The Vault developed prospect is located 500 metres west of Highway 97 along Skaha Lake, 4 kilometres northwest of Okanagan Falls, British Columbia.
Quartz veining and an associated gossan were observed by B.N. Church of the British Columbia Geological Survey Branch. The Vault 1 claim was subsequently staked in 1982 by M. Morrison. Riocanex Inc. optioned the property and staked the Vault 2-5 claims. In 1983, Riocanex Inc. drilled the Discovery zone and subsequently dropped their option. Dome Mines Ltd. acquired an option, conducted further property exploration, then also allowed their option to lapse. In 1985, Seven Mile High Resources Inc. optioned the property conducting further exploration. A drill program was completed, consisting of 24,505 metres in 72 holes. In 1989, the company name was changed to Seven Mile High Group Inc. Inco Gold earned a 60 per cent interest in the property.
The Vault occurrence lies within the eastern part of the White Lake basin, a thick accumulation of Eocene Penticton Group volcanic rocks, interlayered with clastic sedimentary rocks which are largely of volcanic derivation. The Eocene rocks rest unconformably on Triassic metavolcanic and metasedimentary rocks of the Independence, Old Tom and Shoemaker formations, and Jurassic granitic intrusions. The White Lake basin forms a topographic low and is truncated by early gravity faults. The units generally dip to the east and are folded and faulted.
The stratigraphic sequence on the Vault property includes the Kitley Lake Member at the base, overlain by the Marama Formation, with the White Lake Formation at the top. The rocks are gently folded about northeasterly trending synclinal and anticlinal axes and offset by northerly and northeasterly trending faults which form a step-like downdropped pattern. Precious metal mineralization is related to an east-west oriented fracture system confined largely to the lower Marama Formation.
The Kitley Lake Member consists of purplish brown to grey, fine grained, plagioclase porphyritic lavas of trachyte to trachyandesite composition. The upper contact of this unit is strongly weathered.
The overlying Marama Formation is the favourable host unit in which gold-silver mineralization occurs, and is subdivided into upper and lower sections. At the base of the lower Marama is a coarse pyroclastic and/or epiclastic unit. The section grades upward into a crudely alternating sequence of coarse and fine grained, tuffaceous and fragmental rocks, believed to reflect repeated explosive events. Much of this section varies from lapilli to ash tuff, with coarse fragments and massive fine grained, trachyte porphyry flows intercalated with thin laminated mudstone and siltstone. The flows display abundant, irregular clay and zeolite(?)-filled amygdules. In some areas the tuff is broken into larger subrounded clasts that are probably the result of epiclastic processes. At other localities the breccia has a random chaotic appearance, characteristic of laharic slumping or debris flow.
The upper Marama is a massive, aphanitic dacite flow unit that is plagioclase porphyritic, with alkali feldspar, minor hornblende and biotite. Some outcrops display flow banding and platy brittle fracture. Sheeted dacite feeder dikes, averaging about 1 metre in width, intrude the dacite in the central part of the property.
At the top of the Vault sequence the White Lake Formation consists of coarse agglomeratic and laharic rocks interlayered with andesitic and trachytic flows, conglomerates and carbonaceous mudstones.
Drill information indicates that alteration is dominated by an elongate zone of intense silicification and stockwork veining occurring above the Kitley Lake Member/lower Marama Formation contact. In drill core, the intensity of silicification appears to increase with the frequency of quartz veining. Within the area of mineralization, silicification is pervasive and the replacement of wallrock by chalcedonic quartz is locally evident. Clay alteration is common adjacent to fault zones and is particularly notable as feldspar alteration in trachytic flows and breccias. Minor muscovite and green micaceous minerals are also present in altered sections. Hematite, calcite and chlorite alteration are poorly developed in all units and are usually confined to fractures, vein margins and breccia matrix or fragments. Calcite veinlets usually crosscut silicic alteration and veining.
Gold-silver mineralization is associated with a discontinuous, east trending, steeply dipping quartz vein system on the north limb of a northeast-trending syncline. Veining is concentrated primarily in lower Marama rocks, where the porosity and permeability of the volcanic breccias and tuffs are highest, although a few minor gold-bearing veins have been encountered in the Kitley Lake and upper Marama formations. Intense silicification and weak, very fine grained pyritization accompanies much of the mineralization.
Near-surface mineralization, where silicification is less intense, is generally anomalous in precious metals, but below an estimated economic grade of less than 3 grams per tonne gold. With increased depth, silicification becomes more intense and the average grade increases to the 5-10 grams per tonne range, in places over substantial widths. Gold and silver are typically not visible to the naked eye, but are considered likely to occur as native elements, or possibly as electrum. Silver-gold ratios in the mineralized zones are highly variable, averaging 9.8:1. The ratios tend to be lowest with higher gold values.
Veins in the main mineralized zone have typical adularia- sericite-type epithermal textures and mineral assemblages. Finely banded and bladed chalcedonic quartz, ankeritic carbonate and minor alkali feldspar (adularia) are the main vein components. Veins range in size from fine irregular anastomosing veinlets a few millimetres thick, to larger veins about 10 centimetres wide. Some exceptionally large veins are up to about 30 centimetres in width. They commonly display multistage growth textures, such as scalloped colloform banding, bladed cockscomb intergrowths and drusy cavities. Where the vein minerals occur as breccia matrix, some breccia fragments are rimmed with finely banded quartz and occur in a matrix of black, grey and white silica. Some of the most significant gold values are associated with complex multistage veining. In a number of intersections the veins have been brecciated and subsequently rehealed by the addition of banded silica. In other areas, banded quartz clasts are a significant component of the breccia.
The sulphide content associated with mineralization is typically low, although some sections are highly oxidized, with 5 to 10 per cent pyrite which is very fine grained and may occur as disseminations, fracture or vein-breccia fillings and thin veinlets. Minor pyrrhotite with sphalerite intergrowths is also associated with pyrite. Native gold is observed associated with pyrrhotite.
On a regional and vein scale, mineralization is structurally controlled by major northeast and east-trending faults and related parallel fracture systems. It is, in part, lithologically controlled, confined primarily to tuffaceous, agglomeratic and brecciated rocks of the lower Marama Formation (Exploration in British Columbia 1988, pages B5-B13).
Fluid inclusion and stable isotope studies at the Vault occurrence indicate epithermal fluids were responsible for mineralization events. The fluids are characterized by homogenization temperatures of 143 to 347 degrees Celsius, salinities of 0 to 3.4 weight per cent NaCl and oxygen del 18 values of minus 0.2 to 6.6 per mil (relative to standard mean ocean water). The mineralization occurred at depths of 3 to 4 kilometres. Early stage homogenization temperatures indicate the deposit likely formed around 270 degrees Celsius. Calculated oxygen-18 isotope values suggest three types of fluids were involved with mineralization formation at the Vault occurrence.
The Main zone is 600 metres long, 40 to 125 metres wide and 5 to 30 metres thick. The top of the mineralization is 170 metres below surface at the west end and 500 metres below surface at the east end.
The North Vein is a discrete narrow quartz-calcite-adularia vein located 350 metres north of the Main zone. Diamond drilling to date gives an indicated reserve on the North Vein of 152,000 tonnes of 14 grams per tonne gold on a vein approximately 1066 metres long and tested to a depth of 100 to 200 metres (George Cross News Letter #182, 1990).
Drilling by Seven Mile High Resources Inc. outlined an area 2.95 by 1.64 kilometres of epithermal gold mineralization.
In 1998, Winslow Gold Corp. acquired an option from Aqua Regia Mineral to earn 51% interest in the Vault property by completing $300,000 exploration, over 4 years.
The Vault property was explored and drilled by Inco between 1982 and 1990. Inco sold the property to Aqua Regia in May 1997.
In 2003, Ecstall Mining Corp optioned the Vault property from Aqua Regia Mineral Inc. The North vein has an indicated resource of 152 000 tonnes grading 14 grams per tonne gold. The Main zone is reported to have a resource of 1.55 million tonnes at 2.49 grams per tonne gold (Exploration and Mining in BC 2003, page 57). Ecstall is compiling and reinterpreting the large property data set.
In 2004, Ecstall drilled western end of the Vault Main zone encountering good gold values at shallow depths, such as 9 metres grading 2 grams per tonne gold (Exploration and Mining in BC 2004, page 59).
In 2005, only limited sampling was carried out by Ecstall on the property.