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Message: 39% Increase in Tasiast Reserves (119% Since August 2007)
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39% Increase in Tasiast Reserves (119% Since August 2007)

posted on Mar 24, 2009 08:18AM
March 23, 2009
Red Back Mining Inc.: 39% Increase in Tasiast Reserves (119% Since August 2007)
VANCOUVER, BRITISH COLUMBIA--(Marketwire - March 23, 2009) - Red Back Mining Inc. (the "Company" or "Red Back") (TSX:RBI) is pleased to announce a significant increase in Proven and Probable Reserves at its 100% owned Tasiast Gold Mine ("Tasiast") in Mauritania and a similar increase in Measured and Indicated Resources.

Tasiast Reserves

The Company's consultants, AMC Consultants, have re-estimated Ore Reserves for the Tasiast mine. The new Ore Reserve estimate, shown in the table below, is reported as at 31 December 2008.

----------------------------------------------------------
                         Tonnes           Au    In situ Au
Classification              (Mt)        (g/t)         (Moz)
----------------------------------------------------------
Total Proven               27.2         1.48          1.30
Total Probable             20.1         1.46          0.94
Total Stockpile             1.7         0.89          0.05
----------------------------------------------------------
Total                      49.0         1.45          2.28
----------------------------------------------------------
- Numbers may not add correctly due to rounding
- The Ore Reserve estimate was made using a gold price of US$700, no change
  from previous Ore Reserve estimate
- Cut-off grades: CIL oxide 0.78g/t, CIL fresh 0.86g/t, Dump leach oxide
  0.12g/t.
The reserve represents a 39% increase over the previously reported reserve (News Release: April 7, 2008). Red Back has now increased reserves at Tasiast by 119% in the 19 months since it acquired the project in August 2007.

The current Ore Reserves include the CIL and Dump Leach components for Piment and the CIL component for West Branch (refer to attached Map for location of deposits).

To view the attached map, please click on the following link: http://media3.marketwire.com/docs/rb... .

The estimated split of reserves by processing method is set out below:

----------------------------------------------------------
                         Tonnes           Au    In situ Au
Classification              (Mt)        (g/t)         (Moz)
----------------------------------------------------------
CIL Circuit
----------------------------------------------------------
Proven                     17.8         2.05          1.18
Probable                   13.7         1.95          0.86
Stockpile                   0.9         1.17          0.03
----------------------------------------------------------
Total CIL Circuit          32.4         1.99          2.07
----------------------------------------------------------

----------------------------------------------------------
Dump Leach
----------------------------------------------------------
Proven                      9.4         0.40          0.12
Probable                    6.3         0.38          0.08
Stockpile                   0.8         0.61          0.02
----------------------------------------------------------
Total Dump Leach           16.5         0.40          0.21
----------------------------------------------------------
- Numbers may not add correctly due to rounding
- Piment zone oxide ore between 0.12g/t and 0.90g/t was allocated to the
  Dump leach Process.
A Dump Leach operation to process low grade oxide ore from the Piment zone is in its final stages of commissioning, with commercial levels of recoveries expected in the second quarter.

Test work is ongoing to extend the oxide Dump Leach reserves to include material from the West Branch area. In addition, following positive initial results, test work to investigate the potential for heap leaching low grade fresh material is also being accelerated. Upon completion of this test work, low grade oxide and fresh material from West Branch and low grade fresh material from Piment is expected to be converted to Ore Reserves. A new reserve estimate will be released in the third quarter incorporating this material.

Tasiast Resources

Measured and Indicated Resources, using a cut off grade of 1 g/t, have increased by 32% over the previously reported mineral resource estimate (News Release: June 12, 2008). The Company will now report resources on the basis of mining cut-off grades expected to be applied to the various ore types as well as at a 1 g/t cut-off grade for comparison purposes.

--------------------------------------------------------------------------
                                                Measured +
                   Measured      Indicated      Indicated      Inferred
                -------------- -------------- -------------- -------------
           Cut-        Au             Au             Au            Au
Zone       Off    Mt  g/t  Moz   Mt  g/t  Moz   Mt  g/t  Moz   Mt g/t  Moz
--------------------------------------------------------------------------
Oxide      0.2  19.0 0.98 0.60 15.9 0.77 0.39 34.9 0.89 0.99  7.0 0.6 0.13
--------------------------------------------------------------------------
Transition 0.5   5.0 1.28 0.20  4.3 1.13 0.16  9.2 1.21 0.36  0.9 1.1 0.03
--------------------------------------------------------------------------
Fresh      0.5  20.5 1.48 0.98 32.7 1.32 1.39 53.2 1.38 2.37 15.6 1.2 0.62
--------------------------------------------------------------------------

Total           44.5 1.24 1.78 52.9 1.14 1.94 97.4 1.19 3.72 23.6 1.0 0.78

--------------------------------------------------------------------------

--------------------------------------------------------------------------
All ore
 types     1.0  18.4 2.13 1.26 19.8 1.99 1.27 38.2 2.06 2.53  7.4 2.0 0.47
--------------------------------------------------------------------------

- Minerals Resources are reported below the December 31 2008 mined surface.
- Figures may not add correctly due to rounding.
- Oxide is referred to as material amenable to Dump Leaching and comprises
  oxide plus upper transition. Transition is lower transition which with
  fresh material is potentially amenable to Heap Leaching.
- The resources are estimates of recoverable tonnes and grades using
  Multiple Indicator Kriging with block support correction into 15 metres
  (East) by 25 metre (North) by 5 metre (Elevation) model blocks and
  assuming smallest mining unit for ore selection in mine grade control of
  3 metres (East) by 5 metres (North) by 2.5 metres (Elevation).
- Measured resources lie in areas where drilling is available at a nominal
  25 x 25 metre spacing, Indicated resources occur in areas drilled at
  approximately 25 x 50 metre spacing and Inferred resources exist in areas
  of broader spaced drilling.
- Gold estimation and model blocks were constrained within geologically
  derived wireframes.
- Resources are inclusive of reserves.
Future Reserve/Resource growth

The current Measured and Indicated Resources are contained in a six kilometer length of strike of the sub-parallel Piment and West Branch structures. These structures have been traced by the Company over 20 km on surface and well over 70km via aerial geophysics. Only widely spaced step out drilling has been completed outside the current resource area. Current exploration programs are focused on the area 2km immediately to the South of the current resource area. The Tasiast structures remain highly prospective and Red Back intends to continue to provide resource and reserve updates on a regular basis.

Chirano

A resource/reserve update for the Company's Chirano Gold Mine in Ghana is expected before the end of the first quarter.
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