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Paleomagnetism of Pliocene to Pleistocene lava flows in the northern part of Hyogo prefecture, Southwest Japan and Brunhes Chron paleosecular variation in Japan

Abstract

Paleomagnetic investigation was performed on 26 Potassium-Argon dated Pliocene to Pleistocene lava flows, collected at 34 sites from northern Hyogo, Southwest Japan. Most magnetic polarities were found to be coincident with the geomagnetic polarity timescale (GPTS), although two lava flows do not agree with the timescale. One of 2 lava flows incompatible with the GPTS, the Oliveine Andesite lava flow from the Oginosen volcano group dated at 0.92 + / − 0.05Ma, shows normal polarity. This finding is a possible evidence confirming the existence of the Santa Rosa Event proposed recently. Twenty-two paleomagnetic data sets were used to investigate paleosecular variation (PSV) having passed the following criteria: 1) characteristic components are obtained from four specimens or more for a lava flow, 2) ケ95 of the lava flow mean direction is < 10° and 3) the virtual geomagnetic pole (VGP) latitude calculated is > 50° or < −50°. The mean VGP was calculated to be latitude = 85.5°N and longitude = 285.3°E (k = 34.8 and ケ95 = 5.3°). The resultant angular standard deviation (ASD) with respect to the geographic pole was calculated to be 14.5° with the upper limit = 18.3° and the lower limit = 12.1°. The ASD value is almost equal to most existing results from the Japan Islands. Brunhes Chron PSV in Japan was estimated using the identical criteria for selection; 66 of 87 available data sets passed. The mean VGP was calculated to be latitude = 89.3°N and longitude = 14.4°E (k = 33.1 and ケ95 = 3.1°). The resultant ASD with respect to the geographic pole was calculated to be 14.2° with the upper limit = 16.1° and the lower limit = 12.7°. The ASD values for the past 3 million years in northern Hyogo and for the Brunhes Chron in Japan are compatible with the global trend for the past 5 million years fitted by physical PSV Model F and phenomenological PSV Model G. This suggests that the PSV in Japan is not low compared with anomalously low PSV area in the Pacific Region.

References

  • Cande, S. C. and D. V. Kent, Revised calibration of the geomagnetic polarity timescale for the Late Cretaceous and Cenozoic, J. Geophys. Res., 100, 6093–6095, 1995.

    Article  Google Scholar 

  • Cox, A., Analysis of present geomagnetic field for comparison with paleomagnetic results, J. Geomag. Geoelectr., 8, 101–112, 1962.

    Article  Google Scholar 

  • Cox, A., Confidence limits for the precision parameter κ, Geophys. J. R. astr. Soc., 18, 545–549, 1969.

    Article  Google Scholar 

  • Cox, A., Latitude dependence of the angular dispersion of the geomagnetic field, Geophys. J. R. astr. Soc., 20, 253–269, 1970.

    Article  Google Scholar 

  • Doell, R. R. and A. Cox, The pacific geomagnetic secular variation anomaly and the question of lateral uniformity in the lower mantle, The Nature of the Solid Earth, pp. 245–285, McGraw-Hill, New York, 1972.

    Google Scholar 

  • Furuyama, K., Geology of the Teragi Group, Southwest Japan—with special reference to the Terada Volcanics—, J. Geosci. Osaka City Univ., 32, 123–173, 1989.

    Google Scholar 

  • Furuyama, K., K. Nagao, K. Kasatani, and S. Mitsui, K-Ar ages of the Kannabe Volcano Group and the adjacent basaltic monogenetic volcanoes, east San-in district, Earth Science (Chikyuu Kagaku), 47, 377–390, 1993a (in Japanese with English abstract).

    Google Scholar 

  • Furuyama, K., K. Nagao, S. Mitsui, and K. Kasatani, K-Ar ages of Late Neogene monogenetic volcanoes in the east San-in district, Southwest Japan, Earth Science (Chikyuu Kagaku), 47, 519–532, 1993b.

    Google Scholar 

  • Genbudo Research Group, High-P and low-Si and -K Quaternary lava from Genbudo, northern Kinki district, Japan, Earth Science (Chikyuu Kagaku), 43, 231–236, 1989.

    Google Scholar 

  • Genbudo Research Group, Geology and petrology of Quaternary volcanic rocks from the Genbudo area, northern Hyogo Prefecture, southwest Japan—Genbudo and Akaishi lavas—, Earth Science (Chikyuu Kagaku), 45, 131–144, 1991 (in Japanese with English abstract).

    Google Scholar 

  • Heki, K., Paleomagnetic study of the Higashi-Izu monogenetic volcano group and pyroclastic flow deposits in Kagoshima Prefecture: Paleosecular variation during the last 40,000 years in Japan, J. Geomag. Geoelectr., 35, 383–390, 1983.

    Article  Google Scholar 

  • Ishikawa, N. and T. Tagami, Paleomagnetism and fission-track geochronology on the Goto and Tsushima Islands in the Tsushima strait area: Implications for the opening mode of the Japan Sea, J. Geomag. Geoelectr., 43, 229–253, 1991.

    Article  Google Scholar 

  • Kirschvink, J., The least-squares line and plane and the analysis of palaeomagnetic data, Geophys. J. R. astr. Soc., 62, 699–718, 1980.

    Article  Google Scholar 

  • McElhinny, M. W. and R. T. Merrill, Geomagnetic secular variation over the past 5 my, Rev. Geophys. Space Phys., 13, 687–708, 1975.

    Article  Google Scholar 

  • McElhinny, M. W., P. L. McFadden, and R. T. Merrill, The myth of the Pacific dipole window, Earth Planet. Sci. Lett., 143, 13–22, 1996.

    Article  Google Scholar 

  • McFadden, P. L. and M. W. McElhinny, A physical model for palaeosecular variation, Geophys. J. R. astr. Soc., 78, 809–823, 1984.

    Article  Google Scholar 

  • McFadden, P. L., R. T. Merrill, and M. W. McElhinny, Dipole/quadrupole family modeling of paleosecular variation, J. Geophys. Res., 93, 11,583–11,588, 1988.

    Article  Google Scholar 

  • McFadden, P. L., R. T. Merrill, M. W. McElhinny, and S. Lee, Reversals of the Earth’s magnetic field and temporal variations of the dynamo families, J. Geophys. Res., 96, 3923–3933, 1991.

    Article  Google Scholar 

  • Otake, H., H. Tanaka, M. Kono, and K. Saito, Paleomagnetic study of Pleistocene lavas and dikes of the Zao Volcano Group, J. Geomag. Geoelectr., 45, 595–612, 1993.

    Article  Google Scholar 

  • Roberts, P. H. and M. Stix, a-effect dynamos by the Bullard-Gellman formalism, Astron. Astrophys., 18, 453–466, 1972.

    Google Scholar 

  • Sakiyama, T., T. Matsuda, H. Morinaga, A. Goto, and S. Kato, Pliocene to Pleistocene volcanic rocks in northern Hyogo Prefecture, Southwest Japan—K-Ar age, paleomagnetism and major elements—, Humans and Nature, 6, 149–170, 1995 (in Japanese with English abstract).

    Google Scholar 

  • Shibuya, H., J. Cassidy, I. E. M. Smith, and T. Itaya, Paleomagnetism of young New Zealand basalts and longitudinal distribution of paleosecular variation, J. Geomag. Geoelectr., 47, 1011–1022, 1995.

    Article  Google Scholar 

  • Singer, B. S., K. A. Hoffman, A. Chauvin, R. S. Coe, and M. S. Pringle, Dating transitional magnetized lavas of the late Matuyama Chron: Toward a new 40Ar/39Ar timescale of reversals and events, J. Geophys. Res., 104, 679–693, 1999.

    Article  Google Scholar 

  • Tsunakawa, H. and Y. Hamano, Paleomagnetic study of the Ashitaka dike swarm in Central Japan, J. Geomag. Geoelectr., 40, 221–226, 1988.

    Article  Google Scholar 

  • Tsunakawa, H., K. Heki, and K. Amano, Paleomagnetism of the Shimokura dike swarm in Northeast Japan, J. Geomag. Geoelectr., 37, 979–985, 1985.

    Article  Google Scholar 

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Morinaga, H., Matsumoto, T., Okimura, Y. et al. Paleomagnetism of Pliocene to Pleistocene lava flows in the northern part of Hyogo prefecture, Southwest Japan and Brunhes Chron paleosecular variation in Japan. Earth Planet Sp 52, 437–443 (2000). https://doi.org/10.1186/BF03352255

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Keywords

  • Andesite Lava
  • Paleomagnetic Result
  • Virtual Geomagnetic Pole
  • Paleomagnetic Polarity
  • Hyogo Prefecture