Minefinders Corporation Ltd.

Minefinders Corporation Ltd.

February 28, 2005 09:01 ET

Minefinders Discovers More Silver in Sonora, Mexico


NEWS RELEASE TRANSMITTED BY CCNMatthews

FOR: MINEFINDERS CORPORATION LTD.

TSX SYMBOL: MFL
AMEX SYMBOL: MFN

FEBRUARY 28, 2005 - 09:01 ET

Minefinders Discovers More Silver in Sonora, Mexico

VANCOUVER, BRITISH COLUMBIA--(CCNMatthews - 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


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Contact Information

  • FOR FURTHER INFORMATION PLEASE CONTACT:
    Minefinders Corporation Ltd.
    Mark H. Bailey
    President and Chief Executive Officer
    1 (866) 687-6263
    (604) 687-6267 (FAX)
    www.minefinders.com