TORONTO, ONTARIO--(Marketwire - March 22, 2011) - Thundermin Resources Inc. ("Thundermin") (News - Market indicators) and 50% joint venture partner Cornerstone Resources Inc. ("Cornerstone") (TSX VENTURE:CGP) announce that they have intersected high grade copper mineralization assaying 4.1% Cu over 10.6 m, including 6.7% Cu over 5.8 m, and 4.5% Cu over 5.9 m within the Little Deer Copper Deposit ("Deposit") which is located approximately 10 km north of Springdale in north-central Newfoundland (see Table 1 and Figure 1).

A $1,600,000 diamond drilling program, comprising approximately 12,000 to 13,000 m of drilling in 18 to 20 holes and employing two drills, commenced on the Deposit on December 1, 2010. A total of 6,372 m of drilling in 13 holes has been completed to date. The primary purpose of this drill program is to increase the estimated mineral resources outlined to date in the Deposit to the five to six million tonne range. The potential increase of the current mineral resources is conceptual in nature and it is uncertain whether further exploration drilling will result in an expansion of this mineral resource.

The current drill program is focusing on three main areas: 1) above the -250 m elevation where the recent recovery of drill logs and assay data for 47 surface and 86 underground historical drill holes suggests that there is good potential for outlining additional high grade resources (see news release dated January 20, 2011); 2) along strike both east and west of the limits of the currently outlined mineral resource; and 3) at depth below the -650 m elevation where a preliminary interpretation of the results from borehole Pulse electromagnetic surveys suggest that there is potential for the discovery of additional copper mineralization.

The Deposit has been outlined by drilling over a strike length of 1,050 m and to a vertical depth of 1,000 m. Note that Figure 1 presented here shows only the upper eastern portion of the Deposit (see the longitudinal section accompanying the news release dated July 29, 2010 for a view of the complete Deposit). Additional details on the Deposit can be found in numerous Thundermin and Cornerstone news releases dated between May 1, 2007 and January 20, 2011 which are on each company's website and on SEDAR.

Holes LD-10-39, LD-10-40 (both previously reported) and LD-10-41 collectively totaling 966 m of drilling were completed in December prior to the seasonal shutdown (see Figure 1 and Table 1). These holes were drilled to confirm the presence of high grade copper mineralization believed to exist in the upper portion of the Deposit based on a review of the historical data referenced above. Hole LD-10-39, which intersected high grade massive, semi- massive and stringer chalcopyrite-pyrite-pyrrhotite mineralization was drilled to confirm the copper mineralization in historical surface hole LD-62-78 which intersected 2.9% Cu over 60.1 m, including intervals of 5.9% Cu over 7.9 m, 5.3% Cu over 15.5 m and 3.1% Cu over 11.6 m. Hole LD-10-40, which was drilled approximately 35 m west of LD-10-39, intersected minor copper mineralization comprising 2.4% Cu over 0.7 m. Hole LD-10-41 was drilled approximately 50 m east of hole LD-10-39 to confirm the copper mineralization in historical surface hole LD-62-83 which intersected 3.1% Cu over 13.7 m. Hole LD-10-41 intersected 2.1% Cu over 3.0 m and 4.5% Cu over 5.9 m. Three additional shallow holes are planned to the west in this area of the Deposit. These holes will be drilled on approximately 100 m centers to target the -100 m elevation (see Figure 1).

Hole LD-11-45, drilled on the upper western margin of the Deposit, intersected 1.4% Cu over a core length of 5.4 m and hole LD-11-48 intersected 1.4% Cu over 1.0 m. Holes LD-11-43 and LD-11-46, also on the upper western margin of the Deposit, intersected intervals of chlorite alteration with no significant copper mineralization. Hole LD-11-44, drilled on the upper eastern margin of the Deposit intersected high grade copper mineralization assaying 9.3% Cu over 1.6 m and 4.1% Cu over 10.6 m, including 6.7 % Cu over 5.8 m. Holes LD-11-42 and LD-11-47, also on the upper eastern margin of the Deposit, intersected thick sections of chlorite alteration with no significant copper mineralization. Holes LD-11-49, LD-11-50 and LD-11-51 have been completed. Assay results are awaited and will be reported when received.

Mineral Resource Estimate

On October 13, 2010, Thundermin and Cornerstone announced that an updated NI 43-101 compliant mineral resource estimate had been completed by Scott Wilson RPA under the supervision of Mr. Reno Pressacco, M.Sc. (A), P.Geo., Senior Geologist for Scott Wilson RPA and an independent Q.P. in accordance with NI 43-101. Scott Wilson RPA estimated that the Deposit contains Indicated Resources of 1,150,500 t at an average grade of 2.8% Cu within the Little Deer Zone and additional Inferred Resources of 1,227,300 t at an average grade of 2.2% Cu within the Little Deer Zone and 1,108,200 t at an average grade of 1.9% Cu within the Footwall Zone. A NI 43-101 compliant Letter Report entitled "Mineral Resource Update for the Little Deer Project" dated September 30, 2010, to support the updated mineral resource estimate, is available on Thundermin's and Cornerstone's websites.

Metallurgy

On October 19, 2010, excellent metallurgical results from scoping level test work on core samples from the Deposit were announced. This work, which was undertaken at SGS Lakefield Research Limited ("Lakefield") of Lakefield, Ontario, indicates that a saleable, high grade copper concentrate grading over 28% copper with over 97% recovery and free of any deleterious elements can be produced from the Deposit.

Qualified Person

Mr. Andrew Hussey, P.Geo., Project Geologist and Lands Manager, Cornerstone Resources Inc., is the Q.P. responsible for supervising the drilling program and the compilation of all of the historical data on the Deposit for the purposes of NI 43-101. Mr. Hussey has also reviewed the contents of this news release for accuracy. All holes drilled by Thundermin and Cornerstone are NQ in size. Specific gravity measurements, rock quality designations and photographic logging of significant mineralized intersections are performed systematically prior to assaying. The core is logged and the mineralized sections, where appropriate, are sawn in half at a core logging facility in Springdale. Half of the core is submitted for analyses to Eastern Analytical Limited, an independent and qualified assayer located in Springdale, and the remaining half of the core is kept for future reference. Blanks, duplicates and standards are routinely used as part of the assay procedures.

Little Deer Joint Venture

Thundermin, the operator, and Cornerstone have the option, on a 50/50 basis to earn a 100% interest in the Little Deer Copper Deposit and adjacent property from Weyburn Investments Ltd. Thundermin, under its joint venture agreement with Cornerstone, has the right to increase its interest in the Little Deer property to 75% by completing a feasibility study and by arranging 100% of the necessary bank financing required to place the property into commercial production. Details on the Deposit and the terms of the agreement with Weyburn can be found in numerous news releases and on Thundermin's and Cornerstone's respective websites and on SEDAR.

Junior Exploration Assistance Program

Thundermin and Cornerstone would like to acknowledge the financial support received from the Junior Exploration Assistance (JEA) Program of the Province of Newfoundland and Labrador in carrying out a portion of their work on the Little Deer property.

About Thundermin

Thundermin is a Canadian-based mineral exploration company focused on the exploration for and the discovery of economically viable base metal and gold deposits in Canada. Thundermin has an interest in, or the right to earn an interest in 11 base metal and gold properties in Canada. Thundermin also has royalty interests in a further 28 base metal and gold properties located in Manitoba, Saskatchewan, British Columbia and Quebec, the most significant being a 2.5% net smelter return royalty in the Pelletier Lake gold deposit which is under option to Alexis Minerals Corporation. Thundermin also has various shareholdings in thirteen other junior resource companies that are actively exploring for base metal, gold, chrome, vanadium-titanium and diamond deposits in Canada.

Forward-Looking Statements

This news release may contain "Forward-Looking Statements" that involve risks and uncertainties, such as statements of Thundermin's plans, objectives, strategies, intentions and expectations. The words "potential," "anticipate," "forecast," "believe," "estimate," "expect," "may," "project," "plan," and similar expressions are intended to be among the statements that identify "Forward-Looking Statements". Although Thundermin believes that its expectations reflected in these "Forward-Looking Statements" are reasonable, such statements may involve unknown risks, uncertainties and other factors disclosed in our regulatory filings that can be viewed on the SEDAR website at www.sedar.com. For us, uncertainties arise from the behavior of financial and metals markets and from numerous other matters of national, regional, and global scale, including those of an environmental, climatic, natural, political, economic, business, competitive, or regulatory nature. These uncertainties may cause our actual future results to be materially different than those expressed in our "Forward-Looking Statements". Although Thundermin believes the facts and information contained in this news release to be as correct and current as possible, Thundermin does not warrant or make any representation as to the accuracy, validity or completeness of any facts or information contained herein and these statements should not be relied upon as representing its views subsequent to the date of this news release.

For further information on Thundermin Resources Inc. please visit Thundermin's website at www.thundermin.com or the SEDAR website at www.sedar.com.

To view Figure 1, please visit the following link: http://media3.marketwire.com/docs/Figure1-THR.pdf.