Minefinders Discovers More Silver in Sonora, Mexico

    Business Editors

    VANCOUVER, British Columbia--(BUSINESS WIRE)--Feb. 28, 2005--Minefinders Corporation Ltd. (the "Company") (TSX:MFL)(AMEX:MFN); Mark H. Bailey, President and CEO, reports results from recent drilling at the Company's 100% owned Real Viejo and Planchas de Plata projects, located in northern Sonora, Mexico. A total of 28 reverse-circulation drill holes, totaling 3,010 meters (9,875 ft), were completed at the two projects. The recent drilling expanded mineralization encountered at Real Viejo during an earlier drill program (NR 6-9-04) and was the initial testing of mineralization at several areas of historic mining at Planchas de Plata.

    Real Viejo

    The 22 holes completed at Real Viejo targeted the 600 meter long zone of mineralized stockworks, originally tested by the Company in the spring of 2004. The early 2004 drilling consisted of five widely spaced core holes that intersected multiple zones of silver mineralization. Intercepts from this program were reported in the Company's news release dated September 6, 2004 and included 27.5 meters averaging 158.7 grams per ton("gpt") silver ("Ag") (4.6 ounces per ton silver over 90.2 feet), including 634 gpt over 1.3 meters.

    The follow-up reverse-circulation drill program was designed to offset previous intercepts and test several additional sub-parallel zones. Of the 22 holes completed, 20 holes intersected significant silver mineralization, often with associated base metal (copper, lead, zinc) mineralization. Of note is drill hole RV04-8, which was drilled approximately 80 meters west of hole RV04-4C, one of the initial core holes containing high grade silver mineralization. Drill hole RV04-8 contained five 1.5 meter intervals grading higher than 1000 gpt Ag including the interval from 97.5 to 99 meters that assayed 2,640 gpt (77 ounces per ton silver over 5 feet). These intervals occurred within several wider zones of mineralization including from the surface to 7.6 meters that averaged 370.3 gpt Ag over 7.6 meters (10.8 ounces per ton silver over 25 feet) and from 25.9 to 117.4 meters that averaged 211.4 gpt Ag over 91.5 meters (6.17 ounces per ton silver over 300 feet). A summary of drill intercepts from the 22 holes is shown in the accompanying Table 1 and is available on Minefinders' website (www.minefinders.com).

    The drilling confirmed the continuity of the zone as well as identified higher-grade portions. Drill hole RV04-7, drilled in the east central portion of the zone, intersected a previously-unidentified, large, concealed rhyolite plug that may be directly associated with mineralization and be the reason for the higher-grade intercepts found in holes RV04-8, RV04-5, RV04-1, and RV04-13/RV04-4C. Future geologic mapping and cross sectional interpretation will focus on understanding the controls to high-grade mineralization in order to guide further drilling.

    Planchas de Plata

    At the Planchas de Plata project, a total of six holes were completed within two areas of historic mining. The drilling twinned four historic drill holes completed in the early 1970s (data released in news release dated January 12, 2005) and tested for the presence of inferred feeder structures. The drill results confirm the presence of high-grade silver mineralization along northeast-trending feeder structures and indicate that previously-identified lower-grade zones may have been a result of downhole contamination related to the percussion drilling procedures utilized in the 1970s program. All holes that intersected the inferred feeder structures returned significant silver values including hole PP05-4, which returned 21.4 meters averaging 167.8 gpt Ag from 19.8 to 41.2 meters (4.89 ounces per ton silver over 70 feet). This interval included 975 gpt Ag over 1.5 meters (28.44 ounces per ton silver over 5 feet). A summary of drill intercepts from the six holes is shown in the accompanying Table and is available on Minefinders' website (www.minefinders.com).

    Minefinders is currently contracting a drill rig to continue exploration of the Planchas de Plata and Real Viejo projects. New drilling at Planchas de Plata is expected to target three additional areas of historic mining as well as test the extensions of major feeder structures. Geologic mapping and sampling at Planchas de Plata is continuing to identify and extend mineralized structures beyond areas of historic mining and drilling. In addition, existing drilling has only been completed to shallow depths, leaving significant untested potential at depth. Drill data from Real Viejo is currently being compiled and interpreted. Additional drilling is anticipated to extend the high-grade mineralization and test structural intersections.

    Minefinders' Northern Sonora Concessions encompass much of a major, regional, northwest mineralized trend. This trend contains the Real Viejo and Planchas de Plata silver properties as well as the Company's La Bolsa gold-silver deposit. The Company has made a significant exploration investment in these concessions with a view to realizing the substantial capital and operating cost benefits that should be possible from their joint development.

    Drill samples, weighing between 5 kg and 15 kg each, were collected and transported from the Real Viejo and Planchas de Plata sites for assay by ALS-Chemex Labs of Vancouver, B.C. Standards are inserted into the sample stream for quality control and a duplicate sample is maintained at the project site for check assay and metallurgical testing. Reverse-circulation drilling was conducted by Layne de Mexico based in Hermosillo Sonora.

    Mark H. Bailey, MSc., P.Geo., a Qualified Person as defined by National Instrument 43-101, has overall responsibility for the Company's mineral exploration programs and supervised the preparation of the technical information in this news release.

    MINEFINDERS CORPORATION LTD.

    Mark H. Bailey

    President and Chief Executive Officer

    All resource estimates referred to in this disclosure are calculated in accordance with the Canadian National Instrument 43-101 and the Canadian Institute of Mining and Metallurgy Classification system. These standards differ significantly from the requirements of the United States Securities and Exchange Commission, and resource information reported in this disclosure may not be comparable to similar information reported by United States Companies. The terms "Resource(s)" does not equate to "reserves" and normally may not be included in documents filed with the Securities and Exchange Commission.

    Safe Harbor Statement under the United States Private Securities Litigation Act of 1995: Statements in this release that are forward-looking, including statements relating to the size, and growth in size, of Minefinders' mineral resources and the timing of the further exploration and development of its exploration projects, are subject to various risks and uncertainties concerning the specific factors identified above and in the company's periodic filings with the Ontario Securities Commission and the U. S. Securities Exchange Commission. Such information contained herein represents management's best judgment as of the date hereof based on information currently available. Minefinders does not intend to update this information and disclaims any legal liability to the contrary.

Table: 1 Real Viejo Drilling 2004 Results

From To Width Drill me- me- me- Silver Pb Zn Cu hole ters ters ters feet g/t oz/t ppm ppm ppm RV04-1 0 13.7 13.7 45 49 1.43 2885 529 424

RV04-2 3.1 10.7 7.6 25 15.2 0.44 792 5637 68

RV04-3 18.3 22.9 4.6 15 12.7 0.37 810 2052 74 and 44.2 47.2 3 10 16.6 0.48 1494 657 124 and 57.9 59.4 1.5 5 88.3 2.58 3710 158 509

RV04-4 0 6.1 6.1 20 19.4 0.57 1775 750 151

RV04-5 0 29 29 95 50 1.46 2752 649 413 and 50.3 74.7 24.4 80 52 1.52 3048 2294 398 and 100.6 102.1 1.5 5 67.5 1.97 4330 698 2280

RV04-7 27.5 30.5 3 10 22 0.64 1098 449 191 and 47.2 57.9 10.7 35 25.4 0.74 2398 925 132 and 70.1 79.2 9.1 30 19.9 0.58 1813 978 57 and 82.3 86.9 4.6 15 18.9 0.55 6600 1183 38

RV04-8 0 7.6 7.6 25 370.3 10.80 1837 650 1343 including 1.5 3 1.5 5 1605 46.81 5100 595 5720

and 25.9 117.4 91.5 300 211.4 6.17 9495 745 1213 including 88.4 105.2 16.8 55 651.1 18.99 12791 828 3754 including 97.5 99 1.5 5 2640 77.00 68200 665 11000

RV04-8A 9.2 12.2 3 10 21.4 0.62 3895 789 260

RV04-10 3.1 4.6 1.5 5 46.8 1.36 1945 775 208 and 18.3 25.9 7.6 25 21.9 0.64 607 367 151

RV04-11 12.2 27.4 15.2 50 30.4 0.89 2323 837 414 and 38.1 39.6 1.5 5 331 9.65 312 525 1365 and 74.7 77.7 3 10 58.3 1.70 2390 1295 291

RV04-12 6.1 10.7 4.6 15 48.5 1.41 1195 547 451 and 19.8 24.4 4.6 15 25.8 0.75 1020 1226 220 and 39.6 51.8 12.2 40 49.4 1.44 2139 2510 254 and 82.3 83.8 1.5 5 58.6 1.71 1395 3310 575

RV04-13 19.8 30.5 10.7 35 150.1 4.38 8600 1574 1241 Twin of RV04-4C including 21.3 24.3 3 10 258.5 7.54 17830 1047 1908

and 73.2 93 19.8 65 70.3 2.05 2595 680 500 including 77.7 82.3 4.6 15 124.6 3.63 1502 705 816

RV04-14 19.8 32 12.2 40 14.9 0.43 937 1533 86

RV04-15 0 18.3 18.3 60 12.3 0.36 2143 2053 80 and 35.1 36.6 1.5 5 81.9 2.39 33700 7780 229 and 65.5 68.5 3 10 126.1 3.68 14860 2188 678 and 86.9 89.9 3 10 30.5 0.89 3375 2185 110

RV04-16 0 25.9 25.9 85 23.7 0.69 3490 760 122 Includes 3 m mine working including 13.7 15.2 1.5 5 95.3 2.78 6300 806 116

RV04-17 0 6.1 6.1 20 28.3 0.83 2185 1018 216 and 13.7 33.5 19.8 65 91.1 2.66 4094 1220 428 Includes 3 m mine working including 15.2 19.8 4.6 15 256.2 7.47 9730 802 428

and 71.6 77.7 6.1 20 37.8 1.10 2590 410 134

RV04-18 38.1 39.6 1.5 5 76.9 2.24 5960 1170 990 and 144.8 149.4 4.6 15 28.4 0.83 2112 1622 141 and 163.1 172.2 9.1 30 32.9 0.96 1923 803 204

RV04-19 99.1 105.2 6.1 20 19.7 0.57 987 1004 66

RV05-20 32 35 3 10 46.9 1.37 6230 9435 175

RV05-21 0 4.6 4.6 15 12.8 0.37 2017 603 85

Planchas de Plata Drilling 2005 Results

From To Width Drill me- me- me- Silver Pb Zn Cu hole ters ters ters feet g/t oz/t ppm ppm ppm PP05-1 3.1 18.3 15.2 50 114.3 3.33 106 378 199 including 7.6 15.2 7.6 25 191.4 5.58 147 403 339

PP05-2 30.5 32 1.5 5 43.7 1.27 40 259 44

PP05-4 19.8 41.2 21.4 70 167.8 4.89 976 464 885 including 33.5 35 1.5 5 975 28.44 481 328 7040

PP05-5 12.2 15.2 3 10 47.2 1.38 951 347 174 and 38.1 45.7 7.6 25 249.3 7.27 1400 455 1553 including 39.6 42.6 3 10 540.5 15.76 2580 549 3645

PP05-6 0 1.5 1.5 5 69.6 2.03 282 221 122

    Minefinders Corporation Ltd. (TSX:MFL) (AMEX:MFN)

--30--SH/na*

CONTACT: Minefinders Corporation Ltd. Mark H. Bailey President and Chief Executive Officer 1 (866) 687-6263 Fax: (604) 687-6267 www.minefinders.com

KEYWORD: NEW YORK INTERNATIONAL CANADA INDUSTRY KEYWORD: MINING/METALS SOURCE: Minefinders Corporation Ltd.

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