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Paleomagnetic events in the brunhes and Matuyama epochs identified from magnetic profiles reduced to the pole

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Abstract

Eleven oceanic magnetic profiles associated with the paleomagnetic time scale younger than the beginning of the Matuyama epoch (2.43 my) have been reduced to the pole, altered to conform to a 3 cm yr-1 spreading rate, and then all halves added and averaged to obtain a representative symmetric magnetic profile. This final stacked profile emphasizes the subtle anomalies associated with minor paleomagnetic events and minimizes randomly occurring anomalies. The axial anomaly of the stacked profile shows no evidence of the Laschamp event (centered at 0.025 my); however, a minimum at 0.15 my may correspond to the Blake event. A physical model of the stacked magnetic profile consists of a thin, highly magnetized layer with a 40% magnetization decrease at 10 km from the profile center. Magnetization values were modified from Irving and Talwani and the Blake event included. The stacked profile shows two minor anomalies centered at 1.97 my and 2.17 my. The younger anomaly corresponds with the younger Olduvai event (centered at 1.965 my) on the Cox time scale and the W anomaly (centered at 1.99 my) of Emilia and Heinrichs. The older anomaly lies between the older Olduvai event (2.12 my) of Cox and the X anomaly of Heirtzler, and Emilia and Heinrichs; additional work is required to assess the significance of this older event.

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References

  • Baranov, V.: 1957, ‘A New Method for Interpretation of Aeromagnetic Maps: Pseudo-Gravimetric Anomalies’, Geophysics 22, 359–383.

    Google Scholar 

  • Baranov, V. and Naudy, H.: 1964, ‘Numerical Calculation of the Formula of Reduction to the Magnetic Pole’, Geophysics 29, 67–79.

    Google Scholar 

  • Bhattacharyya, B. K.: 1965, ‘Two-Dimensional Harmonic Analysis as a Tool for Magnetic Interpretation’, Geophysics 30, 829–857.

    Google Scholar 

  • Blakely, R. J. and Cox, A.: 1971, ‘Binary Model for Two-Dimensional Magnetic Anomalies’, Earth Planetary Sci. Letters 12, 108–118.

    Google Scholar 

  • Bonhommet, N. and Babkine, J.: 1967, ‘Sur la Présence d'Aimantations Inversées dans la Chaîne des Puys’, Compt. Rend. Acad. Sci. Paris 264, 92.

    Google Scholar 

  • Bonhommet, N. and Zahringer, J.: 1969, ‘Paleomagnetism and Potassium Argon Age Determinations of the Laschamp Geomagnetic Polarity Events, Earth Planetary Sci. Letters 6, 43–46.

    Google Scholar 

  • Bott, M. H. P.: 1967, ‘Solution of the Linear Inverse Problem in Magnetic Interpretation with Application to Oceanic Magnetic Anomalies’, Geophys. J. Roy. Astron. Soc. 13, 313–323.

    Google Scholar 

  • Bott, M. H. P. and Hutton, M. A.: 1970, ‘Limitations on the Resolution Possible in the Direct Interpretation of Marine Magnetic Anomalies’, Earth Planetary Sci. Letters 8, 317–319.

    Google Scholar 

  • Cox, A.: 1969, ‘Geomagnetic Reversals’, Science 163, 237–245.

    Google Scholar 

  • Denham, C. R. and Cox, A.: 1971, ‘Evidence that the Laschamp Polarity Event did not Occur 13300-30400 years ago’, Earth Planetary Sci. Letters 13, 181–190.

    Google Scholar 

  • Dickson, G. O., Pitman, W. C.III, and Heirtzler, J. R.: 1968, ‘Magnetic Anomalies in the South Atlantic and Ocean Floor Spreading’, J. Geophys. Res. 73, 2087–2100.

    Google Scholar 

  • Emilia, D. A.: 1972, ‘Equivalent Sources Used as an Analytic Base for Processing Two-Dimensional Magnetic Fields’, in preparation.

  • Emilia, D. A. and Bodvarsson, G.: 1969, ‘Numerical Methods in the Direct Interpretation of Marine Magnetic Anomalies’, Earth Planetary Sci. Letters 7, 194–200.

    Google Scholar 

  • Emilia, D. A. and Bodvarsson, G.: 1970, ‘More on the Direct Interpretation of Magnetic Anomalies’, Earth Planetary Sci. Letters 8, 320–321.

    Google Scholar 

  • Emilia, D. A. and Heinrichs, D. F.: 1969, ‘Ocean Floor Spreading: Olduvai and Gilsa Events in the Matuyama Epoch’, Science 166, 1267–1269.

    Google Scholar 

  • Glass, B., Ericson, D. B., Heezen, B. C., Opdyke, N. D., and Glass, J. A.: 1967, ‘Geomagnetic Reversals and Pleistocene Chronology’, Nature 216, 437–442.

    Google Scholar 

  • Grim, P. J.: 1970, ‘Connection of the Panama Fracture Zone with the Galapagos Rift Zone, Eastern Tropical Pacific’, Marine Geophys. Res. 1, 85–90.

    Google Scholar 

  • Heirtzler, J. R., Dickson, G. O., Herron, E. M., Pitman, W. C.III, and Le Pichon, X.: 1968, ‘Marine Magnetic Anomalies, Geomagnetic Field Reversals, and Motions of the Ocean Floor and Continents’, J. Geophys. Res. 73, 2119–2136.

    Google Scholar 

  • Irving, E.: 1970, ‘The Mid-Atlantic Ridge at 45° N. XIV. Oxidation and Magnetic Properties of Basalt; Review and Discussion’, Can. J. Earth Sci. 7, 1528–1538.

    Google Scholar 

  • Irving, E., Park, J. K., Haggerty, S. E., Aumento, F., and Loncarevic, B.: 1970, ‘Magnetism and Opaque Mineralogy of Basalts from the Mid-Atlantic Ridge at 45° N’, Nature 228, 974–976.

    Google Scholar 

  • Johnson, W. W.: 1969, ‘A Least-Squares Method of Interpreting Magnetic Anomalies Caused by Two-Dimensional Structures’, Geophysics 34, 65–74.

    Google Scholar 

  • Le Pichon, X. and Heirtzler, J. R.: 1968, ‘Magnetic Anomalies in the Indian Ocean and Sea-Floor Spreading’, J. Geophys. Res. 73, 2101–2117.

    Google Scholar 

  • Ninkovitch, D., Opdyke, N. D., Heezen, B. C., and Foster, J. H.: 1966, ‘Paleomagnetic Stratigraphy, Rates of Deposition and Tephrachronology in North Pacific Deep-Sea Sediments’, Earth Planetary Sci. Letters 1, 476–492.

    Google Scholar 

  • Pitdman, W. C.III, Herron, E. M., and Heirtzler, J. R.: 1968, ‘Magnetic Anomalies in the Pacific an Sea Floor Spreading’, J. Geophys. Res. 73, 2069–2085.

    Google Scholar 

  • Smith, J. D. and Foster, J. H.: 1969, ‘Geomagnetic Reversal in the Brunhes Normal Polarity Epoch’, Science 163, 565–567.

    Google Scholar 

  • Talwani, M., Windisch, C. C., and Langseth, M. G.Jr.: 1971, ‘Reykjanes Ridge Crest: A Detailed Geophysical Study’, J. Geophys. Res. 76, 473–517.

    Google Scholar 

  • Watkins, N. D.: 1967, ‘Paleomagnetic Evidence from Oregon for a Return to Shallow ‘Transitional’ Geomagnetic Inclination Following an Upper Miocene Geomagnetic Polarity Change’, Trans Amer. Geophys Union 48, abstr., 83.

    Google Scholar 

  • Watkins, N. D.: 1968, ‘Short Period Geomagnetic Polarity Events in Deep-Sea Sedimentary Cores’, Earth Planetary Sci. Letters 4, 341–349.

    Google Scholar 

  • Watkins, N. D. and Abdel-Monem, A.: 1971, ‘Detection of the Gilsa Geomagnetic Polarity Event on the Island of Madeira’, Geol. Soc. Amer. Bull. 82, 191–198.

    Google Scholar 

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This material was presented at the Fall Annual Meeting of the American Geophysical Union, December 8, 1971.

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Emilia, D.A., Heinrichs, D.F. Paleomagnetic events in the brunhes and Matuyama epochs identified from magnetic profiles reduced to the pole. Marine Geophysical Researches 1, 436–444 (1972). https://doi.org/10.1007/BF00286745

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  • DOI: https://doi.org/10.1007/BF00286745

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