<p> Pseudotachylites within the Levack Gneisses of the North Range Sudbury
Structure were studied, with an emphasison petrography, major oxide chemistry, and
paleomagnetism. </p> <p> The pseudotachylites are present as dark greyish green veins and larger scale
breccia zones. The matrix is glassy and aphanitic and the fragments, mostly quartz and
feldspar are subangular to subrounded. The larger fragments and the wall rock contain
kink bands in biotites and planar features in feldspars and quartz. The planar features are
defined by rows of parallel inclusions and are diagnostic of shock metamorphism when
parallel to specific crystallographic orientations of quartz. The major oxide chemistry
shows the pseudotachylites are enriched in total iron, magnesia and lime. This
corresponds to other impact-generated pseudotachylite chemistries. Thus, these rocks
are not a product of pure wall rock and either the mafics were selectively melted out or
added from an external source. </p> <p> Paleomagnetic analysis confirms the age of the pseudotachylite is approximately
the same as the North Range of the Sudbury Structure, the least deformed component.
Thus whatever the event was it also formed the pseudotachylite. The fact that the
pseudotachylite contains shock metamorphic features, supports that the event was likely
an impact, as of yet the only known process capable of producing the required pressures,
temperatures and strain rates. </p> / Thesis / Bachelor of Science (BSc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/19546 |
| Date | 04 1900 |
| Creators | Blonde, Julie |
| Contributors | Burley, B.J., Geology |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
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