Non-Conductive Volcanogenic Massive Sulphide Mineralization in the Pilbara Area of Western Australia

1984 ◽  
Vol 15 (3) ◽  
pp. 143-153 ◽  
Author(s):  
P. J. Gunn
Keyword(s):  
Western Australia ◽  
Massive Sulphide ◽  
Sulphide Mineralization ◽  
Volcanogenic Massive Sulphide

Geological setting, U–Pb geochronology, and radiogenic isotopic characteristics of the Permo-Triassic Kutcho Assemblage, north-central British Columbia

1997 ◽  
Vol 34 (10) ◽  
pp. 1310-1324 ◽  
Author(s):  
Fiona C. Childe ◽  
John F.H. Thompson
Keyword(s):  
Hanging Wall ◽  
Volcanic Rocks ◽  
Isotopic Signature ◽  
Massive Sulphide ◽  
Pyroclastic Flows ◽  
Sulphide Mineralization ◽  
Isotopic Signatures ◽  
Arc Magmas ◽  
Volcanogenic Massive Sulphide ◽  
Mass Flows

The Kutcho Assemblage is a latest Permian to Early Triassic volcano-sedimentary sequence within the fault-bounded King Salmon Allochthon. Volcanic and volcaniclastic rocks consist of massive to pillowed flows and tuffs of basaltic to basaltic andesitic composition, as well as flows, mass flows, and pyroclastic flows of rhyodacitic to rhyolitic composition. The volcanic sequence is intruded by gabbro, diorite, trondhjemite, and quartz–plagioclase porphyry. Volcanic and intrusive rocks have tholeiitic magmatic affinities, with die exception of the gabbro sills and dykes, which are chemically similar to alkaline arc magmas. Cu–Zn volcanogenic massive sulphide mineralization at die Kutcho Creek deposit is hosted by rhyolite mass flows near me top of the Kutcho Assemblage. Rhyolite mass flows from the hanging wall and footwall to mineralization have U–Pb ages of 242 ± 1 and [Formula: see text], respectively, whereas a quartz–plagioclase porphyritic intrusion to the south of the mineralization has a U–Pb age of 244 ± 6 Ma. The dates determined in this study constrain a previously unknown age for massive sulphide mineralization in the Canadian Cordillera. Furthermore, the age of the Kutcho Assemblage and the primitive Pb isotopic signature of its contained syngenetic mineralization (207Pb/206Pb = 0.83988–0.84112 and 208Pb/206Pb = 2.0517–2.0556) are inconsistent with formation as part of the adjacent Stikine or Quesnel terranes. Primitive Nd isotopic signatures (εNd(initial) = +7.5 to +9.1) and trace and rare earth element chemistry indicate that volcanic rocks of the Kutcho Assemblage, related intrusions, and volcanogenic massive sulphide mineralization formed in an intraoceanic island arc environment, probably directly on oceanic crustal basement. Gabbro sills and dykes, which are interpreted to be slightly younger than volcanic rocks of the Kutcho Assemblage, appear to have formed in response to a change in the tectonic regime, perhaps as a result of a collisional event.

Volcanic reconstruction of Paleoproterozoic arc volcanoes: the Hidden and Louis formations, Flin Flon, Manitoba, CanadaThis is a companion paper to DeWolfe, Y.M., Gibson, H.L., and Piercey, S.J. 2009. Petrogenesis of the 1.9 Ga mafic hanging wall sequence to the Flin Flon, Callinan, and Triple 7 massive sulphide deposits, Flin Flon, Manitoba, Canada. Canadian Journal of Earth Sciences, 46: this issue.

2009 ◽  
Vol 46 (7) ◽  
pp. 481-508 ◽  
Author(s):  
Y. M. DeWolfe ◽  
H. L. Gibson ◽  
B. Lafrance ◽  
A. H. Bailes
Keyword(s):  
Hanging Wall ◽  
Massive Sulphide ◽  
Gradual Change ◽  
Shield Volcano ◽  
Ore Formation ◽  
Massive Sulphide Deposits ◽  
Volcanogenic Massive Sulphide ◽  
Volcaniclastic Rocks ◽  
Flin Flon ◽  
Sulphide Deposits

The hanging wall to the Flin Flon, Callinan, and Triple 7 volcanogenic massive sulphide deposits of the Flin Flon district is composed of the Hidden and Louis formations. The contact between these formations is marked by mafic tuff that represents a hiatus in effusive volcanism. The formations form a composite volcanic edifice that was erupted and grew within a large, volcanic–tectonic subsidence structure (hosting the deposits) that developed within a rifted-arc environment. The formations are evidence of resurgent effusive volcanism and subsidence following a hiatus in volcanism marked by ore formation since they consist of dominantly basaltic flows, sills, and volcaniclastic rocks with subordinate basaltic andesite and rhyodacitic flows and volcaniclastic rocks. The Hidden formation is interpreted to represent a small shield volcano and the Louis formation a separate shield volcano that developed on its flank. Both the Hidden and Louis volcanic edifices were constructed by continuous, low-volume eruptions of pillow lava. A gradual change from a dominantly extensional environment during the formation of the footwall Flin Flon formation to a progressively more dominant convergent environment during the emplacement of the hanging wall suggests that the Hidden and Louis formations are unlikely to host significant volcanogenic massive sulphide-type mineralization. However, synvolcanic structures in the formations define structural corridors that project downwards into the footwall where they encompass massive sulphide mineralization, indicating their control on ore formation, longevity,and reactivation as magma and fluid pathways during the growth of the Hidden and Louis volcanoes.

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