Abstract
We performed high resolution magnetic measurements on about 180 m of continuous U-channel samples from Sites 1012 (East Cortez Basin) and 1013 (San Nicolas Basin) that were recovered during Ocean Drilling Program Leg 167 to the California Margin. Measurements were made at 1–2 cm intervals from near-complete composite stratigraphic sequences at both of the studied sites with the goal of obtaining high spatial resolution of sediment magnetic properties, including detailed characterization of variations in magnetic mineralogy, concentration, and grain size. The decay of a metastable magnetic mineral or the dissolution of fine-grained magnetite by organic matter reduction had strongly affected both cores, reducing the magnetic intensity to 7%–10% of the initial magnetization. Measurements were carried out ca. 4–6 months after the cores were drilled. Despite the reduced magnetic signal we were able to define a stable characteristic remanence for most of the core. Cyclic variations that were observed over short and long stratigraphic intervals are strongly driven at Earth orbital periodicities and have been used to obtain a detailed age model based on comparison with the insolation record.
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Andreasen, D., M. Flower, M. Harvey, S. Chang, and A. C. Ravelo, Datareport: Late Pleistocene oxygen and carbon isotopic records from ODP Leg 167 Sites 1011, 1012, and 1018. Proceedings of the Ocean Drilling Program, Scientific Results, 167: College Station, TX (Ocean Drilling Program), in press.
Bassinot, F. C., L. D. Labeyrie, E. Vincent, X. Quidelleur, N. J. Shackleton, and Y. Lancelot, The astronomical theory of climate and the age of the Brunhes-Matuyama magnetic reversal, Earth Planet. Sci. Lett., 126, 91–108, 1994.
Bloemendal, J., J. W. King, F. R. Hall, and S. J. Doh, Rock magnetism of late Neogene and Pleistocene deep-sea sediments—relationship to sediment source, diagenetic processes, and sediment lithology, J. Geophys. Res., 97, 4361–4375, 1992.
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.
Canfield, D. E. and R. A. Berner, Dissolution and pyritization of magnetite in anoxic marine environments, Geochim. Cosmochim. Acta, 51, 645–659, 1987.
Emery, K. O., The Sea off Southern California, 336 pp., John Wiley, New Yourk, 1960.
Guyodo, Y., C. Richter, and J.-P. Valet, Paleointensity record from Pleistocene sediments (1.4-0 Ma) off the California Margin, J. Geophys. Res., in press.
Hagelberg, T., N. J. Shackleton, N. Pisias, and Shipboard Scientific Party, Development of composite depth sections for Sites 844 through 854, in Init. Repts., 138 (Pt. 1), edited by L. Mayer, N. Pisias, T. Janecek, et al., pp. 79–85, 107: College Station, TX (Ocean Drilling Program), 1992.
Hayashida, A., K. Verosub, F. Heider, and R. Leonhardt, Magnetostratigraphy and relative paleointensity of pelagic sediments at ODP Site 1010 off Baja California, Geophys. J. Int., in press.
Hayashida, A. and K. Verosub, Magnetic characteristics of surficial marine sediments observed in U-channel samples from ODP Leg 167 Sites 1016 and 1017 (California Margin), Geophys. J. Int., in press.
Heider, F., F. Hufenbecher, U. Draeger, and A. Hayashida, The Brunhes-Matuyama and the upper Jaramillo transitions recorded in sediments from the California Margin (ODP Leg 167). Proceedings of the Ocean Drilling Program, Scientific Results, 167: College Station, TX (Ocean Drilling Program), in press.
Hunt, J. M., Petroleum Geochemistry and Geology, 615 pp., W. H. Freeman, New York, 1979.
Karlin, R., M. Lyle, and G. R. Heath, Authigenic magnetite formation in suboxic marine sediments, Nature, 326, 490–493, 1987.
King, J. W. and J. E. T. Channell, Sedimentary magnetism, environmental magnetism, and magnetostratigraphy. U.S. Natl Rep. Int. Union Geod. Geophys. 1987–1990, Rev. Geophys., 29, 358–370, 1991.
Kirschvink, J. L., The least-squares line and plane and the analysis of paleomagnetic data, Geophys. J. R. Astr. Soc., 62, 699–718, 1980.
Kostra, J. E. and K. H. Nealson, Dissolution and reduction of magnetite by bacteria, Environ. Sci. Technol., 29, 2535–2540, 1995.
Langereis, C. G., M. J. Dekkers, G. J. deLange, M. Paterne, and P. J. M. Van Santvoort, Magnetostratigraphy and astronomical calibration of the last 1.1 Myr from an eastern Mediterranean piston core and dating of short events in the Brunhes, Geophys. J. Int., 129, 75–94, 1997.
Leonhard, R., F. Heider, and A. Hayashida, Relative geomagnetic field intensity across the Jaramillo Subchron in sediments from the California Margin (ODP Leg 167), J. Geophys. Res., in press.
Leslie, B. W., S. P. Lund, and D. E. Hammond, Rock magnetic evidence for the dissolution and authigenic growth of magnetic minerals within anoxic marine sediments of the California Continental Borderland, J. Geophys. Res., 95, 4437–4452, 1990a.
Leslie, B. W., D. E. Hammond, W. M. Berelson, and S. P. Lund, Diagenesis in anoxic sediments from the California Continental Borderland and its influence on iron, sulfur, and magnetite behavior, J. Geophys. Res., 95, 4453–4470, 1990b.
Lu, R. and S. K. Banerjee, Magnetite dissolution in deep sediments and its hydrologic implication-a detailed study of sediments from Site-808, Leg 131, J. Geophys. Res., 99, 9051–9059, 1994.
Lyle, M., I. Koizumi, C. Richter, et al., Proceedings of the Ocean Drilling Program, Initial Reports (Part 1), 495 pp., 167: College Station, TX (Ocean Drilling Program), 1997.
Nagy, E. A. and J.-P. Valet, New advances for paleomagnetic studies of sediment cores using U-channels, Geophys. Res. Lett., 20, 671–674, 1993.
Nowaczyk, N. R., T. W. Frederichs, A. Eisenhauer, and G. Gard, Magnetostratigraphic data from late Quaternary sediments from the Yermak Plateau, Arctic Ocean: Evidence for four geomagnetic polarity events within the last 170 ka of the Brunhes Chron, Geophys. J. Int., 117, 453–471, 1994.
Ortiz, J., A. Mix, S. Hostetler, and M. Kashgarian, The California current of the last glacial maximum: Reconstruction at 42 degrees N based on multiple proxies, Paleoceanography, 12, 191–205, 1997.
Petermann, H. and U. Bleil, Detection of live magnetotactic bacteria in South Atlantic deep-sea sediments, Earth Planet. Sci. Lett., 117, 223–228, 1993.
Roberts, A. P. and G. M. Turner, Diagenetic formation of ferrimagnetic iron sulfide minerals in rapidly deposited marine-sediments, South-Island, New-Zealand, Earth Planet. Sci. Lett., 115, 257–273, 1993.
Sancetta, C., M. Lyle, L. Heusser, R. Zahn, and J. P. Bradbury, Late-glacial to Holocene changes in winds, upwelling, and seasonal production of the Northern California current system, Quat. Res., 38, 359–370, 1992.
Soutar, A. and P. A. Crill, Sedimenation and climatic patterns in the Santa Barbara basin during the 19th and 20th centuries, Geol. Soc. Am. Bull., 88, 134–136, 1977.
Tarduno, J., Temporal trends of magnetic dissolution in the pelagic realm: gauging paleoproductivity?, Earth Planet. Sci. Lett., 123, 39–48, 1994.
Tauxe, L., J. L. LaBrecque, R. Dodson, and M. Fuller, U-channels-a new technique for paleomagnetic analysis of hydraulic piston cores, EOS Trans. AGU, 64, 219, 1983.
Tauxe, L., Sedimentary records of relative paleointensity of the geomagnetic field: theory and practice, Rev. Geophys., 31, 319–354, 1993.
Valet, J.-P. and L. Meynadier, Geomagnetic field intensity and reversals during the past four million years, Nature, 366, 234–238, 1993.
Weeks, R., C. Laj, L. Endignoux, M. Fuller, A. P. Roberts, R. Manganne, E. Blanchard, and W. Goree, 1993. Improvements in long-core measurement techniques: Applications in palaeomagnetism and palaeoceanography, Geophys. J. Int., 114, 651–662, 1993.
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Richter, C., Hayashida, A., Guyodo, Y. et al. Magnetic intensity loss and core diagenesis in long-core samples from the East Cortez Basin and the San Nicolas Basin (California Borderland). Earth Planet Sp 51, 329–336 (1999). https://doi.org/10.1186/BF03352237
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DOI: https://doi.org/10.1186/BF03352237