Rubicon Minerals Provides an Update of its 2017 Exploration Program with Drill Results and Preliminary Observations

Structural drilling program – north-south (mine grid) oriented drilling at the 244-, 305-, and 610- metre levels with the objective of identifying and evaluating the geometry, thickness, and grade of the additional high-grade East-West trending quartz-breccia veins (not true widths, more details in the 'Qualified Persons and QA/QC' section below):

• 244-17-04: 115.19 grams per tonne of gold ("g/t Au") over 11.1 metres ("m") (including 758.70 g/t Au over 1.7 m)
• 244-17-07: 5.33 g/t Au over 7.1 m (including 14.17 g/t Au over 1.8 m)
• 305-17-01: 15.32 g/t Au over 2.3 m (including 23.40 g/t Au over 1.5 m)
• 305-17-06: 6.83 g/t Au over 12.6 m (including 29.70 g/t Au over 1.7 m)
• 305-17-09: 58.22 g/t Au over 7.4 m (including 199.66 g/t Au over 2.1 m)

Infill and step-out drilling program at the 305-, 610-, and 685-metre levels – with the objective of potentially upgrading and growing the 2016 Mineral Resources ("Mineral Resources")(not true widths, more details in the 'Qualified Persons and QA/QC' section below):

• 305-17-14: 8.09 g/t Au over 8.6 m (including 22.27 g/t Au over 2.9 m)
• 305-17-15: 8.54 g/t Au over 10.8 m (including 21.90 g/t Au over 1.5 m and 23.31 g/t Au over 1.9 m)
• 305-17-16: 6.72 g/t Au over 6.2 m (including 16.38 g/t Au over 1.8 m)
• 305-17-18: 6.13 g/t Au over 10.0 m (including 9.50 g/t Au over 3.7 m)
• 305-17-19: 7.78 g/t Au over 4.7 m
• 305-17-20: 21.52 g/t Au over 4.7 m (including 44.02 g/t Au over 1.5 m)
• 305-17-22: 9.78 g/t Au over 8.7 m (including 13.65 g/t Au over 5.9 m)
• 610-17-01: 6.70 g/t Au over 4.0 m (including 15.14 g/t Au over 1.7 m)
• 610-17-04: 9.75 g/t Au over 5.5 m (including 16.83 g/t Au over 3.0 m)
• 610-17-06: 12.89 g/t Au over 6.5 m (including 17.73 g/t Au over 4.6 m)
• 610-17-08: 5.21 g/t Au over 9.3 m (including 7.56 g/t Au over 4.1 m)

2017 Exploration Program Update

The Company completed its planned 3,500 m of structural oriented core drilling, 10,000 m of historical core re-logging and underground mapping activities, as part of its 2017 Exploration Program at the Phoenix Gold Project. The Rubicon team, together with Golder Associates Inc. ("Golder") and T. Maunula & Associates Consulting Inc. ("Maunula Associates"), is continuing to evaluate the data with the objective of updating the geological model for the F2 Gold Deposit, including the structural analysis.

Rubicon plans to continue its infill and step-out drilling at the 305-, 610- and 685-metre levels. Drilling will target the main zone of the F2 Gold Deposit with the objectives of increasing the drill density between the 366- and 854-metre levels, potentially grow the Mineral Resources and improve its classification. The Company will continue to collect structural data from its infill and step-out drilling throughout the mineralized zones and to supplement the structural data previously collected from the 3,500 m of structural oriented core drilling program, 10,000 m of historical core re-logging and mapping programs. As of September 14, 2017, the Company has completed 14,547 m of infill and step-out drilling of a planned 20,000 m.

Rubicon has also started exploratory underground development planning for the F2 Gold Deposit, with the goal to begin development before the end of 2017 and to potentially commence trial mining in 2018. Table 1 below provides a summary of the progress of the exploration activities undertaken to date.

Table 1: Exploration activities undertaken as of September 14, 2017:

Golder has provided oversight of the structural and definition drilling and the underground mapping programs, and has begun to successfully re-interpret the geological model (2016). The observed mapping, drilling and structural data collected has identified certain discrepancies with the previous lithological, mineralization, and structural interpretations. Work is ongoing to improve the representative geological model but it is uncertain at this time what impact the re-interpretation will have on the Mineral Resource Estimate. In addition, Maunula Associates will continue to act as a third-party independent consultant who will conduct a peer review at key milestones throughout the exploration program.

Golder has completed numerous Qualified Person (QP) site visits at the Phoenix Gold Project and has concluded that the geological and analytical procedures put in place by Rubicon for the 2017 Exploration Program are consistent with standard industry practises and that the data is of sufficient quality to support the ongoing Mineral Resource modelling.

Rubicon remains on schedule to deliver an NI 43-101 Technical Report and updated Mineral Resource Estimate in the second half of 2018. The Company has a cash balance of approximately C$28 million and remains on budget with its exploration program and corporate expenses.

Structural Geology – Analysis is Ongoing

Throughout its 10,000 m of historical core re-logging, 3,500 m of structural drilling from the 244- and 305-metre levels, and underground mapping activities, the Company has collected detailed structural data at the F2 Gold Deposit that was not previously captured. Many of the 10,000 m of historical re-logged drill holes were drilled in an east-west orientation (mine grid), resulting in sub-optimal orientations for evaluating the east-west oriented high-grade mineralization trends observed in the underground development and bulk sample analytical results. Subsequently, many of the 2017 structural drilling program drill holes were oriented north-south (mine grid) to allow for a better evaluation of the geometry and characteristics of the east-west mineralization trends. Rubicon and its consultants are currently analyzing the structural data to determine the relationship between the structures, the lithology, and the gold mineralization at the deposit.

Summary Assay Results and Diagrams

At the end of the news release, readers will find the following:

• Table 2: Summary of Drilling Assay Results, up to September 14, 2017.
• Diagrams 1 to 9: Structural drilling at the 244- and 305-metre levels, plan and section views.
• Diagrams 10 through 21: Infill and step-out drilling at the 305- and 610-metre levels, plan and section views.

Preliminary Observations up to September 14, 2017

The Rubicon team and its consultants have produced preliminary observations from the 2017 Exploration Program. Readers are cautioned that these observations could change as the Company advances its exploration activities. Rubicon believes there is inadequate information at this time to provide interpretations on an updated geological model and to update the Mineral Resources for the F2 Gold Deposit. The following are some initial observations:

• Gold intercepts encountered outside and within the 2016 Mineral Resource block model: Most of the mineralized gold intercepts encountered from the Company's structural, infill and step-out drilling programs to-date were within the 2016 Mineral Resource block model. In some instances, the Company encountered gold mineralization outside of the 2016 Mineral Resource block model. In addition, Rubicon encountered drill hole composite grades that are higher than the 2016 Mineral Resource block model. Examples of both these occurrences appear in Diagrams 3, 5 to 9, 11 to 14, 16, 17, 19 and 21.
• No significant mineralization was encountered in some areas where gold mineralization was anticipated: In some areas, the Company observed no significant mineralization where the 2016 Mineral Resource block model predicted gold mineralization. Examples of these appear in Diagrams 2, 5, 7, 11, 16, and 21.
• Flat-angled drilling from the 610-metre level getting proper horizontal widths: Historically, the drilling that reached the 610-metre level and below were steep-angle drill holes from surface. For the first time, the Company is able to drill flat-angled holes from the developed 610- and 685-metre levels, which allows Rubicon to test the true horizontal width of the gold mineralization. Diagrams 15 to 21 provide examples of horizontal drilling at the 610-metre level.
• Simplification of lithological descriptors: On the advice of its consultants, the logging procedures have been updated to allow the Company to simplify descriptors of lithological units compared to previous logging efforts. For example, Rubicon has logged the high-titanium basaltic metavolcanics units ("HiTi basalts"), the main host-rock of gold mineralization in the F2 Gold Deposit, into one singular unit compared to previously having multiple HiTi basalt descriptors.
• Multiple quartz breccia zones; different orientation: During the underground mapping exercise, the Company has observed multiple quartz breccia zones that were either non-existent or not adequately captured in the existing geological model (2016) for the deposit. Previously, Rubicon was aware of one main quartz breccia zone located near the 305-metre level, which hosted high-grade mineralization based on drilling and bulk sample testing. In addition, the orientation of the main quartz breccia zone is different compared to the previous understanding of this zone.
• East-west (mine grid) oriented mineralization not adequately modeled: Rubicon has observed a significant component of east-west oriented mineralization that is not adequately captured in the existing geological model (2016) for the deposit. Currently, the high-grade and low-grade mineralization shells are all oriented north-south (mine grid). The Company is improving its understanding of the east-west oriented mineralization.
• Structural mapping and logging of historical and new oriented core has provided meaningful data: The current structural mapping and historical core re-logging has allowed the Company to 1) locate and identify the mineralized system to help observe changes in mineralization styles; 2) observe quartz stringers that are carrying gold mineralization; 3) identify angles of structures and their impact on gold mineralization; and 4) add quantitative details on generations, frequency, orientation, aperture, and composition.

The Company intends to provide periodic updates as it completes the various elements and analysis of the exploration program.

CEO's Comments

"I am very pleased with the rapid advancement of the Phoenix Gold Project towards a geological re-interpretation and a new Mineral Resource Estimate," said George Ogilvie, P.Eng., President and Chief Executive Officer of Rubicon. "Completion of the 3,500 m of structural drilling, combined with re-logging of 10,000 m of historical core and underground mapping, provides an abundance of data to aid Golder in their re-interpretation of the geological model. I look forward to the completion of our 20,000 m of infill and step-out drilling and potentially continuing to encounter high-grade gold intersections, as well as the start of underground exploratory development before year-end."

"Although it is still early in the process of updating the geological model and the Mineral Resources, our initial observations are providing us with new insights into the F2 Gold Deposit," stated Mr. Ogilvie. "Most importantly, we have observed discrepancies between the existing geological model (2016) and the data collected from our exploration activities. In some instances, we encountered new gold mineralization outside and at higher grades compared to the 2016 Mineral Resource block model, while on the other hand, we are seeing some lower-grade or no significant mineralization in areas where the block model had predicted gold mineralization. In addition, the underground drilling from the 610- and 685-metre levels has allowed us to drill the deposit with better-angled holes in relation to the mineralized zone that provide a more representative true width. In time, this should help improve confidence in the geological and Mineral Resource modelling. We will endeavour to update the markets once we are able to provide a more comprehensive interpretation and understanding of the results."

Qualified Persons and QA/QC

The content of this news release has been read and approved by George Ogilvie, P.Eng., President and CEO, and Mark Ross, B.Sc., P.Geo., Chief Mine Geologist, for Rubicon. Both are Qualified Persons as defined by NI 43-101.

Underground drilling was conducted by Boart Longyear Drilling of Haileybury, Ontario and was supervised by the Rubicon exploration team. All assays reported are uncut unless otherwise stated. All samples reported herein were performed by SGS Mineral Services of Red Lake, Ontario.  All NQ core assays reported were obtained by fire assay with AA-finish or using gravimetric finish for values over 10.0 g/t Au.

Intercepts cited do not necessarily represent true widths, unless otherwise noted, however drilling is generally intersecting interpreted mineralized zones at a high angle. True width determinations are estimated at 65-80% of the core length intervals for the 244- and 305-metre level drilling, and estimated at 75-95% of the core length for the 610-metre level drilling.  Rubicon's quality control checks include insertion of blanks, standards and duplicates to ensure laboratory accuracy and precision.

About Rubicon Minerals Corporation
Rubicon Minerals Corporation is an advanced exploration company that owns the Phoenix Gold Project, located in the prolific Red Lake gold district in northwestern Ontario, Canada. Additionally, Rubicon controls over 280 square kilometres of prime exploration ground in Red Lake and more than 900 square kilometres of mineral property interests in the emerging Long Canyon gold district that straddles the Nevada-Utah border in the United States. Rubicon's shares are listed on the Toronto Stock Exchange (RMX) and the OTC markets (RBYCF). For more information, please visit our website at www.rubiconminerals.com.  

RUBICON MINERALS CORPORATION
"George Ogilvie, P.Eng."
President and CEO

Table 2: Summary of Drilling Assay Results, up to September 14, 2017

Cautionary Statement regarding Forward-Looking Statements and other Cautionary Notes

This news release contains statements that constitute "forward-looking statements" and "forward looking information" (collectively, "forward-looking statements") within the meaning of applicable Canadian and United States securities legislation. Generally, these forward-looking statements can be identified by the use of forward-looking terminology such as "believes", "intends", "may", "will", "should", "plans", "anticipates", "potential", "expects", "estimates", "forecasts", "budget", "likely", "goal" and similar expressions or statements that certain actions, events or results may or may not be achieved or occur in the future. In some cases, forward-looking information may be stated in the present tense, such as in respect of current matters that may be continuing, or that may have a future impact or effect. Forward-looking statements reflect our current expectations and assumptions, and are subject to a number of known and unknown risks, uncertainties and other factors which may cause our actual results, performance or achievements to be materially different from any anticipated future results, performance or achievements expressed or implied by the forward-looking statements. Forward-looking statements include, but are not limited to statements regarding the details of the planned exploration of the F2 Gold Deposit, the objectives of the Company's drilling programs, the expected timing of potential exploratory underground development and potential test trial mining and the preliminary observations from the Company's 2017 Exploration Program.

Forward-looking statements are based on the opinions and estimates of management as of the date such statements are made and represent management's best judgment based on facts and assumptions that management considers reasonable. If such opinions and estimates prove to be incorrect, actual and future results may be materially different than expressed in the forward-looking statements.

Forward-looking statements involve known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of Rubicon to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. Such factors include, among others: possible variations in mineralization, grade or recovery or throughput rates; uncertainty of mineral resources, inability to realize exploration potential, mineral grades and mineral recovery estimates; actual results of current exploration activities; actual results of reclamation activities; uncertainty of future operations, delays in completion of exploration plans for any reason including insufficient capital, delays in permitting, and labour issues; conclusions of future economic or geological evaluations; changes in project parameters as plans continue to be refined; failure of equipment or processes to operate as anticipated; accidents and other risks of the mining industry; delays and other risks related to operations; timing and receipt of regulatory approvals; the ability of Rubicon and other relevant parties to satisfy regulatory requirements; the ability of Rubicon to comply with its obligations under material agreements including financing agreements; the availability of financing for proposed programs and working capital requirements on reasonable terms; the ability of third-party service providers to deliver services on reasonable terms and in a timely manner; risks associated with the ability to retain key executives and key operating personnel; cost of environmental expenditures and potential environmental liabilities; dissatisfaction or disputes with local communities or First Nations or Aboriginal Communities; failure of plant, equipment or processes to operate as anticipated; market conditions and general business, economic, competitive, political and social conditions; our ability to generate sufficient cash flow from operations or obtain adequate financing to fund our capital expenditures and working capital needs and meet our other obligations; the volatility of our stock price, and the ability of our common stock to remain listed and traded on the TSX.

Forward-looking statements contained herein are made as of the date of this news release and Rubicon disclaims any obligation to update any forward-looking statements, whether as a result of new information, future events or results or otherwise, except as required by applicable securities laws. Readers are advised to carefully review and consider the risk factors identified in the Company's annual information form dated March 29, 2017 under the heading "Risk Factors" and in other continuous disclosure documents of the Company filed at www.sedar.com for a discussion of the factors that could cause Rubicon's actual results, performance and achievements to be materially different from any anticipated future results, performance or achievements expressed or implied by the forward-looking statements. Readers are further cautioned that the foregoing list of assumptions and risk factors is not exhaustive and it is recommended that prospective investors consult the more complete discussion of Rubicon's business, financial condition and prospects that is included in this news release. The forward-looking statements contained herein are expressly qualified by this cautionary statement.

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

SOURCE Rubicon Minerals Corporation

Related Links

www.rubiconminerals.com