Abstract The aim of this field trip is to illustrate the geological setting and controls on gold mineralization in the Cadillac-Bousquet mining district, the major gold producing district in the Quebec Abitibi belt (Fig.1). The development of auriferous system in this area are invariably associated with major tectonic features in the volcano-sedimentary pile. The regional tour will focus on the dominant structural and stratigraphic features of the various lithological units and on the structural controls of gold mineralization. The underground tour and surface visits will allow participants to become acquainted with the complex geology of an area, that hosts several types of gold mineralization. To date, approximately 79,800 kg of gold have been extracted from over 11 orebodies on the Doyon, Bousquet and Dumagami properties (Marquis, 1990). Proven and probable gold reserves for the district are estimated to be more than 230 tonnes of gold at an average grade of 5,1 grams per tonne (Marquis, 1990).

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.