Field Trip Report Essay
Field Trip Report
Excursion at the Montauban mine (September 21st, 2014)
Montauban is a Zn-rich VMS deposit that has been exploited from 1910 to the 1960s including several gold-rich zones. The deposit is hosted in highly deformed volcanic rocks metamorphosed to the upper amphibolite grade. Part of the deposit is observable on outcrops and a section from the altered footwall to unaltered basalts in the hanging wall has been visited by a group of six student from the Université Laval and the INRS-ETE. Antoine Caté, Ph.D. student on a metamorphosed VMS deposit lead the tour. Students have observed a typical section through a tilted VMS deposit with the unusual mineral assemblages due to the high-grade metamorphism (anthophyllite, grossular, tremolite, sillimanite, calcsilcates…), as well as porphyroblastic sulphides (sphalerite and pyrite). The field trip allowed students to observe the effect of metamorphism on hydrothermal alteration mineral assemblages and to document the geometry of a VMS deposit.
Figure 1: Students of the chapter on the Montauban les Mines site.
Visit of COREM installations in Quebec City (Friday January 17, 2014) A group of 4 students went to visit the COREM installations, which is a research consortium for mineral treatment and metallurgy techniques. The visit was leaded by Jean-François Wilhelmy, Extractive Mineralogy Researcher, to learn about different physical and chemical methods used in the industry. The group visited the pilot factory, which demonstrates several of these processes. The students were also introduced to the MLA (Mineral Liberation Analyser), a new device that can precisely and rapidly quantify minerals in concentrate samples.
Visit of Niobec Mine in Saint-Honoré (Wednesday March 19th, 2014) The visit was leaded by Marc Lavoie, Geology Technician, and Jean-François Dorion, Exploration Geologist. The 10 students had the chance to hear a speech about the local geology and the mining processes used in Niobec. The group also visited the underground installations and had a view of the ore body, and then made a stop at the core shack. Finally, the geologists took some time to explain to the students how the niobium is extracted from the muck, and what processes it implies to do so. This visit also allowed several students to go in an underground mine for the first time and was very appreciated by the group.
Field trip in the Thetford Mine area (April 26-27, 2014)
A two day field trip in the Thetford Mine area guided by Stéphane de Souza, post-doctoral fellow at the Geological Survey of Canada has been organized. Seven students participated. The aim of the field trip was to do a cross section through the Appalachian orogen, to document the ophiolitic sequence at Thetford Mine and to observe the mineral occurences associated with these environments. During the first day, students have observed and interpreted many structural features, including the overprinting of several deformation events and a shear-hosted vein network similar to that close-by orogenic gold occurrences. A visit of the Saint Joseph asbestos quarry has also been completed. Asbestos had a major influence on the economy of the area until recently and huge waste piles are still visible around the city of Thetford Mine.
Figure 2: Stéphane De Souza explains the complex structural setting of the Appalachian orogen.
During the second day, outcrops illustrating the geology of the obducted Thetford Mine ophiolite sequence have been visited, as well as a syn-orogenic conglomerate that contains deformed clasts and that is overlaind by thick cherts. A podiform chromite showing located in an altered harzburgite and an old stratiform chromite mine have been visited.
This field trip allowed the students to observe the geological setting of various mineral ressources and to discover the prospectivity of the Appalachian orogen.
Figure 3: chrysotyle veins and podiform chromite in an harzburgite. Snow is still present in the cold canadian spring.