On the Reliability (Remagnetization?) of Paleomagnetic Poles Obtained from Permo-Silurian Rocks from Oaxaca Mexico, Belize and Guatemala: Insights from Rock Magnetic Studies

DOI: 10.4236/ojg.2012.22005   PDF   HTML     3,655 Downloads   6,923 Views  


In the reconstruction of past movements of tectonic plates, the determination of reliable paleomagnetic poles is of utmost importance. To achieve accurate results, a full knowledge of the rock magnetic properties of the samples is required particularly for Curie point, for grain-size analyses in addition to thermal and alternating field (a.f.) demagnetization experiments. We present the comparative results of 20 sites drilled at 3 different Paleozoic areas: The Permian rocks of the Juchatengo area in Oaxaca, Mexico; the Late Silurian (~418 Ma) Mountain Pine Ridge Granite, the Hummingbird Granite in Belize, and the Early Leonardian Chochal Limestone in Guatemala. The samples of all 20 sites were subjected to a.f. and thermal demagnetization in 16 steps from NRM to 100 mT, the thermally demagnetized samples were cleaned in 15 increasing temperature steps from NRM up to 675℃. Principal component analysis was applied to the samples in order to obtain their respective mean directions. Saturation Isothermal Remanent Magnetization (SIRM), hysteresis loops, and coercivity experiments performed indicate that about 90% of the samples were characterized by Multi-Domain (MD) grain sizes and the rest were in the Pseudo-Single Domain (PSD) range of the Day diagram. Curie point determinations results ranged from 190℃ to 660℃, indicating the presence of titanomagnetites as well as hematite. In the Juchatengo area reliable poles were obtained from 3 sites, in Belize 3 sites and only 2 sites of the Permian Chochal Formation, Guatemala yielded coherent and useful results. All the “reliable” paleopoles obtained do not agree with the APWP of North America.

Share and Cite:

J. Guerrero-Garcia and E. Herrero-Bervera, "On the Reliability (Remagnetization?) of Paleomagnetic Poles Obtained from Permo-Silurian Rocks from Oaxaca Mexico, Belize and Guatemala: Insights from Rock Magnetic Studies," Open Journal of Geology, Vol. 2 No. 2, 2012, pp. 48-56. doi: 10.4236/ojg.2012.22005.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] C. G. Dixon, “Geology of Southern British Honduras, with Notes on Adjacent Areas,” Belize Government Printer, Belmopan, 1955, p. 85.
[2] J. H. Bateson, “New Interpretation of Geology of Maya Mountains, British Honduras,” American Association of Petroleum Geologists Bulletin, Vol. 56, No. 5, 1972, pp. 956-963.
[3] J. H. Bateson and I. H. S. Hal, “Geological Map of the Maya Mountains, British Honduras,” American Association of Petroleum Geologists Bulletin, Vol. 56, 1975, pp. 529-530.
[4] J. H. Bateson and I. H. S. Hall, “The Geology of the Maya Mountains-Belize,” Institute of Geological Sciences Overseas Memoir 3, Her Majesty’s Stationary Office, London, 1977, p. 42.
[5] M. B. Steiner and J. D. Walker, “Late Silurian Plutons in Yucatan,” Journal of Geophysical Research, Vol. 101, No. 8, 1996, pp. 17727-17735. doi:10.1029/96JB00174
[6] T. H. Anderson, B. Burkart, R. E. Clemons, O. H. Bohnenberger and D. N. Blount, “Geology of the Western Altos Cuchumatanes, Northwestern Guatemala,” Geological Society of America Bulletin, Vol. 84, No. 3, 1973, pp. 805-826. doi:10.1130/0016-7606(1973)84<805:GOTWAC>2.0.CO;2
[7] G. Dengo, “Problems of Tectonic Relations between Central America and the Caribbean,” Transactions of the Gulf Coast Association of Geological Societies, Vol. 19, 1969, pp. 311-320.
[8] J. M. Grajales-Nishimura, E. Centeno-Garcia, J. D. Keppie and J. Dostal, “Geochemistry of Paleozoic Basalts from the Juchatengo Complex of Southern Mexico: Tectonic Implications,” Journal of South American Earth Sciences, Vol. 12, No. 6, 1999, pp. 537-544. doi:10.1016/S0895-9811(99)00037-1
[9] J. L. Kirschvink, “The Least-Squares Line Plane and Analysis of Paleomagnetic Data,” Geophysical Journal of the Royal Astronomical Society, Vol. 45, 1980, pp. 699-718.
[10] R. A. Fisher, “Dispersion on a SPHERe,” Proceedings of the Royal Society of London, Vol. A217, No. 1130, 1953, pp. 295-305.
[11] R. Day, M. D. Fuller and V. Schmidt, “Hysteresis Properties of Titanomagnetites: Grain Size and Compositional Dependence,” Physics of the Earth and Planetary Interiors, Vol. 13, No. 4, 1977, pp. 260-267. doi:10.1016/0031-9201(77)90108-X
[12] D. J. Dunlop, “Theory and Application of the Day Plot (Mrs/Ms versus Hcr/Hc) 1. Theoretical Curves and Tests Using Titanomagnetite Data,” Journal of Geophysical Research, Vol. 107, 2002, p. 22. doi:10.1029/2001JB000486
[13] M. J. Steiner, “Pangean Reconstruction of the Yucatan Block: Its Permian, Triassic, and Jurassic Geologic and Tectonic History,” Geological Society of America, Special Paper, Vol. 393, 2006, pp. 457-480.
[14] M. W. McElhinny and P. L. McFadden, “Paleomagnetism, Continents and Oceans,” Academic Press, International Geophysics Series, San Diego, Vol. 73, 2000, p. 382.
[15] J. D. A. Zijderveld, “A.C. Demagnetization of Rocks,” In: D. W. Collinson, K. M. Creer and S. K. Runcorn, Eds., Methods in Paleomagnetism, Elsevier, New York, 1967, pp. 256-286.

comments powered by Disqus

Copyright © 2020 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.