Oregon Energy is a 100% owned USA subsidiary of Energy Ventures, holding a portfolio of uranium deposits in the western USA.
Energy Ventures, though its wholly owned US subsidiary Oregon Energy LLC, owns four advanced uranium projects located in the western USA, all of which have been subject to significant historical exploration and have either current or historical resources. The most advanced of these projects is the Aurora uranium project located in southeast Oregon.
Oregon Energy is currently advancing feasibility studies of the Aurora project; exploring its other project areas in Nevada and Colorado to increase the Company’s resource base; and is actively evaluating other uranium opportunities in the western USA.
The Company's short term strategy is to acquire further technically viable projects, preferably with known or historical resources, in order to increase the total resource base. Subsequently, these projects will be advanced through feasibility studies and into commercial production.
Oregon Energy Project Portfolio
Oregon Energy recently acquired the Aurora uranium deposit in southern Oregon from Uranium One Incorporated, for US$2 million in cash. The deposit has an updated total resource base of 38 Mlb eU3O8 comprising an Indicated Resource of 36.7 Mlb eU3O8 at a grade of 253 ppm eU3O8, and an Inferred Resource of 1.2 Mlb eU3O8 at a grade of 151 ppm eU3O8. The Aurora project is a near-surface volcanic hosted uranium deposit at an advanced exploration stage and is undergoing a pre-feasibility evaluation.
Oregon Energy has staked claims nearby to Aurora in the state of Nevada, covering the historical Virgin Valley uranium project, which is interpreted to be in another volcanic hosted system. Locally high-grade mineralisation up to 1% U is documented from surface rock chip samples and mineralisation is known to occur over about 2km2.
The Company has also staked new claims over two projects in the northwestern part of Colorado, an area known historically for uranium mining and for present day coal and natural gas production, power generation and ranching. The large Maybell uranium project encompasses a historical mining area with recorded historical production of over 5.3 Mlb of U3O8 and is located approximately 40km west of the town of Craig, Colorado.
The Skull Creek uranium project is located approximately 110km west of the town of Craig and about 75km west of the Company’s Maybell uranium project. The project is situated in an active coal mining area and the Company is targeting a near surface uranium resource along 15km of known mineralised strike length.
Aurora Project
The Aurora project is located in a historical mining area in southern Oregon, approximately 5km north of the Nevada border and approximately 15km west of the small border town of McDermitt, Nevada. The project consists of 133 contiguous, unpatented lode claims covering an area of approximately 1,125 hectares. The Company has also applied for a 259 Ha (one square mile) State of Oregon Exploration Permit adjacent to the lode claims.
The Aurora uranium deposit is most recently described in a report entitled "Technical Report of the Aurora Uranium Project, Malheur County, Oregon", prepared for Quincy Energy Corporation and dated 1 September, 2005. This report has been prepared in accordance with Canadian National Instrument 43-101 (NI43-101) and is available from the Canadian Security Administrators on the SEDAR filing system (www.sedar.com).
Uranium mineralisation at Aurora is hosted in clay altered volcanic flows and tuffs within the McDermitt Caldera complex. The mineralisation occurs as multiple strata-bound and cross-cutting bodies in the volcanic units, forming a flatlying to gently dipping, northwest-trending mineralised zone approximately 1.5km long by 300m wide. The mineralised horizons range from a true thickness of a few metres to more than 30m and are interpreted to represent both primary and secondarily enriched uranium bodies which are controlled by porous and permeable stratigraphic units and structural zones.
Exploration History
The Aurora deposit was discovered in 1977 through follow-up of anomalies detected on an airborne radiometric survey. The deposit was intensively explored by Placer Amex Corporation ("Placer") up to 1980. The work completed included a total of 537 rotary drill holes and 25 diamond drill holes, delineating the mineralisation on a 60m by 30m grid spacing. All drill holes were radiometrically logged and a number of samples were chemically assayed. Placer progressed metallurgical testing and other feasibility studies on the deposit but ultimately withdrew from the project due to a decline in the uranium price. Uranium One acquired a 100% interest in the Aurora project area in 2007 as a consequence of a corporate takeover of Energy Metals Corporation.
Mineral Resource
The resource estimate for the Aurora deposit has outlined an Indicated Resource of 65.7 Mt @ 253 ppm eU3O8 (36.7 Mlb eU3O8) and an Inferred Resource of 3.6 Mt @ 151 ppm eU3O8 (1.2 Mlb eU3O8). This resource represents a total of 38 Mlb eU3O8.
The term eU3O8 refers to an equivalent uranium oxide grade that is based on the conversion of a radiometric gamma log determination of radioactive mineral abundance to a calculated uranium content. True U3O8 values are obtained from direct chemical assay results.
| Indicated Resource | Inferred Resoource | Total Resource | |||||||
| Resource Zone | Mt |
eU3O8
(ppm)
|
Mlb
(eU3O8)
|
Mt |
eU3O8
(ppm)
|
Mlb
(eU3O8)
|
Mt |
eU3O8
(ppm)
|
Mlb
(eU3O8)
|
| High Grade Zone1 | 18.4 | 444 | 18.0 | - | - | - | 18.4 | 444 | 18.0 |
| Low Grade Zone2 | 47.3 | 179 | 18.7 | 3.6 | 151 | 1.2 | 50.9 | 177 | 19.9 |
| Total | 65.7 | 253 | 36.7 | 3.6 | 151 | 1.2 | 69.3 | 248 | 37.9 |
The resource contains a high-grade portion of 18.4 Mt @ 444 ppm eU3O8 based on an interpreted grade envelope defined by a 300 ppm eU3O8 cut-off grade. This zone contains 18.0Mlb of eU3O8, which compares favourably with the previously quoted Indicated Resource for the deposit.
A broad zone of lower grade resource surrounds and lies immediately below the high-grade zone. This zone contains a further 50.9 Mt @ 177 ppm eU3O8 using an interpreted envelope defined by a cut-off grade of 100 ppm eU3O8. This previously unreported zone is estimated to contain a total of 19.9 Mlb eU3O8.
The geological and resource model for theAuroradeposit is based on detailed historical drilling that was drilled on a 60m by 30m grid spacing oriented perpendicular to the strike of the deposit. A total of 426 drill holes (including both diamond and rotary holes) were utilised to define the resource.
The resource model comprises a higher-grade core of stacked, sub-horizontal to gently dipping, tabular zones of mineralisation that locally coalesce into thicker bodies of mineralisation. This core, which shows continuity at a 300 ppm eU3O8 cut-off grade, is surrounded by a large, lower-grade halo of mineralisation that extends the overall zone of mineralisation to a depth of 180m below surface and is open along strike and to the northwest. The substantial increase in the revised resource size is largely attributable to the incorporation of this lower-grade zone.
Uranium oxide grade is based on historical down-hole geophysical radiometrics (gamma log), both continuous and so-called point measurements. eU3O8 grades were validated against historical geochemical assays of diamond core samples collected from within the deposit, with overall good correlation between the radiometric assaying and the chemical assays.
Statistical analyses on the accumulated composites were completed and outliers reduced where appropriate. Variography and search neighbourhood analysis were also conducted as input into the grade estimation. The grade estimation method used was Block Ordinary Kriging.
Historical geochemical Estimates of dry insitu bulk density are based on historical records produced from several hundred core samples distributed through the deposit. The average dry insitu bulk density used for the resource estimate is 1.9t/m3.
Resource classification was developed from the confidence levels of key criteria including drilling method, geological understanding and interpretation, grade analysis, data density and location, grade estimation and quality.
Current Work Programme
The Company is undertaking further diamond drilling on the Aurora deposit to advance the understanding of the grade and continuity of mineralisation; confirm downhole radiometric grades and obtain further samples for metallurgical testing. The results of this work will ultimately be incorporated into feasibility studies to evaluate the economic viability of the project.
Further programmes of reverse circulation (RC) drilling will also be undertaken to test extensional targets adjacent to the Aurora deposit. The strike extensions of the structures that appear to control the mineralisation at Aurora are inferred to continue beyond the original tenement area and are poorly tested.
A systematic review of other uranium targets in the vicinity of the Aurora project has also identified areas with the potential to increase available resources through discovery of new mineralised zones. Further claims will be staked in surrounding areas to allow exploration of these targets.
Virgin Valley Project
The Virgin Valley uranium project is located in northwest Nevada, USA. The Company holds 37 federal lode claims that comprise a total of approximately 740ha, and which cover a known historical uranium prospect hosted in volcanic rocks and associated sedimentary units within a volcanic caldera complex. The project is located in an active mining area, approximately 500km north of Reno and approximately 100km west of the Company’s Aurora uranium project in Oregon. The project is readily accessible by state highways and local all-weather roads.
The geology of the Virgin Valley project and the occurrences of uranium mineralisation are documented in Open File Report 96-3 available from the Nevada Bureau of Mines and Geology (see www.nbmg.unr.edu). Geological mapping indicates that the area is located within a volcanic caldera, similar to the McDermitt Caldera in Oregon which hosts the Aurora uranium deposit. Uranium mineralisation at Virgin Valley is present over an area of approximately 2km2 and is associated with a number of different geological units. The most radioactive occurrences were documented in a brecciated rhyolite unit which contained 0.269% U and 0.974% U in separate rock chip samples.
The mineralisation at Virgin Valley was explored in detail by Exxon Minerals in the 1970's, including programmes of drilling that culminated in a resource estimate for the deposit. Oregon Energy is currently attempting to locate this historical data. Recent explorers in the area include Western Uranium Corporation (TSXV:WUC) who completed geological mapping and surface radiometric surveys in 2007 that identified several strongly radioactive anomalies.
The reports of uranium mineralisation at Virgin Valley, including locally high-grade material at surface, suggest that this project area has the potential for a significant uranium resource. Work has commenced on the compilation of historical exploration information from the Virgin Valley project and surrounding areas. Subject to obtaining the necessary statutory exploration permits, the Company plans to undertake an exploration programme at Virgin Valley in order to verify the location and grade of uranium mineralisation that is reported in the area.
Maybell Project
The Maybell uranium project has been staked by the Company over an area in northwest Colorado that contains historical uranium mines and other known mineralised occurrences. The project comprises a total of 536 lode claims, covering approximately 4,330ha, and is located approximately 40km west of the town of Craig. Uranium mineralisation is widespread across the project area and occurs within an extensive sandstone unit. Oregon Energy intends to delineate a near-surface resource with potential for extraction by open pit mining methods.
Historical Production
According to a published study by Chenoweth (1986) the Maybell mining district has a total recorded historical production of over 5.3 Mlb of U3O8.
The Trace Element Corporation (subsequently merged into Union Carbide) operated a series of shallow open pit mines over an 11 year period between 1954 and 1964. Initial production of uranium was low (<100,000 lb U3O8) but production increased sharply in 1958 with the construction of an on-site mill. Between 1958 and 1964 when the mines were closed, the Maybell area produced between 500,000 and 720,000 lb U3O8 per year. Records of the US Atomic Energy Commission show that during the overall period the mines produced 1,629 thousand tons of ore at a grade of 0.13% U3O8 and containing approximately 4.3 Mlb U3O8.
When the price of uranium rose sharply in the mid-1970’s, Union Carbide resumed mining operations at Maybell. In 1976 the company commenced heap leaching of lower-grade material that had been left by previous mining operations. Leaching continued through to 1981, when mining and treatment ceased due to falling uranium prices. Approximately 1 Mlb of U3O8 was produced during this period.
Geological Potential
A characteristic feature of the uranium deposits at Maybell is the large halo of lower grade material that is widely distributed in the host rock sequence and surrounds higher grade concentrations which were the focus of previous exploitation. Uranium mineralisation occurs as near-surface zones hosted in tuffaceous sandstones of the Miocene Brown's Park Formation. These sandstone units vary from 60m to 300m total thickness and locally contain unusually thick zones (over 30m) of uranium mineralisation. Regionally, the mineralised sandstones occur within an extensive northwest trending area of uranium mineralised rocks approximately 13km long and 3km wide. The Company has secured the majority of this trend.
Uranium minerals occur as interstitial fillings in the sandstone, as grain coatings, and as minute inclusions in rock fragments. Primary uranium minerals are uraninite and coffinite, with a number of secondary uranium minerals in the oxidised zones. The geometry and physical characteristics of the permeable sandstones, combined with the uranium mineralogy suggests that they would be amenable to shallow open-pit mining and processing by a conventional heap leach process.
The US Department of Energy also studied the Maybell area in the 1970’s as part of the National Uranium Resource Evaluation (NURE) program for the determination of intermediate grade resources (0.01 to 0.05% U3O8). As part of this study 19 holes were drilled in the Maybell area, which suggested potential for a significant resource in an area of approximately 5km2 immediately north of one of the historical mines. The Company has secured this prospective area within the new claims and is currently sourcing the government reports on the work.
Current Work Programme
Oregon Energy has commenced work on the acquisition and compilation of historical exploration and drilling information from the Maybell project. Occurrences of near-surface uranium mineralisation have already been identified using a hand-held spectrometer and these areas have been targeted for priority drill testing. The Company also intends to undertake a detailed airborne radiometric survey over the project area.
Skull Creek Project
The Company acquired the Scull Creek uranium project from Uranium One Inc. in 2010. The project consists of 72 lode claims that cover an area of approximately 580ha and is located in north-western Colorado; approximately 110km west of the town of Craig and about 75km west of the Company’s Maybell uranium project. The project is situated in an active coal mining area.
The Skull Creek claims cover known uranium mineralisation hosted in lignite units interbedded with sandstones along 15km of an east-west striking structure. Uranium mineralisation is associated with at least three carbonaceous horizons and several sandstone units, and has been known in the region since the early 1900’s. Historical geology reports of surface and subsurface sampling, plus recent drilling, suggest that there is potential for a near surface uranium resource.
