Temporal evolution and nature of Ti–Fe–P mineralization in the anorthosite–mangerite–charnockite–granite (AMCG) suites of the south-central Grenville Province, Saguenay – Lac St. Jean area, Quebec, Canada

2005 ◽  
Vol 42 (10) ◽  
pp. 1865-1880 ◽  
Author(s):  
Claude Hébert ◽  
Anne-Marie Cadieux ◽  
Otto van Breemen
Keyword(s):  
Temporal Evolution ◽  
Igneous Rocks ◽  
The South ◽  
Grenville Province ◽  
South Central ◽  
Titaniferous Magnetite ◽  
P Mineralization

In the south-central Grenville Province, Quebec, Canada, anorthosite–mangerite–charnockite–granite (AMCG) magmatism took place during four distinct episodes between 1327 and 1008 Ma. AMCG rocks crosscut several gneiss complexes composed of ~1506 Ma supracrustal rocks and massive to gneissic igneous rocks that were emplaced during two distinct episodes: ~1434 and 1393–1383 Ma. The four episodes of AMCG magmatism are (i) the 1327 ± 16 Ma labradorite-type De La Blache Mafic Plutonic Suite, (ii) the 1160–1135 Ma labradorite- and andesine-type Lac St. Jean Anorthositic Suite, (iii) a 1082–1045 Ma unnamed plutonic suite, and (iv) the 1020–1008 Ma andesine-type Valin Anorthositic Suite. The Valin Anorthositic Suite includes the 1016 ± 2 Ma andesine-type Mattawa Anorthosite, the 1010–1008 Ma andesine-type Labrieville Alkalic Anorthositic Massif, the 1020 ± 4 Ma St. Ambroise Pluton, the 1018+7–3 Ma Farmer Monzonite; the 1010 ± 2 Ma Gouin Charnockite, and the 1010 ± 3 Ma La Hache Monzonite. Study of the Ti–Te–P mineral occurrences in these four AMCG units in the south-central Grenville Province has shown that (i) apatite-bearing rocks are related only to andesine-type anorthosites, (ii) titaniferous magnetite is restricted to labradorite-type anorthosites, and (iii) hemo-ilmenite occurs only in andesine-type anorthosite and associated oxide–apatite-rich gabbronorites (OAGN) and nelsonites.

Mafic igneous rocks and mineralisation in the Palaeoproterozoic Ketilidian orogen, South-East Greenland: project SUPRASYD 1996

1997 ◽  
pp. 66-74
Author(s):  
Henrik Stendal ◽  
Wulf Mueller ◽  
Nicolai Birkedal ◽  
Esben I. Hansen ◽  
Claus Østergaard
Keyword(s):  
Mineral Exploration ◽  
Volcanic Rocks ◽  
Shear Zones ◽  
Field Work ◽  
Igneous Rocks ◽  
Border Zone ◽  
The South ◽  
East Greenland ◽  
North West ◽  
Arc Setting

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Stendal, H., Mueller, W., Birkedal, N., Hansen, E. I., & Østergaard, C. (1997). Mafic igneous rocks and mineralisation in the Palaeoproterozoic Ketilidian orogen, South-East Greenland: project SUPRASYD 1996. Geology of Greenland Survey Bulletin, 176, 66-74. https://doi.org/10.34194/ggub.v176.5064 _______________ The multidisciplinary SUPRASYD project (1992–96) focused on a regional investigation of the Palaeoproterozoic Ketilidian orogenic belt which crosses the southern tip of Greenland. Apart from a broad range of geological and structural studies (Nielsen et al., 1993; Garde & Schønwandt, 1994, 1995; Garde et al., 1997), the project included a mineral resource evaluation of the supracrustal sequences associated with the Ketilidian orogen (e.g. Mosher, 1995). The Ketilidian orogen of southern Greenland can be divided from north-west to south-east into: (1) a border zone in which the crystalline rocks of the Archaean craton are unconformably overlain by Ketilidian supracrustal rocks; (2) a major polyphase pluton, referred to as the Julianehåb batholith; and (3) extensive areas of Ketilidian supracrustal rocks, divided into psammitic and pelitic rocks with subordinate interstratified mafic volcanic rocks (Fig. 1). The Julianehåb batholith is viewed as emplaced in a magmatic arc setting; the supracrustal sequences south of the batholith have been interpreted as either (1) deposited in an intra-arc and fore-arc basin (Chadwick & Garde, 1996), or (2) deposited in a back-arc or intra-arc setting (Stendal & Swager, 1995; Swager, 1995). Both possibilities are plausible and infer subduction-related processes. Regional compilations of geological, geochemical and geophysical data for southern Greenland have been presented by Thorning et al. (1994). Mosher (1995) has recently reviewed the mineral exploration potential of the region. The commercial company Nunaoil A/S has been engaged in gold prospecting in South Greenland since 1990 (e.g. Gowen et al., 1993). A principal goal of the SUPRASYD project was to test the mineral potential of the Ketilidian supracrustal sequences and define the gold potential in the shear zones in the Julianehåb batholith. Previous work has substantiated a gold potential in amphibolitic rocks in the south-west coastal areas (Gowen et al., 1993.), and in the amphibolitic rocks of the Kutseq area (Swager et al., 1995). Field work in 1996 was focused on prospective gold-bearing sites in mafic rocks in South-East Greenland. Three M.Sc. students mapped showings under the supervision of the H. S., while an area on the south side of Kangerluluk fjord was mapped by H. S. and W. M. (Fig. 4).

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