Project Description and Location
The South Lone Mountain property is located about 32km northwest of the Eureka Nevada in central Nevada. Bravo owns 52 unpatented mining claims, approximately 939 hectares, located on U.S. federal land managed by the Battle Mountain BLM office. The claims are distributed as several small blocks of claims located in T.20N., R.50E., S. 10, 11, 14, 15; T.20N., R.51E., S. 7, 8, 17 and 18; T.21N., R.50E. S. 7, 16, 21, 23, 24, 25 and T.21N. R.53E. sections 27, 28, 33, 34. The claims are legally registered and recorded with both the BLM and Eureka County. Bravo has paid $16,240 to the BLM and must pay $10.50 per claim to Eureka County by November 1st to hold the claims through September 1, 2011. The Nevada Legislature recently passed an additional one-time fee on unpatented claims held in the state of Nevada. Pending legal challenges, the Company will be required to pay an additional $85.00 per claim to Eureka County by June 1, 2011.
Many of the claims were staked by Placer Dome as part of a property agreement with Bravo. Placer contributed money to drill nine reverse-circulation and mud-rotary holes on the property. Placer was purchased by Barrick and the agreement was terminated so that Bravo now has a 100% interest in the property. No further payments or royalty interests are due to Placer or Barrick. A 1% NSR royalty would be payable to Trend, if the property were to produce. One half of this (0.5%) can be purchased for US$3,000,000.
All disturbance activities that were done while the Bravo/Placer Dome property agreement was in effect are the responsibility of Placer Dome. Bravo submitted a Notice which was accepted by the BLM to cover drilling that it did in late 2006-2007 after the agreement with Placer Dome was terminated. The BLM has closed the Notice and accepted reclamation as complete. The total amount of the bond posted by Bravo has been released and the Notice has been closed. At this time, Bravo does not plan any drilling in the near future on the property. If Bravo elects to drill at a future date, a Notice would have to be filed with the BLM and an appropriate bond would need to be posted to cover reclamation work. No other environmental issues or liabilities are known on the project.
No know mineralized zones, mineral resources, mineral reserves, mine workings or mine waste piles exist on the property.
Accessibility, Climate, Local Resources, Infrastructure and Physiography
The property is accessed from Eureka by driving approximately 32km west on Highway 50 to an unimproved dirt road. From this intersection, a dirt road extends northward for about 9km to the property. An alternative route may be used during periods of muddy conditions. The alternative route utilizes the Roberts Creek Road, approximately 19km west of Eureka, from there one would travel approximately 8km north to a set of unimproved roads that provide access around the northern margin of Lone Mountain.
Drilling is best accomplished from about late April through November, but can be carried out in December and January if care is taken to move equipment when the ground is frozen. Work should be avoided from about February through late April due to very muddy conditions.
Water and power are available locally. Motels and restaurants of various types are available in Eureka. Should an economic discovery be made, necessary infrastructure, such as power, water, access, housing, etc., would also be available in Eureka, the county seat of Eureka County. Ample flat ground for a mine development is available in the vicinity, some controlled by Bravo’s claims. Vegetation is a mix of sagebrush and desert grasses. Water and Power are available relatively nearby, but would have to be procured should a mine be constructed. Supplies can be trucked to the site from Carlin, approximately 125km to the north. Carlin is on both the Interstate 80 highway and a rail line and is a center for logistics for the many large mines of the Carlin trend.
Nothing is known about the exploration history of the property prior to the location of the claims that Bravo controls. No previous drilling or is known to have taken place on the property. Bravo controls all interests in the claims that it controls.
Most of the property is covered by gravel, but hints to the bedrock geology are present on the east flank of the project and the adjacent area of Lone Mountain. Several relatively deep holes in the basin also have defined the geology.
The South Lone Mountain project is on the northwest-trending Battle Mountain-Eureka gold trend. The basin to the west of Lone Mountain has been downthrown at least 300m from the bedrock exposures on Lone Mountain. Seismic evidence and drilling suggests a series of Northeast-trending normal faults the cut the basin. Several northwest trending faults are also indicated by the seismic work. Most of the drill holes in the basin have encountered at least 300m of gravel cover.
A continuous, gently northeast-dipping stratigraphic section from Cambrian through upper Devonian age is exposed at the property.
Devils Gate Limestone - The Devils Gate Limestone (Devonian) is composed of medium-to massive-bedded gray limestone. It is not regarded as a favorable host rock for gold deposits, except where extensive cave and karst features are well developed near gold-bearing structures, such as occurs at Newmont’s Rain Deposit. Such environments may exist on South Lone Mountain, but are not known. The thickness of the unit at Lone Mountain is more than 335m, but the top is not exposed.
Denay Limestone - The Devonian Denay Limestone underlies the Devils Gate Limestone and overlies the McColley Canyon Formation. It is mapped by Bravo on Lone Mountain as about 240m thick. On Lone Mountain, the unit is variably dolomitic and composed of light gray to brown dolomite and dolomitic limestone. To the south of Lone Mountain, the unit is more strongly dolomitized and probably more correctly described as the Simonson, a dolomite unit. To the north of Lone Mountain, the Denay is described as having a lower and an upper unit. The lower unit is composed of thin-to medium-bedded, limy mudstone and calcarenites and the upper unit is composed of medium-bedded, limey mudstone in the upper portion and thin siliceous, calcareous mudstones in the lower portion. The upper Denay is a known host for gold at the Gold Bar deposit, but the dolomitic character at South Lone Mountain makes the unit’s ability to be a favorable gold host questionable.
McColley Canyon Formation - The McColley Canyon Formation (Devonian) is composed of three members that are, from oldest to youngest, the Kobeh, Bartine and Coils Creek members. The aggregate thickness of the units, as measured on Lone Mountain, is 260m and the individual thicknesses of the three members are 18m, 149m and 93m, respectively. To the north of the South Lone Mountain property, in the Gold Bar District, the overall thickness of the unit is somewhat less, but still substantial.
The Kobeh member is composed of dolomite and cherty limestone, the Bartine is composed of thin-to medium-bedded, bioclastic limestone, and the Coils Creek is composed of medium-to thick-bedded, gray limestone. The Bartine member is the most favorable host rock within the McColley Canyon because a relatively thick portion of it, about 50m thick, is very-thin bedded and highly fossiliferous. Argillaceous partings and a calcareous content of this member provide a rock that is permeable and prone to shattering over substantial widths in and near structures.
Lone Mountain Dolomite - The Silurian Lone Mountain Dolomite stratigraphically underlies the McColley Formation and overlies the Roberts Mountain Formation. The Lone Mountain Dolomite is not considered a good host for gold, and may provide a cap for gold mineralization. Bravo’s mapping on Lone Mountain indicates a thickness of about 430m.
Roberts Mountain Formation - The Roberts Mountain Formation (Devonian-Silurian) is regarded as one of the most prospective host rocks for gold deposits in Nevada and has been encountered in several drill holes on the South Lone Mountain property. Generally, the Roberts Mountain Formation is a thin–bedded, silty limestone, but on Lone Mountain, and under the basin to the west, the unit is variably dolomitized. This character detracts somewhat from the favorability of the unit as a gold host but Bravo believes that enough of the unit has retained its thin-bedded calcareous character that it could still be favorable for gold deposition in the presence of a strong, gold-bearing hydrothermal system. The unit is estimated from Bravo mapping as 214m thick on Lone Mountain.
Hanson Creek Formation – The Hanson Creek Formation (Ordovician) is composed of medium-to thin–bedded, gray dolomite. Black chert is common near the top of the unit. It is estimated to be 78m thick on Lone Mountain. The Hanson Creek is not generally considered a favorable host rock for gold in this region.
Eureka Quartzite – The Eureka Quartzite (Ordovician) is composed of gray to white orthoquartzite on Lone Mountain. The basal portion is somewhat clay rich and has a dolomitic component.
Antelope Valley Limestone - The Antelope Valley Limestone is the oldest unit exposed on Lone Mountain and probably the oldest unit that would be encountered in any drilling that Bravo would contemplate on the property. The unit is composed of light-to medium-gray limestone, and some dolomite that may be thin bedded. The base of the unit is not exposed, but it attains a thickness of 335m about 40km south of the South Lone Mountain property.
Bravo (as operator) and Placer Dome (funding work to earn in) reported in February 2005 anomalous gold in samples collected from an oil well at the property. The chips contained up to 2.36g/t Au in basal gravel that included jasperoid fragments and jarosite-stained, decalcified siltstone and fine sandstone. One chip of material remaining in the un-assayed split was later observed to contain a vug lined with quartz crystals and euhedral barite. The basal gravel sits directly upon Roberts Mountains Formation, which has been dolomitized at this location and contains minor quartz veinlets. Gold up to +300ppb was obtained from bedrock samples immediately beneath the bedrock interface with younger gravel or volcanic cover. Anomalous samples from the bedrock may have been contaminated with gravel caved from above and it is uncertain if the gold is related to bedrock mineralization or gravel contamination.
Based on this evidence for a gold system in an important host rock along the Battle Mountain Gold trend, Placer staked a large claim block, which became part of the property agreement with Bravo. Bravo/Placer acquired additional geology and geochemistry from other historic oil wells in Kobeh Valley, conducted geologic mapping and sampling at Lone Mountain, collected detailed gravity geophysics over the entire property and some surrounding areas, purchased and reprocessed 48-linekilometers of seismic geophysics, collected soil and gas geochemistry, and drilled nine reverse-circulation and mud-rotary holes for a total of 3,514m in 2005 and early 2006. Two areas were tested by drilling. Bravo drilled three additional mud-rotary holes (1,247m) during late 2006/early 2007.
Surface samples were collected from the west slope of Lone Mountain where bedrock is exposed. Gold is weakly anomalous in the vast majority of samples. The maximum value received from assays was 0.15g/t Au. Arsenic is also anomalous in several samples; a maximum of 1,710ppm. Although anomalies were detected, the surface geochemistry was not used extensively in targeting drill holes because no strong alteration or structure was associated with the anomalous values.
Drilling was done both near the western flank of Lone Mountain and in the gravel-covered basin near the oil well with the anomalous gold. Several holes were completed in the vicinity of the oil well to test the Roberts Mountains Formation. Several analyses of fine and coarse fractions of the drill samples were conducted from a few holes near the oil well. The oil well cuttings were washed and sieved, and thus only the course fraction was available for analysis. The results of these analyses are discussed later in this section.
Mud-rotary drill hole PSLM0601 intersected a 12-meter interval beginning at 456 meters depth with low-level gold, up to a maximum of 65ppm Au, and anomalous pathfinder elements that are often associated with Carlin-type gold systems. Arsenic up to 239ppm, antimony up to 2.7ppm, and thallium up to 0.35ppm are distinctively elevated in the interval relative to background. Base metals are not anomalous. Bedrock was intersected at 427 meters and consists of dolomitized Roberts Mountains Formation with minor to common dolomite veinlets. Caving of overlying gravel was a significant problem in this particular hole, so the possibility cannot be ruled out that mineralized fragments within the gravel contributed gold to the interval; 62 meters of gravel immediately overlying bedrock was assayed every 1.5 meters and contains a maximum of 10ppb Au.
Hole PSLM0601 is located approximately 15 meters in a N40W direction from the oil well. Gravel immediately above bedrock in PSLM0601 contains minor chips of jasperoid and friable sandstone, but does not contain the same level of anomalous gold, indicating the distribution of gold at the bedrock contact is erratic.
Hole PSLM0505 was drilled approximately 168 meters east of the oil well and contains a maximum of 31ppb gold. The Roberts Mountains Formation and other bedrock formations are generally unaltered, with weakly anomalous pathfinder elements.
Hole PSLM0602 was located on a separate target, approximately 1.5km to the southeast of the oil well. It contains weakly anomalous gold, a maximum of 19ppb in Lone Mountain dolomite, and no anomalous gold in the Roberts Mountains Formation.
In contrast to the oil well, the basal gravel in holes PSLM0505 and PSLM0601 did not contain anomalous gold in the original samples submitted. To further investigate the nature of gold in the basal gravel, partially washed samples (left over material from which chip trays were made) were composited for the 15m interval immediately above bedrock in holes PSLM0505 and PSLM0601. Two 7.5m composite samples were made; one 0-7.5m above bedrock and one 7.5-15m above bedrock. The fine portion of the samples consists primarily of post-mineral volcanic ash and clay, while the coarser portion is primarily derived from pre-mineral Paleozoic bedrock. This selective sampling maximizes the chances of detecting the presence of gold, but it cannot be considered representative of the drill interval.
Approximately 1 kg of composited material was analyzed utilizing a metallic-screen assay by ALS Chemex. The sample is sieved after the entire 1 kg is crushed. Two splits of the -100 micron fine portion are assayed by normal 30-gram fire assay. Approximately 30 grams of +100 micron coarse fraction is present, and it is analyzed in its entirety as a separate fire assay. The assays are then combined on a weight percentage to yield a final assay for the interval. Metallic gold and resistant rocks such as jasperoid will usually concentrate in the coarse fraction.
In hole PSLM0601, which is closest to the oil well, the 7.5m sample immediately above bedrock contains 710ppb Au in the coarse fraction and the overlying 7.5m sample contains 340ppb Au in the coarse fraction. Assays of the fine fractions contain less than 50ppb Au, which is the detection limit. Because the coarse fraction is such a small percentage of the entire sample, the weight adjusted grade remains less than 50ppb Au. In hole PSLM0505, located 168m east of the oil well, gold is less than 50ppb in both the coarse and fine fractions.
The presence of gold in the coarse fraction is further evidence of a gold system nearby. Much higher values obtained from the oil well may indicate that the oil well hit a particularly rich mineralized boulder(s) or metallic gold entirely by chance, or that the oil well is closer to the source of the gold than either of the recent holes. There may have been enrichment due to washing out unmineralized material in the oil well chips; however, rotary drilling used in oil wells is generally a highly dilutive process due to contamination. Bravo estimates that roughly 90% of the oil well chips were unaltered in the 2.36g/t interval.
Evidence for a nearby source of the gold includes:
- One of the chips of jasperoid (possibly auriferous) from the oil well contains delicate crystals of hydrothermal barite that would not likely survive significant alluvial transport.
- Friable jarosite-stained siltstone/sandstone (possibly auriferous) would also not survive much alluvial transport. This decalcified siltstone and fine grained sandstone looks similar to the basal portion of the Hanson Creek Formation encountered deep in hole PSLM0505, where it was unaltered. With beds dipping to the east and the depth to bedrock increasing to the east, a western source is indicated.
- The presence of anomalous gold and pathfinders 30m below the bedrock contact in PSLM0601 suggests a nearby gold system.
- The nearest known gold deposit is Gold Bar, located approximately 16km to the northwest, where no alluvial gold has been identified. Three other oil wells that Bravo and Placer Dome sampled between South Lone Mountain and Gold Bar contained less than 18ppb Au immediately above bedrock, and no more than 40ppb Au in any alluvium.
Lone Mountain Pediment Area - Three holes successfully tested the Bartine member of the McColley Canyon formation on the northwestern margin of Lone Mountain, and two holes were lost in deeper-than-expected gravel. The holes contain no anomalous gold values in bedrock, but do contain up to 784ppm zinc, 4.2ppm mercury, 3.2ppm selenium, and 2,960ppm barium.
Zinc Mineralization - Other than the gold at the bedrock interfaces that is discussed in the above section, the Lone Mountain Property is adjacent to a historic lead-zinc producer that reportedly produced almost 5 million pounds of zinc and 650,000 pounds of lead through 1964.
Bravo examined information from three historic oil exploration holes that were drilled in the basin to the west of Lone Mountain. Logs were available for these holes and a limited amount of chips were available in small envelopes held by the Nevada Bureau of Mines. Bravo was allowed to sample a portion of the chips and to have them analyzed for gold and other elements.
A total of 13 holes have been completed on the South Lone Mountain property while Bravo has held an interest in the property. A total of 4,925m have been drilled. Both reverse circulation and mud-rotary methods have been utilized, and in the case of one hole, both methods were used. Generally, holes less than 300m deep were drilled with a reverse–circulation rig and holes more than 300m deep were drilled with a mud-rotary drill rig.
Results confirm the presence of strongly anomalous gold in the course fraction of drill samples near the bedrock interface in the oil well, but the source of the gold is still not known. The significant anomalies of gold are always near the bedrock interface, and the presence of significant gold in the bedrock is not known.
Sampling and Analysis
Bravo collected rock samples from the west flank of Lone Mountain near the eastern edge of the property where bedrock is exposed. Soil samples from fault scarps in the alluvium were taken from areas of the property covered by gravel. No set width or interval of sample density was used. The purpose of the surface-sampling program was to identify and confirm the presence and strength of gold anomalies, and to identify any geochemical zoning patterns. Only minor alteration was noted, and sampling was concentrated on those areas, but unaltered altered areas of the property were also sampled.
The rock samples collected at the surface by Bravo were analyzed by American Assay Labs and ALS Chemex, both ISO certified laboratories. Surface rock samples generally consisted of approximately 1 to 2.5kg of rock. The samples were crushed to 70% -10 mesh from which a 200-gram pulp (90% -150 mesh) was taken. A 30-gram digestion was analyzed by fire assay, followed by atomic absorption for gold, and a 0.5 gram split was digested for multi-element analysis by ICP. Bravo relied on blanks and standards utilized by the laboratory for quality control for their surface samples.
Drill samples were collected every 1.5m. Wet samples from the reverse circulation drilling were collected in a 5-gallon bucket lined with a cloth bag. The amount of sample that was diverted into the bag was controlled so that approximately 4 to 7kg of material was sampled. Wet duplicate samples were collected from effluent from the wet splitter that normally flowed onto the ground. Wet samples from mud rotary drilling were collected off of the mud screens in buckets. Duplicate samples were also collected every tenth sample from an adjacent location off of the mud screen.
No significant issues with the quality of the drill samples were noted during the program. Occasional limited circulation occurred, but was not a serious problem. Bravo utilized blanks and standards, as well as the duplicate samples, to monitor the quality of the analysis of the drill samples. A blank was always inserted as the first sample in every sample shipment and as the first sample of each drill hole. At least one gold-bearing standard was submitted for each drill hole. If the hole was deeper than 150m, then additional standards were submitted. No pervasive or serious issues with sample reproducibility were noted.
Security of Samples
Surface samples were collected by consulting geologists working for Bravo who controlled their collection, transportation and delivery to the laboratory. Bravo’s policy is to have a geologist monitor their drilling projects during most of the daylight hours when the drill rig is working. One of the responsibilities of the geologist is to have vigilance for any signs of tampering with the drill samples. No tampering was noted by the geologist or the drill crew. Bravo drill samples were allowed to remain on the ground by the drill rig for up to a few days, but never when the drill rig was unattended during the day. The drill sites were at a remote location near the end of a seldom used dirt road. Samples were picked up by a truck sent by the laboratory. In some cases, such as the delivery of the duplicate samples, samples were delivered to the laboratory by the geologist. In general, the drill crew was always on site as drilling occurred 24 hours per day and samples were picked up prior to drill breaks.
Mineral Resource and Mineral Reserve Estimates
No mineral resources or mineral reserve estimates are known or have been made on the South Lone Mountain Property.
No mining operations are active on the property.
Exploration and Development
Bravo plans no drilling on the property in the near future. Although no bedrock gold mineralization has been encountered, the source of the gold in the gravel has not been discovered; thus, several blocks of claims are held in areas that are believed to remain prospective. The lead-zinc potential is also worthy of monitoring. Bravo will seek a joint-venture partner and monitor competitor activity to help determine its future exploration plans on the property.