SOURCE: Oriental Minerals Inc.

May 02, 2007 09:00 ET

Oriental Drilling Confirms Continuity of Significant Tungsten-Molybdenum Mineralization at Sangdong

VANCOUVER, BC -- (MARKET WIRE) -- May 2, 2007 -- Oriental Minerals Inc. (TSX-V: OTL) is very pleased to announce complete drill results received from the Company's third drill hole at the Sangdong tungsten-molybdenum project in South Korea. These results from SD-03 confirm that highly significant grades and thicknesses of disseminated tungsten-molybdenum mineralization are present. Highlights include an intercept of 4 metres grading 0.41% tungsten oxide (WO3). Hole SD-03 also confirmed the continuity of mineralization, with a 141-metre interval averaging 0.10% tungsten oxide and 0.02% molybdenum sulphide, starting just 15 metres from surface.

Diamond drill hole SD03 was designed to drill test the entire 135-metre thick skarn package (23m-158m) approximately 450 metres up-dip from the Company's first hole SD-01. SD-03 was also designed to drill test the potential for up-dip extensions from the historical molybdenum resource hosted within the Jangsan Quartzite below the skarn package.

Please visit www.orientalminerals.com to view an updated drill-hole map and long section for Sangdong. Results from hole SD-03 are tabulated below:

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Intersection  Depth    WO3(%)  Mo(%) MoS2(%)         Formation
Thickness
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22 metres    15-37m    0.22    0.04  0.07    Skarn-altered Myobong Slate
2 metres     64-66m    0.17    0.00  0.01    Skarn-altered Myobong Slate
12 metres    71-83m    0.24    0.01  0.01    Skarn-altered Myobong Slate
1 metre      87-88m    0.23    0.00  0.01    Skarn-altered Myobong Slate
2 metres     96-97m    0.22    0.00  0.00    Skarn-altered Myobong Slate
3 metres     105-108m  0.18    0.03  0.05    Skarn-altered Myobong Slate
3 metres     110-113m  0.13    0.00  0.00    Skarn-altered Myobong Slate
2 metres     115-117m  0.09    0.00  0.00    Skarn-altered Myobong Slate
4 metres     122-126m  0.41    0.00  0.00    Skarn-altered Myobong Slate
4 metres     133-137m  0.16    0.00  0.00    Skarn-altered Myobong Slate
10 metres    147-157m  0.15    0.00  0.00    Skarn-altered Myobong Slate
5 metres     179-184m  0.08    0.06  0.10    Jangsan Quartzite
1 metre      202-203m  0.17    0.00  0.00    Jangsan Quartzite
1 metre      237-238m  0.03    0.16  0.27    Jangsan Quartzite
12 metres    248-260m  0.12    0.00  0.00    Jangsan Quartzite
1 metre      326-327m  0.13    0.00  0.00    Jangsan Quartzite
1 metre      336-337m  0.20    0.00  0.00    Jangsan Quartzite
1 metre      352-353m  0.15    0.00  0.00    Jangsan Quartzite
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The mineralized intersections hosted in the skarn-altered Myobong Slate closely correlate with bedding-concordant quartz-scheelite veins and as such represent near true-width intersections.

Tungsten-molybdenite mineralisation has also been logged in holes SD-4 and SD-06, situated a further 280 metres up-dip from hole SD-03. This indicates tungsten-molybdenum mineralization has been intersected in drilling over at least 730 metres length. This has very important implications, both in terms of the amount of mineralization and the choice of a future mining method. SD-03 intersected quartz-scheelite vein stockworks in the skarn-altered Myobong Slate, between 23-158 metres downhole, and Jangsan Quartzite with sporadic quartz-scheelite-molybdenum veins from 158 to 360 metres.

The second hole at Sangdong SD-02 was abandoned after hitting old workings associated with the Hangingwall Vein at 202 metres depth. A "wedge" was made at 120 metres and SD-02B drilled in an attempt to penetrate these workings. SD-02B was also abandoned, at 180 metres, when it too failed to penetrate these workings. Results from the completed portion of SD-02 are still pending.

Hole SD-04 reached its targeted depth of 225 metres. It intersected skarn with tungsten-molybdenum mineralization from 0-144 metres, then Jangsan Quartzite containing traces of wolframite-molybdenite mineralisation to end of hole. SD-04 is sited 280 metres up-dip of SD-03.

The fifth hole at Sangdong SD-05 was abandoned at 20 metres after hitting old workings associated with the Hangingwall Vein.

Hole SD-06 reached its targeted depth of 300 metres. It intersected skarn with tungsten-molybdenum mineralization from 0-111 metres, then Jangsan Quartzite containing traces of wolframite-molybdenite mineralisation to end of hole. SD-06 is sited 112 metres up dip of SD-03.

Holes SD-07 is currently at 70 metres depth, SD-08 at 35 metres depth and SD-09 at 9 metres depth.

Five drill rigs are now operational on site, including an Australian-sourced Longyear 38, together with all ancillary equipment. A large Australian-sourced track-mounted RD1000 Reverse Circulation-Diamond drill rig and track mounted compressor is en-route to the nearby city of Busan. The imminent arrival of the RD1000 Reverse Circulation-Diamond drill rig offers the potential to penetrate the Hangingwall Vein workings, rapidly drill through Pungchon Limestone cover, as well as the ability to drill the deeper holes that are necessary to fully test the Deep Moly historical resource. Abandoned holes SD-02 and SD-05 will be redrilled using this drill rig.

The Main Vein at Sangdong formed the basis for the majority of the historical mining by the Korean Tungsten Co., Ltd during 1947-1992. Detailed mine plans suggest approximately 30% of the Main Vein was left behind as roof pillar support, as estimated by the historical resource reported by KORES.

Click Below to view the Sangdang Mine Phase II Drilling Program.

http://www.usetdas.com/maps/orientalminerals/oriental.jpg

Graphic Hosting Provided by Filing Services Canada Website.

Widespread disseminated molybdenum mineralization has been intersected below the skarn package within the Jangsan Quartzite. This mineralization is associated with narrow bedding-concordant quartz-molybdenite veins with occasional sub-vertical vein structures. Drill hole SD-01 has confirmed that a major molybdenum mineralized system is clearly present at the Sangdong mine.

Previous underground drilling (22 diamond drill holes) by Korean Tungsten Co., Ltd and KORES formed the basis for the historical resource estimate of the deep molybdenum deposit beneath the historical tungsten mine workings.

Note: Samples are 1-metre split HQ core samples and were submitted to ALS Chemex laboratory in Brisbane, Australia and analyzed by Ore Grade Method XRF-ME05, Au-AA21, ME-ICP41s and Ag-OG46. Quality Control: Blanks and Standards samples were routinely inserted with the drill samples at random intervals. Analysis of Standards indicates the laboratory results are all within +/-5% of certified assays and so results are considered reliable. Blank samples were clean, indicating no cross contamination in the samples.

QUALIFIED PERSON

The qualified person for the purposes of this release is Mr. Mark Dugmore.

On behalf of the Board of Directors,
Damien Reynolds
Chairman and Director
Statements in this news release, other than purely historical information, including statements relating to the Company's future plans and objectives or expected results, constitute forward-looking statements. Such statements are based on numerous assumptions and are subject to all the risks and uncertainties inherent in the Company's business, including risks related to mineral exploration and development. Consequently, actual results may vary materially from those described in the forward-looking statements.

The TSX Venture Exchange does not accept responsibility for the adequacy or accuracy of this release.

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