| Titre | Magnetic mineralogy of the Yaxcopoil-1 core, Chicxulub |
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| Auteur | Pilkington, M; Ames, D E ; Hildebrand, A R |
| Source | The Chicxulub Scientific Drilling Project; Meteoritics and Planetary Science vol. 39, no. 6, 2004 p. 831-841, https://doi.org/10.1111/j.1945-5100.2004.tb00933.x  Accès ouvert |
| Liens | Abstract - Résumé
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| Liens | The Chicxulub Scientific Drilling Project
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| Image |  |
| Année | 2004 |
| Séries alt. | Commission géologique du Canada, Contributions aux publications extérieures 2003222 |
| Éditeur | Wiley-Blackwell |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1111/j.1945-5100.2004.tb00933.x |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Région | Chicxulub |
| Lat/Long OENS | -90.5000 -88.5000 22.0000 20.2500 |
| Sujets | propriétés magnétiques; susceptibilité magnétique; magnetite; magnétisme rémanent; anomalies magnétiques; levés magnétiques; levés aéromagnétiques; magnétisme; altération; roches mafiques; amphibole;
pyroxene; géologie extraterrestre; géochimie; géophysique; minéraux métalliques; minéralogie |
| Illustrations | profils magnétiques; tableaux; photomicrographies |
| Diffusé | 2004 06 01 |
| Résumé | (disponible en anglais seulement)
Core from the Yaxcopoil-1 (Yax-1) hole, drilled as a result of the Chicxulub Scientific Drilling Project (CSDP), has been analyzed to investigate the
relationship between opaque mineralogy and rock magnetic properties. Twenty one samples of suevite recovered from the depth range 818-894 m are generally paramagnetic, with an average susceptibility of 2000 × 10-6 SI and have weak remanent
agnetization intensities (average 0.1 A/m). The predominant magnetic phase is secondary magnetite formed as a result of low temperature (<150 °C) alteration. It occurs in a variety of forms, including vesicle infillings associated with quartz and
clay minerals and fine aggregates between plagioclase/diopside laths in the melt. Exceptional magnetic properties are found in a basement clast (metamorphosed quartz gabbro), which has a susceptibility of >45000 × 10-6 SI and a remanent magnetization
of 77.5 A/m. Magnetic mafic basement clasts are a common component in the Yax-1 impactite sequence. The high susceptibility and remanence in the mafic basement clasts are caused by the replacement of amphiboles and pyroxenes by an assemblage with
fine <1 um magnetite,
ilmenite, K-feldspar, and stilpnomelane. Replacement of the mafic minerals by the magnetic alteration assemblage occurred before impact. Similar alteration mechanisms, if operative within the melt sheet, could explain the
presence of the high amplitude magnetic anomalies observed at Chicxulub. |
| GEOSCAN ID | 214971 |
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