U-Pb Geochronology of the Blake River Group, Abitibi Greenstone Belt, Quebec, and Implications for Base Metal Exploration

被引:0
|
作者
McNicoll, Vicki [1 ]
Goutier, Jean [2 ]
Dube, Benoit [3 ]
Mercier-Lancevin, Patrick [3 ]
Ross, Pierre-Simon [4 ]
Dion, Claude [5 ]
Monecke, Thomas [6 ]
Legault, Marc [2 ]
Percival, John [1 ]
Gibson, Harold [7 ]
机构
[1] Geol Survey Canada, Ottawa, ON K1A 0E8, Canada
[2] Minist Ressources Nat & Faune, Rouyn Noranda, PQ J9X 6R1, Canada
[3] Geol Survey Canada, Quebec City, PQ G1K 9A9, Canada
[4] Ctr Eau Terre Environm, Inst Natl Rech Sci, Quebec City, PQ G1K 9A9, Canada
[5] Minist Ressources Nat & Faune, Val Dor Quebec, PQ J9P 3L4, Canada
[6] Colorado Sch Mines, Golden, CO 80401 USA
[7] Laurentian Univ, Sudbury, ON P3E 2C6, Canada
关键词
MASSIVE SULFIDE DEPOSIT; ANDESITIC VOLCANICLASTIC ROCKS; COPPER-DEPOSIT; NORANDA; EVOLUTION; PART; ONTARIO; CANADA; LITHOGEOCHEMISTRY; STRATIGRAPHY;
D O I
10.2113/econgeo.109.1.27
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
The 2704 to 2695 Ma Blake River Group in the southern Abitibi greenstone belt comprises a well preserved submarine volcanic sequence that hosts a large number of VMS and important Au-rich VMS deposits, including the world-class Horne and LaRonde-Penna deposits. Establishing precise chronostratigraphic control on the VMS deposits within the Blake River Group is critical because numerous distinct events took place within a period of 9 m.y. Nineteen new high-precision U-Pb ages temporally constrain the host rocks of many polymetallic VMS deposits and associated synvolcanic intrusions, demonstrating that these VMS deposits formed throughout the protracted volcanic evolution of the entire group. Ages on host rocks of the Houle (2702.2 +/- 0.9 Ma), Quemont (2702.0 +/- 0.8 Ma), and Fabie (2701.9 +/- 0.9 Ma) deposits reveal that they are among the oldest VMS deposits in the Blake River Group. The giant Horne Au-rich VMS deposit had already formed when the Cu-Zn deposits of the Noranda mine sequence, including Millenbach and Amulet, were generated at similar to 2698 Ma and is thus unrelated, consistent with its different volcanological setting and metal content. Large Au-rich VMS deposits of the Bousquet Formation, including LaRonde Penna and Bousquet 2-Dumagami, were formed at 2698 to 2697 Ma and are distinctly younger than the Home and Quemont deposits. There were, therefore, two major time-stratigraphic intervals within the Blake River Group that were favorable for the formation of Au-rich VMS deposits. Rhyolite hosting the large Bouchard-Hebert VMS deposits yielded an age of 2695.8 +/- 0.8 Ma. Important mineralizing events in the Blake River Group occur at ca. 2-m.y. intervals apart and are associated with major magmatic episodes. Recognition of specific time-stratigraphic intervals for different styles of mineralization and geologic settings is essential to improve exploration models within the Blake River Group and for similar volcanic assemblages elsewhere in the Archean.
引用
收藏
页码:27 / 59
页数:33
相关论文
共 50 条