|
Frank Creek Prospect
Location
The Frank Creek prospect is 77 km northeast of Williams Lake, BC, the nearest major supply center. Basic supplies can also be obtained in Likely BC, which contains a small grocery store, gas station, motel, and restaurant. Access to the Frank Creek prospect from Likely is north via logging roads for 20km. Just before Keithley Creek a branch turns eastward and within 0.3 km crosses the Cariboo River. At the road junction just across the river, the left fork is at Km 0 of Weldwood's 8400 Road. This is followed northward for 3 or 5 km to the C- and D-Roads, respectively, which access the Frank Creek prospect. Each of these logging roads is well maintained; however, a few rough sections are the result of recent erosion and lack of maintenance. Because Weldwood is actively logging fir, spruce, and pine trees in the area, access and road maintenance are good.
Property History
Frank Creek, which is also known as Goose Creek, has seen sporadic placer mining, since the turn of the century. The Rasmussen brothers undertook the most recent placer activity from 1984 to 1986. During this placer mining, several massive sulphide boulders were uncovered during the sinking of a 15m shaft on the east side of Frank Creek. These contain up to 5% Zn+Pb and 2% Cu. A hard-rock mineral tenure named Home Run was staked, but little exploration was done and the property lapsed in 1987. This area was restaked in May, 1987, and subsequently became part of the Mass claim group in February, 1988. In 1988, Formosa Resources Corporation optioned the Mass claim group and did grid-soil-sampling, VLF-EM geophysical surveys, and limited geological mapping. This study identified several coincident geophysical and soil geochemical anomalies, which Formosa geologists believed to be the result of a VMS system.
During 1988, Formosa Resources Corp. and Rio Algom Mines conducted grid-controlled soil sampling, VLF-EM geophysical surveys and limited geological mapping. As a result of this work, they identified several coincident geophysical and soil geochemical anomalies. A trench excavated on a coincident Cu-Zn-Ag soil anomaly encountered rusty soil and lenses of ferricrete containing pyrite-rich fragments that contain also minor chalcopyrite, galena and sphalerite. On the slope above the above-mentioned alluvial massive sulphide boulders, 22.4 km of grid lines were cut and soil sampling was conducted at 25-m intervals, yielding some anomalous Cu, Pb, Zn and Ag concentrations, but no outcropping bedrock mineralization.
During 1991, helicopter-facilitated magnetic, electromagnetic (EM) and radiometric surveys by Rio Algom identified seven areas containing anomalous EM signatures in the Frank Creek area, F-1 to F-7 target areas and recommended follow-up programs.
During 1996, two, vertical, percussion holes were drilled along the D-Road switchback near the center of the F-1 target area by R. Yorston, a previous operator. They yielded poor recovery, mainly of very fine particles and minor amounts of rock chips of black and green phyllite. Both holes returned anomalous Cu, Pb, Zn, Ag and Au concentrations in the upper 18.3 m, with the best interval being 3.04 m averaging 1770 ppm Cu, 750 ppm Pb, 2970 ppm Zn, 4.8 ppm Ag and 790 ppb Au.
Barker Completes Frank Creek Staking
Barker has been aware of the potential for VMS deposits in the Frank Creek area since 1994 and has been aquiring mineral claims in the Frank creek and surrounding area since 1996 when the prospective ground became available for staking.
In June of 1999 Barker Minerals staked a strategic property called the "Frank" claim near the mouth of Frank Creek in the area of the massive sulphide boulders previously found by placer miners, and which also encompasses significant airborne Mag/EM geophysical and Cu, Pb, Zn, Ag soil geochemical anomalies. An immediate study and evaluation program was planned and commenced upon the snow melting, making the property accessible.
Purpose of Study
The objective of this 1999 study was to identify the volcanological, alteration, and mineralization characteristics, which could help locate favourable stratigraphy that could host VMS mineralization similar to the massive sulphide boulders near the mouth of Frank Creek. When a zone of massive sulphide boulders was found, part of the focus of the study was concentrated on exploring this zone.
Summary of Work Done
In the central part of the Frank Creek area, previously identified outcrops were examined and sampled, with a goal of determining whether the lithogeochemistry of the area supported an environment that might contain a VMS deposit. When numerous pyrite-rich samples were discovered near an old trench that contained abundant ferricrete, part of the study became focussed on exploring this zone. This examination near the trench and above a road-drainage culvert 150m east of the trench uncovered many more boulders of massive sulphide and stringer-style sulphide mineralization. This includes many cobbles and boulders that had been oxidized and weathered into pure oxide minerals and could not be removed intact from the overburden. One layer in the overburden appears to be enriched in massive sulphide boulders. The full extent of this layer is not known, and prospecting is continuing.
Frank Creek - VMS Discovery
Prospecting by Louis and Jim Doyle, in the Frank Creek area in June 1999 revealed a massive sulphide boulder zone. This was the first reported discovery of economic grade massive sulphide mineralization in the area of airborne geophysical and geochemical anomalies found in previous exploration programs. Massive sulphide boulders assayed up to 15 % Pb, 3.5 % Zn, 1.3% Cu, 20 ounces per ton Ag and .6 grams per ton Au.
Follow up detailed prospecting and hand-trenching to a depth of two metres in the overburden uncovered an even higher concentration of massive sulphide boulders. Noting that the boulders were increasingly angular, large and fresh, we recognized that we were close to the source. Preliminary prospecting with a GSM-19 VLF-Magnetometer near the massive sulphide boulders indicated a nearby conductor. Once the orientation was determined, a trench across the zone was proposed.
This trench has led to a very significant discovery which is the first volcanogenic massive sulphide discovery ever made in the Barkerville terrane. The dimensions of this massive sulphide zone are unknown at this time, however a minimum width of 1.4 metres is exposed at surface.
Frank Creek VMS showing
During 1999, a trench excavated in a zone of weathered massive sulphide boulders near a culvert 2.2 km up the "D" logging road of the Frank Creek project area (project area #4) exposed a stratiform, massive sulphide layer at least 1.2 m thick over a strike-length of 10 m. The attitude of the layer (strike 167º, dip 32º) is subparallel to that of the major foliation (S2) in the surrounding rocks. Additional boulders containing massive sulphide and stringer-style sulphide mineralization were found along strike as far as 150 m away. Reconnaissance VLF and Mag geophysical prospecting indicated the potential presence of a conductor under the D Road. Assay results of grab and chip samples collected from the boulders and outcrop suggest zoned-type, massive sulphide mineralization. The volume and grade of the mineralization have yet to be determined. During 2000, one chip sample was collected from a pod of magnetic massive sulphide 25 cm thick located stratigraphically beneath the main massive sulphide layer.
The massive sulphide samples collected from the Frank Creek showing and placer boulders found approximately 1.3 km downstream present a wide variation in composition, potentially reflecting the possible presence of a strongly zoned deposit. Such variation is typical of many VMS deposits in the world. Most notable are those samples containing concentrations of Ag greater than 14 oz/t and Pb concentrations ranging between 8 and 15.4%. These also contain Cu concentrations in the 0.3-0.6% range and Zn concentrations in the 1-5% range, and some are anomalous in As (1000-8000 ppm), Sb (300-600 ppm), Bi (55-285 ppm) and Se (50-195 ppm). Samples of the placer boulders are similar but contain much lower concentrations of Ag (2-4 oz/t) and Pb (1.9-4.5%), and containing anomalous Sn (300-500 ppm) and concentrations of Zn up to 5.4% and Ba up to 3% (Formosa 1989). Two massive sulphide samples and two from the stringer zone are rich in Cu (1.7-7.4%); these contain 0.5% Zn and minor Pb and Ag. One grab sample collected from the massive sulphide outcrop by an independent mining company contains 8.2% Zn. Many samples are anomalous in Au (200-450 ppb).
Major Mining Company Comments:
"High grade assays from the Frank Creek property visits and Barker Minerals' exploration results from the Ace and other prospects underscore the significant untapped exploration potential of the Likely area. Furthermore, we are encouraged by the variety and widespread distribution of base and precious metal mineralization over the entire property package."
December, 1999
Several samples contain 10-25% CO3 as calcite and dolomite; this is probably secondary in mafic rocks, but may be, in part at least, primary in phyllite and shale. Carbonate is not abundant in the felsic lapilli tuff, quartz monzonite, or quartzite. Phosphate is very abundant in two samples that are intermediate between shale and phyllite. The Ti/Zr ratios for quartzite, felsic lapilli tuff and quartz monzonite are low, relatively uniform and similar. Those of phyllite and shale are moderately higher and more variable. Mafic rocks have very high and fairly uniform ratios of Ti/Zr, which are high mainly because of a very high Ti content. Barium and potassium are unusually high in the mafic rocks in comparison with normal mafic rocks; this may be the result of potassic metasomatism.
Another point of interest was that large fresh, angular blocks of massive sulphides were pulled from the trench's first six metres. As this area was below the water table, it was not known if bedrock was reached or not?
Prospecting also led to the discovery of a block of massive sulphides .3m x .5m, which was 50 metres west of a strong airborne target and 110 metres east of the massive sulphides exposed in the trench. This discovery, along with anomalous polymetallic soil and stream signatures in the Frank Creek area, leads us to believe that other airborne targets may also be caused by VMS mineralization.
A mini grid was completed over the Frank Creek discovery area in December to test soil geochemical and geophysical techniques for follow-up programs. The result was a confirmation of the VMS horizon through a VLF geophysical survey, the soil survey also outlined a strong anomaly of Cu, Pb, Zn & Ag that correlates well with the VLF anomalies.
This survey also outlined a much stronger parallel conductor 50 metres west of the exposed massive sulphides in the trench. This may represent another lens of massive sulphide mineralization. Results of this study confirm that soil geochem and VLF-EM/Maxmin surveys should be reliable tools in future programs to trace the VMS horizons.
Detailed ground geophysics, prospecting and geological mapping over all of the airborne conductors is planned, to be followed by trench and drill programs.
SCR Project
Surface geological mapping of an area of about 9 km2 encompassing the Frank Creek and SCR project areas was conducted by Dr. Payne. The centre of the Frank Creek project area had been mapped during 1999. Geological mapping conducted during 2000 was outwards from the initially mapped area.
Thirty-five rock samples were collected and analyzed from the Frank Creek and SCR properties. Petrographic examination was performed on 27 rock samples and 7 massive sulphide samples collected from outcrops, most of which were collected within the Frank Creek project area.
Aggregate lengths of grid line cut in 2000 were: 88 km at Frank Creek Project and 17.9 km at the SCR Project. Magnetometer readings over the entirety of both grids were recorded at 25 m intervals on lines spaced 100 m apart. On the Frank Creek grid, 39.5 km of HLEM geophysical surveying were completed and 19.9 km were completed on the SCR grid. The HLEM survey was conducted on portions of the grids by using a dipole separation of 100 m on the Frank Creek grid, with local areas of detailed survey conducted at 50-m spacing on lines spaced 100 m apart. The HLEM survey on the SCR project was conducted using a dipole separation of 200 m. The locations of base lines and other key locations were determined by GPS surveying.
The magnetic contrast on the Frank Creek grid is low. Despite this, the magnetic patterns mimic the bedrock geology in some areas. Intermediate to volcanic rocks have moderately higher magnetic susceptibilities than the black argillite and siliceous siltstone unit.
The HLEM survey defined several poor to moderate HLEM indicated conductors in the Frank Creek area. Most are shallow and dip steeply. Indicated conductors A and B trend northwesterly east of the massive sulphide outcrop and are located stratigraphically just above the prominent quartzite-limestone marker that is exposed in Frank Creek canyon. The presence of Cu-rich stringer sulphide outcrops stratigraphically above the massive sulphide outcrop suggests the possibility of stacked massive sulphide deposits and makes the indicated Conductor A an excellent target for exploration for a massive sulphide deposit. Indicated Conductor C is broad, trends northwesterly and appears to dip shallowly to the east. Indicated Conductor D dips steeply. Indicated Conductors E, F, G, J and K are associated with the black argillite-siliceous siltstone unit below the intermediate volcanic rocks. Indicated Conductors A, B, C, D, E, F, G, J and K are associated with intense, coincident Cu-Pb-Zn soil anomalies.
Indicated Conductors H and I are anomalies that occur near the Big Gulp showing (F-4 target area) and are open to the west in an area containing no outcrop. One group of HLEM anomalies is associated with a stratigraphic unit of black argillite and quartz siltstone located structurally just below the volcanic rocks. Another, with a coincident soil base-metal anomaly, is in the altered volcanic rocks slightly higher on the ridge. Some of these anomalies are open at one or both ends. More work will be required to define them more completely.
SCR Discovery
During 2000, prospecting by Barker Minerals personnel resulted in the discovery of the SCR semi-massive sulfide occurrence located 4 km west of the Frank Creek Project.
A significant, new VMS prospect has been identified with the discovery of semi-massive sulphide and stringer sulphide mineralization in float and bedrock of altered intermediate to mafic volcanic rocks of the Sellers Creek Road area. Sulphide minerals include pyrite, pyrrhotite, chalcopyrite, sphalerite and galena. The geophysical surveys successfully outlined significant, coincident magnetic and conductive anomalies (HLEM) near the discovery area and near the area of Cu, Pb and Zn soil anomalies. The presence of volcanogenic massive sulphides at the Ace, Frank Creek and SCR properties shows that potential exists for VMS deposits across the entire width of the Barkerville terrane.
In the SCR grid area, the magnetic contrast is 3.5 times higher than in the Frank Creek grid area, with a relief of 700 nanoteslas. A 300-m-wide mag high that trends northwest correlates with the south side of a rib of Quesnel Lake gneiss. A narrower mag high trends in the same direction further to the south. Two moderate HLEM indicated conductors trend across the grid in the same orientation as the magnetic anomalies and one (Conductor A) is coincident with Cu/Pb/Zn soil anomalies. Indicated Conductor A is narrow, presents poor to good conductivity and is associated with a strong magnetic feature. Indicated Conductor B is a narrow anomaly of poor to moderate conductivity paralleling indicated Conductor A, located to the southwest.
From the SCR property, fifteen rock samples were collected from surface outcrops and boulders of semi-massive sulphide. Many of these are silicified intermediate volcanic rocks, some of which contain disseminated to semi-massive sulphides dominated by pyrite. A few samples carried anomalous concentrations of one or more of Cu, Zn and Pb, while a few carried anomalous concentrations of one or more of Co, Bi, Se and Sn. Samples SCR-7 and SCR-7a carried anomalous concentrations of Pb and Zn, but contain only minor concentrations of pyrite.
The Frank Creek area contains an important massive sulphide occurrence situated near the stratigraphic top of a fragmental, felsic volcanic rocks or feldspathic arkose. This overlies, in order, a section of black argillite and siltstone and an intermediate to mafic volcanic sequence of flows and fine fragmental rocks. Associated with the massive sulphide zone is a Cu-rich zone of stringer and replacement mineralization. The stratigraphic section is on the overturned limb of one of a set of major, southwesterly verging, F2 folds. All the rocks are metamorphosed, which has inhibited interpretation. The discovery of pillow structures in mafic volcanic rocks in Frank Creek indicates a sea-floor subaqueous environment, thereby enhancing the potential for further discoveries of massive sulphide deposits in this belt of rocks. The association of the Frank Creek massive sulphide and the Ace massive and stringer sulphide mineralization to volcanic rocks enhances the potential for discovery of additional VMS mineralization not only the Goose Range, but throughout the entire Barkerville terrane.
The massive sulphide outcrop, spatially related boulders and the Cu-rich stringer and replacement zone contain anomalous to potentially economic concentrations of Cu, Pb, Zn and Ag. Many samples are anomalous in Au and some contain anomalous concentrations of As, Bi, Cd, Hg, Sb, Tl and Mo. Concentrations of As, Bi, Hg, Mo and Sb also are anomalous in stream-sediment samples near other airborne geophysical anomalies. The HLEM survey suggests the presence of another massive sulphide target stratigraphically a few tens of metres above the massive sulphide outcrop.
The Big Gulp showing (F-4 Target) contains anomalous concentrations of Zn in strongly altered intermediate to mafic volcaniclastic rocks associated with a series of east-west-trending HLEM anomalies. This may be indicative of a stringer zone associated with a massive sulphide deposit.
The discovery of the massive sulfide zone and its probable genetic relationship to the felsic volcanic rocks indicates that this area has potential for an economic VMS deposit. Although the felsic rocks are different from those at the Ace VMS showing to the northeast, the proximity of two such zones in the Barkerville terrane enhances the potential of discovery of more VMS deposits in the belt.
Frank Creek and SCR Project Areas Geology
Work by Struik (1983) and Ferri (2001) placed the rocks of these project areas in the Snowshoe Group of the Barkerville terrane. These rocks include, from oldest to youngest, the Keithley succession, Harvey's Ridge succession and Goose Peak quartzite. The Keithley succession consists of micaceous quartz sandstone to siltstone, phyllite and quartz-muscovite schist, in which common pyrite and ankerite porphyroblasts give a brown to rusty brown weathering surface. At the top of the Keithley succession is a distinctive quartzite. Southwest of Browntop Mountain, a section of rusty-weathering quartz-chlorite-muscovite schist of the Keithley succession contains two stratabound intervals of marble 50-75 m thick. This area also contains a quartzite unit that is less than a few metres thick and contains minor disseminated chalcopyrite, sphalerite and galena. The upper contact of the Keithley orthoquartzite is sharp with the dark grey to black siliceous siltstone and phyllite of the Harvey's Ridge succession.
The lower part of the Harvey's Ridge succession is characterized by dark grey to black phyllite, schist, siltstone, siliceous siltstone and sandstone. An important wedge of mafic volcanic rocks occurs west of the Frank Creek fault. The upper contact of the Harvey's Ridge succession is gradational with the overlying Goose Peak quartzite. The contact is placed at the base of the lowermost, thick section of clean, feldspathic sandstone to quartzite. The Harvey's Ridge succession contains abundant interlayers of coarse grained, feldspathic sandstone and wacke, similar to but darker in colour than those of the Goose Peak quartzite.
The Goose Peak quartzite contains micaceous and feldspathic sandstone to quartzite, with minor interlayers of grey to dark grey phyllite/schist, siltstone, wacke and quartz-chlorite-muscovite schist (possibly of volcanic origin). This unit caps many of the higher ridges situated to the east of the Frank Creek fault, including Goose Peak, Badger Peak and Borland Mountain. The Agnes conglomerate occurs in the upper transitional portion of the Harvey's Ridge section and may be a lateral equivalent of the Goose Peak quartzite. The Quesnel Lake gneiss, which intruded the older rocks in the Frank Creek area, was dated at 357.21.0 Ma by the U-Pb zircon method by the BC Geological Survey (Ferri, Hoy and Friedman, 1998).
The stratigraphic section is overturned and warped by a series of broad late-stage (F3) folds. Most rocks are variably slaty, foliated, laminated or schistose. In much of the Frank Creek area, the main foliation (S2) dips moderately to the west or southwest, in contrast to the regional trend of moderate dips to the northeast, such as at the Ace project area. The Frank Creek area is in the nose of a series of broad F3 folds that warp S2 gently to steeply, locally, and plunge gently to the northwest.
Most rocks of the Frank Creek project area are of the Harvey's Ridge succession. At the stratigraphic base of the section (top of Frank Ridge) is a finely banded, tuffaceous, basaltic andesite. Much less abundant are massive, coarser grained flows, one of which contains a few pillow flows, whose orientation supports the overturned model. A transition zone contains intercalations of volcanic and sedimentary rocks and mixed rocks described as tuffaceous phyllite. Stratigraphically overlying this unit (downslope to the north) is a zone of mixed quartz-pebble and sugary quartz sandstone, dark grey to black quartz siltstone and black argillite. Further downslope is a unit at least several tens of metres thick containing abundant angular fragments of quartz and lesser plagioclase ranging 0.5 - 3 mm in size. This unit has been interpreted either as pebbly sandstone to conglomerate or medium to coarse felsic tuff. It contains intervals up to a few metres thick of black, argillaceous schist that is mainly non-graphitic, but contains local zones of significant graphite content.
A broad interval represented by little to no outcrop separates the main zone of quartz-pebble rocks from the stratigraphic level of the massive sulphide. Stratigraphically above the massive sulphide showing is a small outcrop containing abundant zones of pyrite and chalcopyrite replacement and stringer mineralization. The discovery of the massive sulphide zone and its probable genetic relationship to these rocks, which have been interpreted by Payne and some others to be felsic volcanic rocks, indicate that this area has potential for an economic VMS mineral deposit.
Major Mining Company Comments:
"We commend you for the highly professional manner in which you have carried out your exploration and compiled the resulting data," and "The property clearly has potential to host a VMS deposit, and Barker Minerals has systematically and methodically advanced the project."
December 19, 2000
Further to the east and northeast is a resistant marker unit of quartzite and locally finely laminated limestone. The interpretation of this unit is not resolved. If the section is overturned, as detailed data suggest, this could be part of the Goose Peak quartzite. Alternately, it might be an interval of the Agnes conglomerate. In some outcrops, a pseudo-conglomeratic texture was produced by deformation. Some of these outcrops contain scattered, rounded boulders up to 25 cm across of quartzite of the same composition as the matrix. If they are actual boulders, the rock would be a true conglomerate. The limestone is exposed only in the canyon of Frank Creek. The quartzite continues as a significant stratigraphic marker unit to the southwest, where it does not contain any pseudo-conglomeratic textures.
To the east, a major fault (Frank Creek fault) identified in this study, drops the Frank Creek block down with respect to the Goose Peak block to the east, in which surface rocks are dominantly Goose Peak quartzite. Although regionally, F3 folds and L12/L23 lineations in the Goose Peak block also plunge gently to moderately to the northwest, within about 1 km of the Frank Creek fault, the plunge is reversed to gently to the southeast. Further work on the regional folding should be done in order to resolve the facing direction of the stratigraphic section and the direction of movement on the Frank Creek fault. Preliminary work in this study suggests that the stratigraphic section is overturned and the fault is normal.
Frank Creek Exploration Plans
Geological mapping will continue in order to help determine the stratigraphic and structural setting of the mineralization. This will be integrated with that being done by Ferri of the B.C. Geological Survey between the Ace and Frank Creek areas.
The HLEM survey will be continued in areas of the grids not covered during 2000, especially to trace continuations of known anomalies that are suggestive of the presence of massive sulphide deposits. Preliminary gravity survey lines will be run across the main anomalies to more accurately define massive sulphide targets. Where topography and glacial cover are permissive, trenches will be excavated into prospective targets resultant from these studies.
The most prospective anomalies as defined by geology, geophysics, geochemistry and trenching will be tested by diamond drilling.
SCR Exploration Plans
Geological mapping will continue in order to help determine the stratigraphic and structural setting of the mineralization. This will be integrated with that being done by Ferri of the B.C. Geological Survey between the Ace and Frank Creek areas.
The HLEM survey will be continued to the east and southeast of the present grid to determine the extent of the anomaly in those directions. Where permissive, trenching will be conducted on defined target areas.
Soil geochemistry may be conducted over the grid and would be extended to the east to cover the possible extensions of the anomalous zone as defined by geology and coincident magnetic and HLEM anomalies.
Diamond drilling will test the most prospective anomalies as defined by the geology, geophysics, geochemistry and trenching.
|
