 164.8 m to 171.0 m, including 80.4 g/t Au over 1.0 m. This intersection contains visible gold in tonalite but is closely spatially related to an actinolite schist, interpreted as an altered and sheared lamprophyre dyke. A similar interval is cut by hole ES16-57 located 80 m to the NE of hole ES18-133. This intercept assayed 76.1 g/t Au over 1.55 m in tonalite, spatially related in similar fashion to an adjacent lamprophyre dyke.
• Hole ES18-132 intersected 2.22 g/t Au over 5.1 m from 43.9 m to 49 m including 0.8 m 13.0 g/t Au.

For more detail on previous drill results up to ES18-119, please refer to press releases dated Nov. 3, 2016, Nov. 21, 2016, May 2, 2017, May 30, 2017, Nov. 16, 2017, Dec. 12, 2017 and July 18, 2018.

Exploration Potential in the Cheechoo Tonalite

The Joint Venture began exploring the Cheechoo tonalite intrusion in 2016. A total of 76 diamond drill holes totaling 15,134 m) were completed on the property up to the beginning of the Fall 2018 drill program and have successfully identified a large gold-bearing system within the margin of the Cheechoo tonalite intrusion located in the eastern section of the ESJV property. Drilling has identified gold mineralization in a 600-700 m wide zone extending over two kilometres along a north-easterly trend. The mineralization extends towards the Sirios Cheechoo discovery to the northeast and is open to the west and southwest. The gold-bearing system being targeted is wholly contained within the Cheechoo tonalite intrusion and comprised of two main expressions:

• The Contact Trend: A mineralized and altered envelope of variable thickness in tonalite which ranges from several tens of metres to over 100 m in core length with continuous intervals of anomalous gold values. Within these intervals are sections ranging to several tens of metres returning above 0.5 g/t Au. Alteration is characterized by the appearance of one or several networks of quartz veins and veinlets, sodic alteration (albite), the presence of frequent visible gold grains and a notable but very low sulphide concentration (<0.5%) including arsenopyrite. Drilling has also identified evidence of folding and shear deformation within the intrusive as well as the local injection and subsequent alteration and deformation of mafic dykes believed to be lamprophyres; and,
• The Moni Trend: Several high-grade gold mineralized zones characterized by a) clusters of quartz-albite-biotite stockwork accompanied by arsenopyrite, pyrrhotite, pyrite, scheelite and visible gold, and b) pegmatitic veins of coarse quartz and feldspar or veins of coarse-grained quartz with lesser amounts of interstitial feldspar having well distributed visible gold and very low sulphide content.

The late (2.61 billion-year-old) Cheechoo tonalite is interpreted to be a mushroom shaped intrusion, based on two observed components: a) a thick planar body with a south and southwest dipping roughly tabular, 450 m to 500 m thick, top as determined by the 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): and b), a root zone corresponding to a magnetically quiet core area located to the ENE of JT Prospect. The current interpretation suggests the intrusion has not been overturned. Evidence from surface mapping and core examination indicate significant deformation (folding) may occur in the tonalite. The Contact Trend is interpreted to represent a decompression stockwork zone close to the top of the intrusion. This mineralized zone may extend down dip along the top of the intrusion, parallel to, and below, the contact with the overlying metasedimentary country rocks. The relationship of the high-grade Moni-type veins to Contact Trend mineralization is not fully established yet. They are explored separately but certain elements of the alteration and mineralization such as distribution of visible gold and generally low sulphide contents suggest common genesis. Further discussion of the exploration model adopted for the Cheechoo tonalite mineralization is provided in a press release dated July 18, 2018.

The JT Prospect is located 2.5 km to 3 km to the west of the Contact and Moni Trends. This is a gold-bearing zone explored by drilling in 2008-2010 while targeting sedimentary sequences believed to have a similar geology to those within the stratigraphy hosting the Éléonore gold mine, located 12 km to the northwest. Gold was identified in the metasedimentary rocks located above the tonalite-metasedimentary contact at the time. Tonalite was generally used to define the base of drilling, however analytical results from some historic drill holes indicate that the Cheechoo tonalite is also mineralized in this area, including hole ES08-12 which returned 2.15 g/t Au over 14.0 m in the intrusive (see FIGURE 3).

Gold intercepts in tonalite at the JT Prospect near the intrusive-metasedimentary contact may extend the highly prospective Contact Trend to a semi-circular ring shape of approximately 5.5 km in length. The Joint Venture conducted an initial drill test with 4 holes in the Cheechoo tonalite below the JT Prospect during this program, results are pending.

To view Figures 1 - 6, please click on the following link: http://www.eastmain.com/_resources/news/Images/ER-181217-figures1-6.pdf
To view Table 2, please click on the following link: http://www.eastmain.com/_resources/news/Images/ER-181217-ESJVtable2.pdf

Table 3: 2018 Drill Hole Location Information

About the Éléonore 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%). Eastmain is the operator of the current program under the supervision of William McGuinty, P. Geo., Eastmain’s VP Exploration, a qualified person as defined by National Instrument 43-101. This press release and supporting technical information was reviewed by William McGuinty.

About Eastmain Resources Inc. (TSX:ER, OTCQX:EANRF) www.eastmain.com
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 Clearwater Property, host of the Eau Claire Project, for which it issued a Preliminary Economic Assessment (“PEA”) in May 2018, and the Percival Discovery made in November 2018. Eastmain is also the operator of the Éléonore South Joint Venture, located immediately south of Goldcorp Inc.'s Éléonore Mine, which hosts the Moni/Contact Trend Discovery (2017). In addition, the Company has a 100% interest in the Eastmain Mine Project where the Company prepared a NI 43-101 Mineral Resource Estimate in January 2018, and 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

Alison Dwoskin, Investor Relations
+1 647-347-3735
dwoskin@eastmain.com

Quality Control and Assurance - The design of the Eastmain Resources’ drilling programs, Quality Assurance/Quality Control and interpretation of results is under the control of Eastmain’s geological staff, including qualified persons employing a strict QA/QC program consistent with NI 43-101 and industry best practices. The Éléonore South Joint Venture Project is supervised by Eastmain’s Project Geologist, Daniel Turgeon, P. Geo.

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.