Abstract The Val d’Or mining district, located in the southern part of the Abitibi belt in the Superior Province, consists of a typical Archean supracrustal volcanosedimentary sequence, obliquely cut by narrow northeast-trending Proterozoi’c diabase dykes. The geology of the Val d’Or area is shown in figure 1. It was initially described by Gunning and Ambrose (1940) and Norman (1946, 1947), and was subsequently revised by Latulippe (1976), Imreh (1984) and more recently by Robert (1989). The northernmost volcanic unit in the Val d’Or area is an extensive ultramafic lava plain known as the Malartic Group. The Lower Malartic is mainly composed of komatiitic ultramafic lava and subordinate basaltic flows. The Upper Malartic, comprised of basaltic lava with horizons of ultramafic and felsic volcaniclastic rocks (lmreh, 1984), is dominated by two main schistosities, S 1 and S 2 S 1 , oriented northwest, is related to the principal flattening plane. S1 is reoriented by an east-west fabric (S2) which is related to asymmetrical Z-folds found over most of the Val d’Or area. The Kiena Mine, one of the mines we will visit during the second day of our tour, is hosted by the Upper Malartic Group. The Kewagama Group, located to the south of the Malartic Group, contains beds of metawacke and metapelite which have undergone two distinct folding events.axial planes related to the first folding event, oriented northwest, have been reoriented during a second phase of deformation that generated folds whose axial traces are oriented at 278 ° (Tourigny, 1984). The Blake River Group, dominating the Rouyn-Noranda district 100 km to the west of Val d’Or, pinches out between the metasedimentary Kewagama and Cadillac groups near the town of Malartic. Here, the Blake River Group is composed of brecciated basaltic lavas with a main schistosity oriented at 275 ° . The Cadillac Group, occurring to the south of the Blake River and Kewagama groups, is composed of metawacke and metapelite. Axial plane traces oriented at 284 ° terminate against the contact of the Blake River Group. The Piché Group is found only within the Cadillac tectonic zone in the Val d’Or area. It consists mainly of ultramafic lava. Where the deformation is intense, the lava is completely transformed to talc-carbonate schist. Where the deformation is less intense, spinifex textures are still visible. The Cadillac tectonic zone, generally oriented east-west, has been traced from Vauquelin township (east of Val d’Or) west to the border of Ontario and beyond.

Abstract This excursion is mainly based on work done by the field trip leader between 1976 and 1977 in the framework of an M.Sc. thesis supervised by Léopold Gélinas and Jean Lajoie at l'Université de Montréal. By that time, the association of massive sulphides and rhyolites was already well documented in the Rouyn-Noranda district. A large portion of the rhyolites were thought to be flows. However in more recent environments, such as Japan, rhyolitic volcanism is mostly explosive especially near mineralized areas. This association can be explained by the porous nature of pyroclastic breccias that facilitates the circulation of hydrothermal fluids necessary for the formation of volcanogenic deposits. The eas i 1 y access i b 1 e Don Camp 1 ex crops, put over 90 % of the area and provides a unique opportunity to observe and study volcanic processes that could not otherwise be fully appreciated under normal outcrop conditions or with drill hole data.

Abstract The Bousquet m1n1ng district (the Doyon, Bousquet and Dumagami Mines) is located in the southern part of the Abitibi greenstone belt of Quebec, 55 km east of Rouyn-Noranda (see index map on Fig.1). Eight lenticular auriferous pyrite bands have been delineated on the Bousquet property (Fig.2); they are either associated with mafic and felsic volcaniclastic rocks (zones 1, 2, 3, 3.1, 4, 4.1 and 5) or mafic lava flows intercalated with sericite schists and felsic tuffs (zone 6) (Valliant, 1981). Three zones are presently in production {1, 3 and 5) and two others (3.1 and 4) are at the mine development stage. Since 1979, three million tons of ore grading 0,2 oz Aujt have been produced and reserves are estimated to be over thirteen million tons. The gold mineralization and the pyrite lenses are intimately associated with the highly strained segments of the Blake River volcanic rock pile of this area. In the southern part of the group, the stratigraphic relationship among the various lithologies are obliterated or obscured and a penetrative tectonic fabric prevails throughout. The objectives of this excursion on the Bousquet property are to examine the geological setting of these gold-bearing pyrite lenses and look at some of the brittle and ductile structures that have been mapped on the property by the first author during the summers of 1984 and 1985.