| Title | Tracking the Late Jurassic apparent (or true) polar shift in U-Pb-dated kimberlites from cratonic North America (Superior Province of Canada) |
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| Author | Kent, D V; Kjarsgaard, B A ; Gee, J S; Muttoni, G; Heaman, L M |
| Source | Geochemistry, Geophysics, Geosystems (G3) vol. 16, issue 4, 2015 p. 983-994, https://doi.org/10.1002/2015GC005734  Open Access |
| Image |  |
| Year | 2015 |
| Alt Series | Earth Sciences Sector, Contribution Series 20150057 |
| Publisher | Wiley-Blackwell |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Ontario; Manitoba; Northwest Territories; Nunavut; Northern offshore region |
| NTS | 41; 42; 43; 53; 54; 55; 56; 57; 58; 59; 63; 64; 65; 66; 67; 68; 69; 76; 77; 78; 79; 86; 87; 88; 89; 96; 97; 98; 99; 106; 107; 116; 117 |
| Area | Arctic; Canada; United States of America |
| Lat/Long WENS | -152.0000 -88.0000 85.0000 35.0000 |
| Subjects | geochronology; polar wandering; uranium lead dates; uranium lead dating; kimberlites; paleomagnetic poles; paleomagnetism; paleomagnetic interpretations; Superior Province; Mesozoic; Jurassic |
| Illustrations | location maps; plots |
| Program | GEM:
Geo-mapping for Energy and Minerals Diamonds |
| Released | 2015 04 02 |
| Abstract | Different versions of a composite apparent polar wander (APW) path of variably selected global poles assembled and averaged in North American coordinates using plate reconstructions show either a smooth
progression or a large (~30°) gap in mean paleopoles in the Late Jurassic, between about 160 and 145 Ma. In an effort to further examine this issue, we sampled accessible outcrops/subcrops of kimberlites associated with high-precision U-Pb perovskite
ages in the Timiskaming area of Ontario, Canada. The 154.9?±?1.1 Ma Peddie kimberlite yields a stable normal polarity magnetization that is coaxial within less than 5° of the reverse polarity magnetization of the 157.5?±?1.2 Ma Triple B kimberlite.
The combined ~156 Ma Triple B and Peddie pole (75.5°N, 189.5°E, A95?=?2.8°) lies about midway between igneous poles from North America nearest in age (169 Ma Moat volcanics and the 146 Ma Ithaca kimberlites), showing that the polar motion was at a
relatively steady yet rapid (~1.5°/Myr) pace. A similar large rapid polar swing has been recognized in the Middle to Late Jurassic APW path for Adria-Africa and Iran-Eurasia, suggesting a major mass redistribution. One possibility is that slab
breakoff and subduction reversal along the western margin of the Americas triggered an episode of true polar wander. |
| Summary | (Plain Language Summary, not published)
Integrated age determinations and paleomagnetic data are used to examine earth-scale plate tectonic processes during the time period 160 to 145
Ma. |
| GEOSCAN ID | 296438 |
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