Wed Jan 23, 2013
Goldrock Mines Corp. Now Trading - Feasibility Study Progress and Arizaro Drilling Update

Vancouver, British Columbia -- Goldrock Mines Corp. (TSX.V -- GRM)
NR 12-01

Goldrock Mines Corp. (the "Company") announces that the TSX Venture Exchange (the "Exchange") has approved a change of the Company's name from Mansfield Minerals Inc. to Goldrock Mines Corp. Effective today, the common shares of the Company have commenced trading on the Exchange under the new trading symbol "GRM". The share capital of the Company remains unchanged. Goldrock recently enhanced its management team and under the new Goldrock banner is pursuing a long-term objective to become an annual 250,000 ounce gold producer, both organically through the development of its existing properties and by the acquisition of near-term production assets through purchase or merger.

The Company is also pleased to advise on the progress of the Lindero heap leach gold project feasibility study which is due for completion in the first quarter of 2013. The 100% owned Lindero deposit is located in Salta Province, Argentina. The Company has been granted the environmental permit (DIA, Declaracion de Impacto Ambiental) by the Salta Provincial Government allowing the Company to develop the Lindero open pit, heap leach gold mine. This is the primary permit required for project development. The Company has retained Kappes Cassiday and Associates to serve as lead consultant, working in collaboration with AMEC and Mine Development Associates (MDA Reno) to produce the full feasibility study.

A range of project development alternatives have been assessed with the objectives of maximizing economic return while delivering a robust life of mine gold production profile, maximizing early cash flow, and minimizing initial capital. Various alternate mining rates and processing strategies were studied, including initial processing of higher grade gold resources at reduced throughput with lower initial capital, followed by scaling up of operations utilizing the early project cash flow. After rigorous technical and economic analysis to establish the optimum value curve for the project, the Company has determined that an initial processing rate of 15,000 tpd for the first 3 years, taking advantage of the near surface higher grade resources and followed by an incremental capital efficient expansion to 18,750 tpd, provides an optimum development strategy. The detailed development plans will be further reviewed and optimized as the feasibility study work is finalized.

A detailed mine plan utilizing contract mining for the first 3 years has been completed. This will minimize upfront capital during a period where low total material movements are required due to the low ore to waste strip ratio, and will be followed by a change over to a larger capacity owner-operated mining fleet. Quotes for the supply of the administration offices, laboratory, warehouse, reagent storage, open pit mine workshop and a 400-person camp have all been received from Argentinean suppliers.

The Company has also determined that a gas fired power station with gas transport by dual trailer trucks to site, instead of the construction of a 120 kilometer gas pipeline, provides the most economical source of electric power for the project. As part of this work package, the estimated cost to upgrade the existing road between Pocitos (where the gas compressor station will be located on the Salta - Puna gas pipeline) to Lindero has been obtained.

The Company, with its consultants, anticipates concluding and reporting final results of the feasibility study by March 2013. As the Company has a mining license in hand, it is now pursuing project financing for mine construction.

Goldrock has now concluded a 2,983-metre (13 holes) diamond drilling program on its Arizaro gold-copper porphyry discovery located three kilometres southeast of Lindero. The near-surface oxide gold potential of the Arizaro porphyry system is being assessed as a potential add-on that could significantly extend the Lindero mine life and/or increase Lindero's annual production profile. The focus of the drill program was to test lateral and depth extensions of the shallow (less than 300 metres vertical) gold mineralization previously encountered (see news releases dated November 1, 2011, DDH ARD-13: 122 metres at 0.75 g/t gold and 0.24% copper and January 8, 2013, DDH ARD-18: 44 metres at 0.80 g/t gold and 0.22% copper). The assays from the remaining 8 holes are expected by the end of the month with a 43-101 report anticipated sometime in the second quarter of 2013.

ON BEHALF OF THE BOARD OF DIRECTORS,

"Paul Matysek"

Paul Matysek, M.Sc., P.Geo
President and CEO

For additional information:

604. 681.4462
info@goldrockmines.com
www.goldrockmines.com

Qualified Person:

David Keough FAusIMM(CP) of Goldrock Mines Corp. is a "qualified person" as such term is defined in National Instrument 43-101 (Standards of Disclosure for Mineral Projects) and has reviewed and approved the technical information and data included in this press release.

Neither the TSX Venture Exchange, nor its Regulation Services Provider accepts responsibility for the adequacy or accuracy of this release.

Caution Regarding Forward-Looking Statements

This press release includes certain statements that may be deemed "forward-looking statements". All statements in this discussion, other than statements of historical facts, that address future exploration drilling, exploration activities, anticipated metal production, internal rate of return, estimated ore grades, commencement of production estimates and projected exploration and capital expenditures (including costs and other estimates upon which such projections are based) and events or developments that the Company expects, are forward looking statements. Although the Company believes the expectations expressed in such forward looking statements are based on reasonable assumptions, such statements are not guarantees of future performance and actual results or developments may differ materially from those in forward-looking statements. Factors that could cause actual results to differ materially from those in forward-looking statements include metal prices, exploration success, continued availability of capital and financing, and general economic, market or business conditions. Accordingly, readers should not place undue reliance on forward-looking statements.

This news release and the information contained herein does not constitute an offer of securities for sale in the United States and securities may not be offered or sold in the United States absent registration or exemption from registration,
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