The Petrochemistry and Origin of the Bourne Complex, Northwestern Ellesmere Island, Canada
New petrological and petrochemical analyses provide insight into the origin of the hypabyssal and volcanic rocks of the Bourne Complex, northwestern Ellesmere Island, Canada. Field relationships and petrographic characteristics reveal three groups of igneous rocks within the Complex: 1) Porphyritic...
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ftdalhouse:oai:DalSpace.library.dal.ca:10222/80227 2023-05-15T16:05:55+02:00 The Petrochemistry and Origin of the Bourne Complex, Northwestern Ellesmere Island, Canada Henry, Andrew S. 2021-01-27T21:04:36Z http://hdl.handle.net/10222/80227 unknown http://hdl.handle.net/10222/80227 Report 2021 ftdalhouse 2021-12-29T18:20:24Z New petrological and petrochemical analyses provide insight into the origin of the hypabyssal and volcanic rocks of the Bourne Complex, northwestern Ellesmere Island, Canada. Field relationships and petrographic characteristics reveal three groups of igneous rocks within the Complex: 1) Porphyritic Andesite (PA), 2) Plagioclase Porphyry dykes (PD), and 3) North-trending dykes (ND). Immobile trace element, and minor element ratios define the tectonomagmatic character of the Complex. Cluster analysis, using ratios of Y, Nb, Zr, TiO2, and P2O5, confirms the petrographic classification. An Nb/Y - Zr/Ti discrimination diagram indicates that the PA are andesitic, that the PD have subalkaline basalt compositions, and that the ND are alkali basalt transitional to basanite. Ti-Y-Zr and Hf-Ta-Th tectonic discriminator diagrams indicate that the PA belong to a destructive plate margin setting, that the PD indicate a destructive plate margin transitional to backarc basin setting and that the ND show a within plate setting. 40Ar/39Ar isotope dating of primary hornblende from the PA yields an age of 380 +/- 10 mya. The PA may relate to magmatism resulting from the transpressive accretion of the Pearya terrane, ca. 390 mya., whereas the PD likely relate to backarc magmatism resulting from the Ellesmerian Orogeny, ca. 360 mya. Calcalkaline magmatism associated with the docking of Pearya may have been much more widespread than previously suspected. Keywords: Ellesmere Island, Bourne Complex, Igneous petrology, Calcalkaline magmatism, Trace element geochemistry, Tectonomagmatic discrimination 40Ar/39Ar dating Pages: 128 Supervisor: Gunter Muecke Report Ellesmere Island Dalhousie University: DalSpace Institutional Repository Canada Ellesmere Island Gunter ENVELOPE(-66.511,-66.511,-68.993,-68.993) |
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Dalhousie University: DalSpace Institutional Repository |
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description |
New petrological and petrochemical analyses provide insight into the origin of the hypabyssal and volcanic rocks of the Bourne Complex, northwestern Ellesmere Island, Canada. Field relationships and petrographic characteristics reveal three groups of igneous rocks within the Complex: 1) Porphyritic Andesite (PA), 2) Plagioclase Porphyry dykes (PD), and 3) North-trending dykes (ND). Immobile trace element, and minor element ratios define the tectonomagmatic character of the Complex. Cluster analysis, using ratios of Y, Nb, Zr, TiO2, and P2O5, confirms the petrographic classification. An Nb/Y - Zr/Ti discrimination diagram indicates that the PA are andesitic, that the PD have subalkaline basalt compositions, and that the ND are alkali basalt transitional to basanite. Ti-Y-Zr and Hf-Ta-Th tectonic discriminator diagrams indicate that the PA belong to a destructive plate margin setting, that the PD indicate a destructive plate margin transitional to backarc basin setting and that the ND show a within plate setting. 40Ar/39Ar isotope dating of primary hornblende from the PA yields an age of 380 +/- 10 mya. The PA may relate to magmatism resulting from the transpressive accretion of the Pearya terrane, ca. 390 mya., whereas the PD likely relate to backarc magmatism resulting from the Ellesmerian Orogeny, ca. 360 mya. Calcalkaline magmatism associated with the docking of Pearya may have been much more widespread than previously suspected. Keywords: Ellesmere Island, Bourne Complex, Igneous petrology, Calcalkaline magmatism, Trace element geochemistry, Tectonomagmatic discrimination 40Ar/39Ar dating Pages: 128 Supervisor: Gunter Muecke |
format |
Report |
author |
Henry, Andrew S. |
spellingShingle |
Henry, Andrew S. The Petrochemistry and Origin of the Bourne Complex, Northwestern Ellesmere Island, Canada |
author_facet |
Henry, Andrew S. |
author_sort |
Henry, Andrew S. |
title |
The Petrochemistry and Origin of the Bourne Complex, Northwestern Ellesmere Island, Canada |
title_short |
The Petrochemistry and Origin of the Bourne Complex, Northwestern Ellesmere Island, Canada |
title_full |
The Petrochemistry and Origin of the Bourne Complex, Northwestern Ellesmere Island, Canada |
title_fullStr |
The Petrochemistry and Origin of the Bourne Complex, Northwestern Ellesmere Island, Canada |
title_full_unstemmed |
The Petrochemistry and Origin of the Bourne Complex, Northwestern Ellesmere Island, Canada |
title_sort |
petrochemistry and origin of the bourne complex, northwestern ellesmere island, canada |
publishDate |
2021 |
url |
http://hdl.handle.net/10222/80227 |
long_lat |
ENVELOPE(-66.511,-66.511,-68.993,-68.993) |
geographic |
Canada Ellesmere Island Gunter |
geographic_facet |
Canada Ellesmere Island Gunter |
genre |
Ellesmere Island |
genre_facet |
Ellesmere Island |
op_relation |
http://hdl.handle.net/10222/80227 |
_version_ |
1766401835686428672 |