Preliminary Map 67 displays generalized geology and outcrop distribution in the central volcanic axis of the Quesnel terrane in the Quesnel Lake and Quesnel River areas near the village of Likely (NTS 93A/12) at 1:50 000 scale.
Mapping covers about 600-square kilometres and extends from south of latitude 52 degrees, 30 minutes to about latitude 52 degrees, 45 minutes and between longitudes 121 degrees, 30 minutes and 122 degrees, 0 minutes, small portions of adjoining map sheets 93A/5, 6, 11 and 92B/9 are also included.
The mapping updates and extends Preliminary Map 20, 1976, Geology of the Morehead Lake Area. It emphasizes the continuity of Triassic-Jurassic and some younger stratigraphic units in the volcanic arc axis, outlines volcanic-intrusive centres, and identifies faults that are southern extensions of the Pinchi fault system.
Mesozoic volcanic rocks in the map-area exhibit a bi-symmetric, generally regular distribution. Norian fine-grained epiclastic sediments comprise the basal strata of the Mesozoic assemblage. Upward. Mafic volcanism produced variably pillowed basalt flows and polylithic breccias, then mafic siltstone and limestone; local alkalic units occur. Above these are Sinemurian polylithic breccias, latite tuff and breccia, feldspathic sandstones and analcite-bearing alkalic basalts. These rocks in turn are overlain by Pleinsbachian interbedded sandstone and siltstone and chert-bearing polylithic conglomerate with sandstone and shale interlayers.
Areas of Pliocene olivine plateau basalt occur locally.
Intrusive rocks include Pleinsbachian syenite to monzodiorite and Cretaceous nepheline syenite and quartz monzonite to granodiorite.
Alkalic stocks elsewhere in the belt host porphyry copper-gold deposits and are highly prospective. This mapping, which is north of Quesnel River, covers the main area of current exploration interest near the Quesnel River (QR) propylitic basalt-hosted gold deposit. Calc-alkalic intrusions have potential to host copper-molybdenum porphyry deposits.