Khyber Pass is in the Bronson Corridor in northwestern British Columbia, approximately 95 kilometres northwest of Stewart. Khyber Pass is located 7.5 kilometres southeast of the past producing Johnny Mountain mine (MINFILE 104B 138) and 12.5 kilometres southeast of the past producing Snip mine (104B 250). Two kilometres north of Khyber Pass is the Inel developed prospect (MINFILE 104B 113).
The area is underlain by stratified rocks comprised of submarine to sub-aerial fragmental volcanic rocks that are interlayered with sequences of argillite, banded siltstone, greywacke, conglomerate and minor limestone. These rocks are thought to be correlative with Upper Triassic Stuhini Group, or in part the Lower Jurassic Hazelton Group.
These stratified rocks have been intruded by sub-volcanic and plutonic rocks that range from the Upper Mesozoic to Cenozoic times and are part of the Coast Plutonic Complex. The sequence is regionally metamorphosed to greenschist facies with the intrusion of a diverse suite of intrusive rocks. The altered intermediate to felsic pyroclastics and tuffaceous sedimentary rocks host widespread sulphide mineralization with pyrite and lead-zinc-copper sulphide veins and disseminations with some containing anomalous gold and silver values.
The controlling structural feature in the area of Khyber Pass is the Sky Fault System, a system of significant normal and reverse structures that extends from Pins Ridge in the southeast, through Sericite Ridge to Khyber Pass to the northwest. At Khyber Pass, the Khyber fault truncates the northeast-trending southeast-dipping Boundary-Billygoat fault, divides Khyber Pass from the Inel prospect, and appears to have exerted control on intrusion and mineralization (Fieldwork 2015-1).
The Khyber Pass zone on the Gossan 11 claim originally consisted of a northeast trending talus geochemical anomaly which was about 600 metres long and 150 metres wide. In 1985, rock chip sampling and trenching over this zone defined three main zones, the "A" zone, which comprises a copper-gold zone, the "B" zone which comprises an arsenic- rich zone, and the "C" zone which hosts high zinc and silver values. Drillhole 85-3, within zone "A", returned significant gold, silver and copper values over its 78-metre length. One sample over 5.2 metres assayed 5.8 grams per tonne gold, 91.2 grams per tonne silver and 0.9 per cent copper. Another sample from this drill hole, over 5.6 metres, assayed 4.11 grams per tonne gold, 222.1 grams per tonne silver and 1.74 per cent copper, respectively (Assessment Report 14055).
The stratified bedrock in the property has been divided into three; the lower banded siltstones and tuffs, middle andesitic pyroclastics, and an upper sedimentary sequence. Considerable alteration is apparent with pervasive secondary biotite and a large zone of intense pyrite-sericite alteration superimposed on the banded siltstones and tuffaceous rocks. The sericite-pyrite zone terminates abruptly against the overlying andesitic volcanics.
South of the Khyber Pass zone, in an area of considerable silicification and quartz veining, which appears to be related to a potassium feldspar, quartz-rich porphyry intrusive, chlorite, epidote and carbonate alteration is widespread (refer to Pyramid Saddle, 104B 323 and Pyramid Hill, 104B 207).
Sphalerite occurs as disseminations in some of the andesitic volcaniclastics where it is associated with chlorite-carbonate alteration. Diamond drilling in 1987 in the Khyber Pass zone has intersected sections of massive pyrite with lesser quartz, chalcopyrite, sphalerite and sparse galena, calcite and chlorite. Minor amounts of molybdenite, arsenopyrite and hydrozincite have also been reported. The mineralization occurs within the volcaniclastics and the underlying altered sediments. Assay results from the drill core have been reported as 4.1 to 148.4 grams per tonne silver and between 4.1 to 7.9 grams per tonne gold. Copper assays range from 0.05 to 1.61 per cent zinc values range from 0.21 to 1.42 per cent (Petersen, 1987).
The most significant control on mineralization within the KSP map area is the spatial relationship of large brittle-ductile strain zones. Two of the most important of these deformation zones are the Sky-Khyber Deformation Zone (SKDZ) and the Big Rock – Inel Deformation Zone (BRIDZ or BRDZ). These deformational zones have protracted deformational histories, are characterized by marked lithologic discontinuities and have a strong spatial relationship to the development of rock alteration and gold – copper mineralization.
Within the Inel-Khyber area, the SKDZ is a planar deformation zone which strikes approximately 140 degrees and has a strike length of over 25 kilometres. The trace of the fault is strongly affected by topography and it appears to have a shallow to 40-degree southwest dip. Kinematic indicators strongly imply that the most recent movements on the Khyber fault are dextral and reverse. The presence of numerous mineralized intrusive bodies which track the position of the SKDZ may indicate that at the time of mineralization, this structural zone was under active extension. The SDZ has a strike length exceeding 25 kilometres.
In 2017, three drill holes (INDDH17-093,094,095) were completed in the main Khyber area by Colorado Resources from one location. Previous drilling by Colorado in 2014 in the area was highlighted by KSP14-003 which yielded 2.98 grams per tonne gold over 34 metres including 18.1 grams per tonne gold over 2.4 metres. KBDDH17-093 was drilled approximately 400 metres to the northeast of this hole and yielded 1.87 grams per tonne gold over 20.4 metres from 32.0 to 52.4 metres including 2 metres of 9.39 grams per tonne gold from 38 to 40 metres with the drill hole ending in 20.4 metres of 0.72 gram per tonne gold including the last 5 metres of 1.43 grams per tonne gold from 121 to 126 metres (Colorado Resources Ltd., News Release, November 6, 2017). KBDDH17-094 drilled vertically from this same location failed to return significant results. KBDDH17-095 was drilled northwesterly from the same location and returned 1 metre of 1.69 grams per tonne gold from 147 to 148 metres (Colorado Resources Ltd., News Release, November 6, 2017).
Geological mapping and modeling for Colorado in 2017 conclusively demonstrated that much of the mineralization in the Khyber Pass (A Zone and Zinc Hill areas) as well as much of the mineralization in the Inel Discovery Zone is associated with a generally very flat lying surface which places a mafic fragmental unit discordantly against thin bedded sediments. This surface may be a regional scale thrust, a regional scale unconformity or a listric fault surface. The first interpretation may be the most probable as it is likely that portions of this rock mass have been deformed in north plunging synform-antiform couples defining a west verging fold and thrust belt.
In 1982, Chris Graf staked the Gossan 1-24 claims in 1982. He later optioned the Gossan 1-17 and 21-24 claims (328 units) to Lonestar Resources Ltd., who conducted an exploration programme on the claims in 1983 that consisted of geochemical sampling, geological mapping, and prospecting. The entire property was examined on a reconnaissance level by systematic stream silt, soil, and heavy mineral sampling, along each slope above lateral moraine level and along most ridge crests. Subsequently, grid soil sampling was conducted over areas of intense alteration, mineral occurrences and areas in which reconnaissance sampling had indicated anomalous precious-metal content. This programme delineated four areas which were anomalous in precious metals, the Khyber Pass, Wolverine, Pyramid and Lake zones.
Geological mapping to a scale of 1:10,000 defined a sequence of regionally altered intermediate to felsic pyroclastic volcanic rocks and tuffaceous sedimentary rocks intruded by a diverse suite of intrusive rocks Pyrite and Pb-Zn-Cu sulphide veins and disseminations were widespread but, generally, only a few contained interesting gold and silver values.
The area that emerged as being of most interest was the Khyber Pass zone on Gossan 11 claim where a northeast trending talus geochemical anomaly approximately 600 metres long and 150 metres wide contained values more than 1100 parts per billion gold. A line of continuous talus samples within the anomaly averaged 3.08 grams per tonne gold across 50 metres (Assessment Report 16727). In early 1985 Lonestar Resources relinquished their option on the property.
In mid-1985 Brinco Limited optioned the property and conducted detailed geological mapping, rock chip sampling and trenching over the Khyber Pass area. This work defined three main zones, the 'At zone, a copper-gold zone; the 'B' zone, an arsenic-rich zone; and the 'Ct zone, a zone with high zinc and silver values. These zones were tested by four short diamond drill holes of which one hole, 85-3, that tested the 'A' zone, yielded significant potentially economic gold, silver and copper values over its 78-metre length. The values were contained in several quartz-rich sulphide zones that were interpreted as being steeply dipping lodes.
In 1986 Brinco Limited conducted two small soil geochemical surveys in the South and the Northwest areas of the property. These surveys returned background results. Brinco Limited transferred the Gossan property to Western Canadian Mining Corporation in 1986. A total of 2,213 metres was drilled in seventeen diamond drill holes were drilled by Western Canadian in 1987. Two trenches, a South trench and a North trench, each approximately 50 metres long, were dug to bedrock using a backhoe. The diamond drilling has confirmed the A zone to contain Au, Ag, and Cu mineralization of economic interest. Sufficient mineralization was intersected in zones Band C to account for the geochemical gold anomalies, but the combinations of width and grade are insufficient to provide economic interest. One significant drill intersection assayed 3.4 grams per tonne gold, 9.43 grams per tonne silver, 0.34 per cent copper and 021 per cent zinc (Assessment Report 16727).
A limited program of blasting, trenching, and rock chip sampling was completed by Western Canadian in 1989. The ownership of the claims was transferred to Vector Industries International Inc. in February 1990. In 1990 Western Canadian, on behalf of Vector, completed an extensive program of geological mapping, soil sampling, rock sampling, induced polarization geophysical surveying, and diamond drilling. It was during this program that a new area was discovered by rock chip sampling, called the South Zone, and later renamed Khyber West (MINFILE 104B 685). Four holes were drilled in the A Zone, continuing to intersect precious and base metal mineralization. Three holes drilled at Zinc Hill intersected enriched zinc mineralization with moderate gold values (Assessment Report 35943).
SnipGold acquired the claims covering the area during the period 2007 through 2009 and in 2014 Colorado Resources Ltd. optioned the property from SnipGold. Colorado Resources conducted soil sampling, rock sampling, channel sampling, and drilling. The highest gold values from the rock sampling program came from coxcomb quartz veins or quartz-carbonate veins. Sample 2639681 returned 24.7 grams per tonne gold, 77.1 grams per tonne silver, and 0.7163 per cent copper. Three channel samples were cut, two of which did not return any significant results. Channel CH14-002 was cut into a chlorite-epidote altered intrusive rock with variable pyrite and magnetite. A 15-metre section of the 22-metre channel reported 0.76 gram per tonne gold and 0.594 per cent copper. Five drillholes (plus one at Khyber West) were drilled in 2014. Drillhole KSP14-003 reported 101.4 metres grading 1.16 grams per tonne gold, 3.13 grams per tonne silver, and 0.065 per cent copper. In the Zinc Hill area, drillhole KSP14-004 reported 9.05 metres grading 0.705 gram per tonne gold, 3.22 grams per tonne silver, 0.04 per cent copper, and 1.90 per cent zinc (Assessment Report 35184).
Limited prospecting and sampling were conducted at Khyber Pass by Colorado Resources in 2015. Rock sampling determined the area is enriched in molybdenum, reporting up to 4.18 per cent molybdenum. A small ground magnetometer geophysical survey was also completed (Assessment Report 35943).
In 2016, four short drill holes were completed at Khyber Pass to test a 500 by 1500 metre soil geochemical anomaly (greater than 500 parts per billion gold). Drill hole KBDDH1-01 reported 100 metres grading 0.14 per cent copper and 0.01 per cent molybdenum. The other drill holes reported anomalous levels of zinc (Colorado Resources Ltd. Press Release September 21, 2016).
In 2017, Colorado Resources completed a total of 11,824 metres of diamond drilling in 24 holes at the KSP property. Drilling tested the Inel-Khyber (104B 138) and Tami (104B 116) zones. Drilling on the Khyber Pass zone included 3 diamond drill holes and on the Khyber West (104B 665), 2 drill holes (Assessment Report 37604). Colorado Resources Ltd. announced its name change to QuestEx Gold & Copper Ltd. on Sept 16, 2020.