Results 161 to 170 of about 519 (182)
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Geomagnetic Paleosecular Variation During the Early Cretaceous
19th Congress of the Brazilian Geophysical Society - ProceedingsIn this study, the amplitude of secular geomagnetic variation is investigated using directional paleomagnetic data obtained from rock samples collected in geological sections of the Paraná Basin.
Everton Frigo +3 more
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The Holocene paleosecular variation record from Elk Lake, Minnesota
Journal of Geophysical Research: Solid Earth, 1989The paleosecular variation record of the geomagnetic field from Elk Lake, Minnesota, is presented and its implications are discussed. The Elk Lake record is compiled from measurements of four parallel cores with a 2 cm sampling interval (≈15 years).
Donald R. Sprowl, Subir K. Banerjee
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Correcting distorted paleosecular variation in late glacial lacustrine clay
Physics of the Earth and Planetary Interiors, 2008Abstract An undisturbed, horizontal chronostratigraphic marker horizon of laminated red glacio-lacustrine clay crops out over ∼25,000 km 2 in northern Ontario, Canada. The primary, clastic hematite laminae possess two stable vector components of magnetization. We sampled a 1.6 m vertical section at overlapping 2 cm intervals in cubic specimens (8 cm
G.J. Borradaile, B.S. Almqvist
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Paleosecular variation of the Honolulu Volcanic Series, Oahu, Hawaii
Journal of Geophysical Research, 1972A paleomagnetic study of 193 sample cores drilled from 25 sites (lava flows) in the Honolulu volcanic series exposed on SE Oahu, Hawaii, yielded a mean angular standard deviation of 9.4°, with 95% confidence limits between about 7.7° and 11.9°. Thus, these lavas in the Brunhes normal polarity epoch confirm an earlier low value for paleosecular ...
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Archaeo‐ and paleosecular variation, and long‐term asymmetries of the geomagnetic field
Reviews of Geophysics, 1983This report summarizes progress made during the last four years in (i) obtaining records of the geomagnetic secular variation using paleomagnetic techniques, (ii) analysis and modelling of the secular variation, and (iii) the study of asymmetries in the time‐averaged field: seen both as departures from the geocentric axial dipole model, and as ...
Charles E. Barton, Robert T. Merrill
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Paleosecular variations of the geomagnetic field during the Holocene from Eastern Asia
Physics of the Earth and Planetary Interiors, 2016Abstract High-resolution paleomagnetic secular variation (PSV) records bear great information of dynamics processes of the Earth’s geomagnetic field, and can be further used for inter-profile correlation and for dating sediments. However, effects of changes in the depositional environment on PSV records have not been fully determined.
Xiaoqiang Yang +7 more
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Science, 1996
The statistical characteristics of the local magnetic field of Earth during paleosecular variation, excursions, and reversals are described on the basis of a database that gathers the cleaned mean direction and average remanent intensity of 2741 lava flows that have erupted over the last 20 million years.
Camps, Pierre, Prévot, Michel
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The statistical characteristics of the local magnetic field of Earth during paleosecular variation, excursions, and reversals are described on the basis of a database that gathers the cleaned mean direction and average remanent intensity of 2741 lava flows that have erupted over the last 20 million years.
Camps, Pierre, Prévot, Michel
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Earth-Science Reviews, 1976
Abstract The percentage of normal and reversed magnetization in land-based paleomagnetic studies of Phanerozoic rocks (0 to − 570 m.y.) have been compiled in order to determine the long-term variation in polarity bias of the geomagnetic field. Where possible the results are compared with the record from marine magnetic anomalies. Only rarely is there
E IRVING, G PULLAIAH
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Abstract The percentage of normal and reversed magnetization in land-based paleomagnetic studies of Phanerozoic rocks (0 to − 570 m.y.) have been compiled in order to determine the long-term variation in polarity bias of the geomagnetic field. Where possible the results are compared with the record from marine magnetic anomalies. Only rarely is there
E IRVING, G PULLAIAH
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Comments on ‘A new method to determine paleosecular variation’ by D. Vandamme
Physics of the Earth and Planetary Interiors, 1997The method developed by Vandamme (1994, Phys. Earth Planet. Inter., 85: 131–142) for the selection of the virtual geomagnetic pole (VGP) data set in terms of an optimum cutoff angle derived from analyses of synthetic VGP populations is applied to three Brunhes VGP data sets from central Mexico.
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Russian Geology and Geophysics, 1993
A technique is described, which is aimed at determining the optimal number of specimens at sampling levels for a given volume of collection. Two main parameters are shown to be necessary for the calculations: a square of a paleosecular variation-to-intrastratal scattering amplitude ratio, Q, and an excess of secular variation amplitude distribution, γ2.
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A technique is described, which is aimed at determining the optimal number of specimens at sampling levels for a given volume of collection. Two main parameters are shown to be necessary for the calculations: a square of a paleosecular variation-to-intrastratal scattering amplitude ratio, Q, and an excess of secular variation amplitude distribution, γ2.
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