The Chapais-Chibougamau region is located in the Superieur Province that is part of the greenstone orogene of Matagami-Chibougamau. The Archean rocks of the region are part of two distinct groups: the Roy Group, consisting mainly of volcanics; and the Opémisca Group, which is detritic-volcanic. The Opémisca Group is in discordant contact with the Roy Group. The rocks of the region are metamorphosed in the green schist facies, with the amphibole facies occurring in the proximity of some of the intrusions. The Roy Group, consists of five formations defining two volcanic cycles going from felsic to mafic, which are from the bottom to the top: The Obatogamau formation, the Waconichi formation, the Gilman formation, the Blondeau formation and the Bordeleau formation.
Structurally the regional deformation has formed isoclinal folds with an East-West orientation that is associated with the regional foliation. The deformation is also responsible for the formation of the larger structures of domes and basins in the region. From North to South the following structures are found: the Waconichi syncline, the Waconichi anticline, the Chibougamau syncline, the Chibougamau anticline, the Chapais syncline, the Dauversière anticline and the Druillettes syncline.
The Fancamp, Diana-Obatogamau and Dolbo properties are located in between the Muscocho plutons in the west, the Verneuil plutons in the south and the La Dauversière plutons in the east. The first is a post-tectonic intrusion with a dioritic to tonalitic composition while the last two are syntectonic intrusions with a granodioritic composition.
The properties of the Chevrier project cover for the main part the Fancamp fault that has a NE/SW orientation and is sub-parallel to the stratigraphy. On the Diana property, a fault with an orientation of N50°E displaces the lithologies with an apparent right-hand movement.
Economically, the region presents a number of gold anomalies that are predominantly situated near the Northeast and north-northeast faults, and especially along the Fancamp fault, where the Chevrier zone, the Lipsett showing and the B Zone of Murgor (on which property a ramp has been excavated) are located. The Lac Meston mine (also known as Joe Mann Mine) is also located in the proximity of a north-northeast fault. The area offers also a potential for massive volcanic sulfide deposits associated with the Waconichi Formation.
The underlying rocks of the Fancamp, Diana-Obatogamau and Haufan properties constitute principally of basalt's, massive concordant and discordant gabbros and of felsic to intermediate pyroclastites. Felsic dykes with quartz and feldspar phénocrystals cut these units. A granodiorite intrusion out-crops in the extreme Southwest of the property. Being part of the deformation corridor of the Fancamp fault, the region has been affected by at least four phases of deformation.
The properties can be divided into three distinct zones based on their structural characterization. The WEST zone shows a foliation of 240° and a stratigraphy varying between 030° and 010°. The CENTRAL zone is characterized by a general NE orientation of the units and the schistosity. This zone corresponds with the deformation corridor of the Fancamp fault. Finally, The SOUTH zone is characterized by a general EW foliation and by a higher magnetic signature. |