A study of the P-T-t-fluid evolution of the Glennie domain, Trans-Hudson Orogen
| dc.contributor.committeeMember | Kyser, Thomas | en_US |
| dc.creator | Durocher, Kyle Edward | en_US |
| dc.date.accessioned | 2004-10-21T00:05:25Z | en_US |
| dc.date.accessioned | 2013-01-04T05:03:03Z | |
| dc.date.available | 1997-01-01T08:00:00Z | en_US |
| dc.date.available | 2013-01-04T05:03:03Z | |
| dc.date.created | 1997-01 | en_US |
| dc.date.issued | 1997-01-01 | en_US |
| dc.date.submitted | January 1997 | en_US |
| dc.description.abstract | The Glennie domain of the Trans-Hudson Orogen (THO) is characterized by arcuate belts of Paleoproterozoic supracrustal rocks, including island arc volcanogenic assemblages, among variably deformed and metamorphosed granitoid rocks. Four discrete deformation events, termed D1 through D4, have been recorded in the domain. The Santoy Lake area in the central-northern Pine Lake greenstone belt and the Brownell Lake area in the southern Brownell-Wapawekka lakes greenstone belt were chosen as areas in which the P-T-t-fluid histories were ascertained via a myriad of geochemical techniques. Mineral assemblages associated with D2 metamorphism in the Santoy Lake area suggest equilibrium conditions of ca. 500-650°C and 2.5-7 kbar. Similarly, Brownell Lake samples record D2 equilibration at ca. 525-700°C and $>$4 kbar. Garnet-biotite geothermometry from the two areas yield peak (D3) temperatures of ca. 600-690°C for the Santoy Lake area, and ca. 490-590°C for the Brownell Lake area. GASP geobarometry indicates peak and retrograde pressures of ca. 6-8 kbar and ca. 4-6.5 kbar for the Santoy and Brownell lakes areas, respectively. Oxygen isotope geothermometry yields values approximately 50-100°C lower than garnet-biotite temperatures, and do not reflect peak metamorphic conditions. Calculated $\delta\sp{18}$O compositions of these fluids range from 5.4-8.3 permil for Santoy Lake samples and 6.6-12.4 permil for Brownell Lake samples. Intersecting isochores of late secondary fluid inclusions at Santoy Lake show late fluid entrapment at P-T conditions of ca. 150-400°C at 0-3 kbar. Gold showings at Brownell Lake have intersecting secondary inclusion isochores between 100-350°C and 0-1.5 kbar. Five single zircon Pb-evaporation ages of variably deformed granitoid rocks were obtained from the Santoy Lake area. These ages indicate that the D2 event occurred after ca. 1857 Ma, while the D3 and D4 events (and peak metamorphism) occurred after ca. 1815 Ma. The oldest granitoid in the Santoy Lake area provides a minimum age of mafic volcanism in the area and in the Glennie domain of ca. 1886 Ma. 40Ar/39Ar age interpretations suggest the Santoy Lake area is characterized by an initial moderate cooling rate from the time of peak metamorphism until ca. 1725 Ma, followed by a rapid cooling and uplift rate until ca. 1705 Ma, while the Brownell Lake area is characterized by a moderate cooling and uplift rate between peak thermal metamorphism (ca. 1805 Ma) and ca. 1760 Ma, followed by slow uplift and cooling between ca. 1760-1705 Ma. P-T-t conditions of vein emplacement and gold mineralisation differ between the two field areas. Vein emplacement in the Santoy Lake area is associated with the D2 event. The uplift/cooling path suggests that gold precipitated in its present form after ca. 1715 Ma. Vein emplacement and gold mineralisation at Brownell Lake is essentially contemporaneous. The uplift/cooling path suggests that gold precipitated between ca. 1795-1780 Ma. Gold mineralisation in both field areas post-dates the timing of peak metamorphism and late magmatic events in the Glennie domain. The calculated $\delta\sp{18}$O for fluids in equilibrium with vein constituents lie in the range 6.3-8.8 pennil for the Santoy Lake area, and 8.5-11.2 permil for the Brownell Lake area. Observed P-T-t-fluid conditions of mineralisation are similar to Paleoproterozoic and Archean mesothermal-type gold deposits. (Abstract shortened by UMI.) | en_US |
| dc.identifier.uri | http://hdl.handle.net/10388/etd-10212004-000525 | en_US |
| dc.language.iso | en_US | en_US |
| dc.title | A study of the P-T-t-fluid evolution of the Glennie domain, Trans-Hudson Orogen | en_US |
| dc.type.genre | Thesis | en_US |
| dc.type.material | text | en_US |
| thesis.degree.department | Geological Sciences | en_US |
| thesis.degree.discipline | Geological Sciences | en_US |
| thesis.degree.grantor | University of Saskatchewan | en_US |
| thesis.degree.level | Doctoral | en_US |
| thesis.degree.name | Doctor of Philosophy (Ph.D.) | en_US |