The Quatsino Formation is a limestone sequence 60 to 250 metres thick that occupies a belt 3 kilometres wide extending northwest from Gillies Bay to Blubber Bay at the tip of Texada Island. It conformably overlies Karmutsen Formation volcanics and mainly comprises pure, massive to poorly bedded calcareous and dolomitic limestone. Both formations form part of the Upper Triassic Vancouver Group. Exposed contacts between the limestone and underlying volcanic rocks are usually marked by steep faults. The volcanic rocks comprise rhythmically layered amygdaloidal, feldspar porphyritic and spherulitic basalt flows. A major episode of folding (F1) has been recognized; this resulted in the limestones and, to a lesser degree, the underlying volcanics, being deformed into a series of broad, northwest trending open folds that plunge northwards. Two subparallel, northwest striking lineaments are evident in the area. The Ideal and Holly faults have apparently controlled the emplacement of some Jurassic intrusions and the associated skarn mineralization.

The Middle Jurassic Gillies stock intrudes both the Quatsino and Karmutsen formations. The stock has yielded a zircon U-Pb radiometric age of 178 Ma (Fieldwork 1989) and is genetically associated with several magnetite-rich skarn deposits (Prescott, Lake 092F 259, Yellow Kid 092F 258 and Paxton 092F 107) in an area 1524 by 609 metres. It mainly comprises a grey, medium-grained equigranular quartz monzonite that contains amphibole, biotite and occasional pyroxene phenocrysts. A late potassium feldspar rich phase is also present. The stock and the surrounding limestones are cut by sets of north and east trending feldspar porphyritic dykes that reach 10 metres in thickness and postdate skarn mineralization. The Gillies stock and its associated iron-skarn deposits lie close to the Ideal fault. Locally, at the iron mines (Prescott, Lake, Yellow Kid and Paxton), the volcanic-limestone contact is highly deformed and these structures have partly controlled the distribution of the magnetite ore. The Karmutsen volcanics in the vicinity of the Gillies stock are variably metamorphosed, most generally to a chloritized or epidotized basalt; the Quatsino limestone is bleached white and coarsely recrystallized.

Magnetite skarn mineralization at the Prescott mine is generally developed close to or along the margin of the Gillies stock and comprises an irregular lens or group of lenses that plunges steeply south, parallel to the dip direction of the quartz monzonite-limestone contact. Mineralization is concentrated along either the Quatsino-Karmutsen formations contact, the margin of the Gillies stock or within limestone and volcanic rocks some distance from the stock where the skarn forming fluids were controlled by subvertical brittle fractures. Magnetite orebodies adjacent to the stock are generally associated with abundant garnet-pyroxene-amphibole skarn, while the more distal, structurally controlled, subvertical deposits have less extensive skarn envelopes. The massive magnetite occurs with reddish-brown garnet, pyroxene (hedenbergite-diopside), epidote, amphibole (actinolite), minor calcite and sporadic chalcopyrite, pyrite and pyrrhotite. Traces of arsenopyrite and rare sphalerite are also observed (International Geological Congress Guidebook, Day 2-Texada, by A. Sutherland Brown). The skarn alteration and mineralization overprints all phases of the Gillies stock and, to a lesser degree, the limestone and volcanic rocks, although it is difficult to distinguish between exoskarn and endoskarn. Contacts between the skarn and unaltered rocks are generally sharp. Mineralogical zoning is recognized and, where fully developed, comprises barren skarn close to the intrusion, grading outwards to magnetite-rich skarn and then into marble. Locally, chalcopyrite and pyrite occur close to the outer margins of the skarn envelope, adjacent to limestone or marble. Magnetite veinlets commonly cut garnet-pyroxene skarn. Early garnet-pyroxene assemblages were followed by the introduction of magnetite and late sulphide mineralization. Feldspar porphyry dykes are prominent in the magnetite orebodies.

Copper concentrates produced from milling contain recoverable amounts of gold and silver. The initial discoveries of the four main iron-skarn deposits were from west to east, the Prescott, Yellow Kid (092F 258), Paxton (092F 107) and Lake (092F 259). Subsequent discoveries by underground exploration included the Midway (combined with the Yellow Kid), Le Roi (combined with the Yellow Kid), Lake Extension (combined with the Lake) and Anomaly A (combined with the Prescott). During the years 1885 to 1903, and 1908, 26,213 tonnes of magnetite ore were reported to be shipped; this was from the Prescott deposit except for approximately 964 tonnes from the Lake deposit (092F 259). Sporadic activity continued until 1916; at that time the workings at the Prescott mine included a large quarry, shaft, an adit connected to the shaft and four working levels above the adit. No further activity was reported until 1952 when open pit operations began in earnest at the Lake, Paxton and Prescott deposits.

Production figures from the Lake (092F 259) and Paxton (092F 107) mines are included with the Prescott. The Yellow Kid deposit (092F 258) was discovered in 1953-54; in 1955 an open pit operation started and in 1957 milling of magnetite ore began. Underground exploration began in 1959 in an adit driven from the shoreline to explore beneath the Prescott and Yellow Kid open pits. In the course of this underground development, the Midway deposit was discovered between the Prescott and Yellow Kid pits and production from here, beginning in 1964, is included with the Yellow Kid. A shaft and 5 levels were established to mine the deposits. A crosscut driven in 1964 to intersect the Lake Extension orebody (an extension of the Lake deposit), discovered another orebody, the Le Roi, which occurs between the Paxton open pit and the Yellow Kid open pit. The Le Roi orebody, due to its proximity to the Yellow Kid deposit, has been included with the Yellow Kid. A decline was started in 1966 from the Lake open pit to mine the Le Roi and Lake Extension orebodies. By 1968, all open pit mining ceased. Some underground development work was done on the Anomaly A orebody in 1969-70, located 440 metres northwest of the Prescott open pit.

Reported production from 1952 to 1956 totalled 1,300,466,116 kilograms of iron from 1,997,313 tonnes mined.

The Texada Mines, which encompassed all of the above deposits and orebodies, closed on December 17, 1976 due to exhaustion of ore reserves. Recent sampling of skarn mineralization at the mines assayed 3.14 per cent copper, 46.62 grams per tonne silver and 2.81 grams per tonne gold across 5 metres (George Cross Newsletter #217, 1988).

The property is held by Consolidated Van Anda Gold Ltd.