Translation of original French
|Author:||Geoffroy and Koulomzine, 1948, 1960|
|Type area:||NTS sheet 32C05|
|Geological province:||Superior Province|
|Geological subdivision:||Abitibi Subprovince|
The Mogador Pluton was first recognized and described during geophysical and drilling campaigns of grouped companies Celta Dev & Mining Co Ltd., Vendome Mines Ltd., Roymont Mines Ltd. and Mogador Mines Ltd. (Geoffroy and Koulomzine, 1948, 1960; Geoffroy, 1949, 1953; Koulomzine, 1951). It was later named « Mogador Granodioritic Batholith » (Geoffroy, 1953). As part of their mapping of the Fiedmont and Barraute townships, Brown (1958) renamed this intrusion “Mogador stock”, while McDougall (1965) called it “Mogador plug”. Beullac (1983) then re-used the name “Mogador stock”. Finally, the name « Mogador Pluton » was formally proposed by Pilote et al. (2019).
The Mogador Pluton is an intrusive mass whose composition varies from quartz monzonite to granodiorite. It is covered by >30 m of overburden and does not outcrop. Its extent and composition were determined by geophysical methods and several drilling campaigns. Based on its shape and position, the Mogador Pluton appears to be partially conformable with host rocks. Drill cores indicate that the mass margins are composed of quartz and feldspar, as well as considerable amounts of hornblende and interstitial chlorite. Quartz grains are opaline blue. Feldspar, whose composition is close to oligoclase, is usually altered. Ferromagnesian minerals are commonly chloritized (Geoffroy and Koulomzine, 1960). The pluton also contains marginal phases of dioritic, gabbroic and amphibolitic composition. Mafic dykes cut the pluton and were recognized in drilling (Geoffroy and Koulomzine, 1960). Some of the drilling that intercepted the Mogador Pluton yielded low gold values associated with quartz veins (Geoffroy and Koulomzine, 1948, 1960; Geoffroy, 1949, 1953; Koulomzine, 1951).
Available drill cores (88-17 and 89-14; D’Amours et al., 1988; D’Amours et de Corta, 1989) held by Mines Abcourt Inc. helped define the composition of the Mogador Pluton. It consists of lithologies ranging from quartz monzonite to granodiorite. These lithologies are granular and are characterized by the absence of foliation, except at the edge of the most important shears, where the rock is chloritized and epidotized. There is an aureole of amphibolite facies contact metamorphism that affects host volcanics over several tens of metres. Amphibolitized enclaves are commonly encountered in all drills that intercept this intrusion.
Thickness and Distribution
The Mogador Pluton forms an elongated disc in a WNW-ESE direction. It is estimated to be 4 km long and ~850 m wide. The pluton is associated with a large negative aeromagnetic anomaly observed on both ground (Geoffroy, 1953) and airborne (Geological Survey of Canada et al., 2009) geophysical surveys. The Mogador Pluton is crossed by the road leading to Mont-Vidéo (Mont-Vidéo Road), in sheet 32C05.
The Mogador Pluton cuts volcanic units of the Lanaudière Formation and is cut by Proterozoic diabase dykes. Granodiorite reminds of La Corne Batholith unit nAlac3 by its composition and calc-alkaline geochemistry. This suggests that the Mogador Pluton be of late tectonic age.
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Publications available through Sigéom Examine
BEULLAC, R. 1983. Région de Barraute-Fiedmont. Ministère des Richesses naturelles, Québec; DP-84-02DP-84-02, 1 plan.
BROWN, W G. 1958. RAPPORT PRELIMINAIRE SUR LE QUART NORD-EST DU CANTON DE FIEDMONT, DISTRICT ELECTORAL D’ABITIBI-EST. MRN. RP 364, 30 pages and 1 plan.
D’AMOURS, C., De CORTA, H. 1989. CAMPAGNE DE FORAGE (PRINTEMPS 1989), PROPRIETE BARDOME, BLOC VENDOME. MINES ABCOURT INC. Assessment work submitted to the Government of Québec. GM 49866GM 49866, 147 pages and 1 plan. Disponible à https://gq.mines.gouv.qc.ca/documents/EXAMINE/GM49866.
D’AMOURS, C., De CHAVIGNY, P., LACOSTE, P. 1988. MINERAGRAPHIE DE L’OR DANS SEIZE ECHANTILLONS DE PYRITE AURIFERE. MINES ABCOURT INC. Assessment work submitted to the Government of Québec. GM 48119GM 48119, 222 pages and 1 plan. Disponible à https://gq.mines.gouv.qc.ca/documents/EXAMINE/GM48119.
GEOFFROY, P R. 1949. DIAMOND DRILL LOG (MOGADOR MINES LTD). Assessment work submitted to the Government of Québec. GM 00550, 25 pages and 2 plans.
GEOFFROY, P R. 1953. Results of the magnetic survey (Celta Dev & Mining Co Ltd, Vendome Mines Ltd, Roymont Mines Ltd, Mogador Mines Ltd). Assessment work submitted to the Government of Québec. GM 02251GM 02251, 2 pages and 1 plan.
Disponible à https://gq.mines.gouv.qc.ca/documents/EXAMINE/GM022
GEOFFROY, P R., KOULOMZINE, T. 1948. REPORT ON A MAGNETOMETER SURVEY (MOGADOR MINES LTD, BARMONT MINES LTD). Assessment work submitted to the Government of Québec. GM 08226, 9 pages and 1 plan.
GEOLOGICAL SURVEY OF CANADA, NORANDA EXPLORATION, MINES D’OR VIRGINIA. 2009. Cartes géophysiques couleurs Megatem – 32C05. Ministère des Ressources naturelles et de la Faune, Québec; DP 2008-06DP 2008-06, 5 pages and 4 plans.
KOULOMZINE, T. 1951. NOTE ON THE LAST DRILLING RESULTS (MOGADOR MINES LTD). Assessment work submitted to the Government of Québec. GM 32303, 2 pages and 6 plans.
McDOUGALL, D. J. 1965. Quart sud-est du canton de Barraute, comté d’Abitibi-Est. Ministère des Ressources Naturelles du Québec; RG 114RG 114, 37 pages and 1 plan.
GEOFFROY, P.R., KOULOMZINE, T. 1960. Mogador sulphide deposit (Vendome Mines Limited). Canadian Institute of Mining and Metallurgy Bulletin; volume 53, pages 268-274.