Bermuda Hotspot
A 2002 paper proposes that the Bermuda hotspot generated the Mississippi Embayment in the Early Cretaceous Epoch, when the hotspot strengthened and uplifted the present-day Mississippi Valley. The resulting highland eroded over time, and when North American Plate motion moved the valley away from the hotspot, the resulting thinned lithosphere subsided, forming a trough. The seismic zones centered on New Madrid, Missouri, and Charleston, South Carolina, and the volcanic kimberlite pipes in Arkansas are cited as evidence.
Other published reports argue that the lack of a chain of age-progressive seamounts (as in the Hawaiian-Emperor seamount chain), the absence of present-day volcanism, and the elongation of the Bermuda Rise oblique to plate motion are evidence against a hotspot origin for the Bermuda Rise. Others alternatively attribute the Bermuda Rise to a reorganization of plate tectonics associated with the closing of the Tethys Sea, though noting that shallow processes may not explain the source of the magmatism. A more recent paper finds a thinning in the mantle transition zone under Bermuda, apparently consistent with mantle upwelling and a hot lower mantle below Bermuda. A still more recent paper, based on geochemical analysis of a drill core, suggests that Bermuda volcanism sampled a transient mantle reservoir in the mantle transition zone that was formed by chemical recycling related to subduction during the formation of Pangaea.
See also
References
- ^ Vacher, H.L.; Rowe, Mark (1997). Vacher, H.L.; Quinn, T. (eds.). Geology and Hydrogeology of Bermuda, in Geology and Hydrogeology of Carbonate Islands, Developments in Sedimentology 54. Amsterdam: elsevier Science B.V. pp. 35–90. ISBN 9780444516442.
- ^ Cox, Randel T.; Roy B. Van Arsdale (January 2007). "The Mississippi's Curious Origins". Scientific American. 296 (1): 76–82B. Bibcode:2007SciAm.296a..76V. doi:10.1038/scientificamerican0107-76. PMID 17186836.
- ^ Cox, Randel T.; Roy B. Van Arsdale (1997). "Hotspot origin of the Mississippi embayment and its possible impact on contemporary seismicity". Engineering Geology. 46 (3–4): 201–216. Bibcode:1997EngGe..46..201C. doi:10.1016/S0013-7952(97)00003-3.
- ^ Cox, Randel T.; Roy B. Van Arsdale (2002). "The Mississippi Embayment North America: A First Order Continental Structure Generated by the Cretaceaous Superplume Mantle Event". Journal of Geodynamics. 34 (2): 163–176. Bibcode:2002JGeo...34..163C. doi:10.1016/S0264-3707(02)00019-4.
- ^ Nunn, Jeffrey A. (1990). "Relaxation of Continental Lithosphere: an Explanation for Late Cretaceous Reactivation of the Sabine Uplift of Louisiana-Texas". Tectonics. 9 (2): 341–359. Bibcode:1990Tecto...9..341N. doi:10.1029/TC009i002p00341.
- ^
Vogt, Peter R.; Woo-Yeol Jung (2007). Origin of the Bermuda volcanoes and the Bermuda Rise: History, observations, models, and puzzles (PDF). Vol. 430. pp. 553–591. CiteSeerX 10.1.1.484.2851. doi:10.1130/2007.2430(27). ISBN 978-0-8137-2430-0. Retrieved 12 August 2008.
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ignored (help) - ^ Benoit, Margaret H.; Maureen D. Long; Scott D. King (2013). "Anomalously thin transition zone and apparently isotropic upper mantle beneath Bermuda: Evidence for upwelling". Geochemistry, Geophysics, Geosystems. 14 (10): 4282. Bibcode:2013GGG....14.4282B. doi:10.1002/ggge.20277.
- ^ Mazza, Sarah E.; Esteban Gazel; Michael Bizimis; Robert Moucha; Paul Béguelin; Elizabeth A. Johnson; Ryan McAleer; Alexander V. Sobolev (2019). "Sampling the volatile-rich transition zone beneath Bermuda". Nature. 569 (7756): 398–403. Bibcode:2019Natur.569..398M. doi:10.1038/s41586-019-1183-6. PMID 31092940. S2CID 155103393.
32°31′02″N 65°00′57″W / 32.5173°N 65.0158°W