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Riisager et al. 2003
Riisager, J., Riisager, P. and Pedersen, A.K. (2003). The C27n-C26r geomagnetic polarity reversal recorded in the west Greenland flood basalt province: How complex is the transitional field?. Journal of Geophysical Research 108: doi: 10.1029/2002JB002124. issn: 0148-0227.

We present a paleomagnetic record of the C27n-C26r (~60.9 Ma) geomagnetic polarity reversal (GPR) sampled in two separate lava sequences in the Vaigat Formation, west Greenland flood basalt province. The two profiles, distanced 16 km apart, consist of 45 and 35 sampled lava flows of which 31 and 23, respectively, record transitional field directions. A prominent feature of each profile is the presence of successive flows with similar paleomagnetic directions, which based on geological, geochemical, and paleomagnetic evidences are interpreted to represent flow fields (i.e., lavas erupted in a short period of time) rather than periods when the geomagnetic field stood still. Multimodel photogrammetry shows that the typical flow length of Vaigat Formation picritic lavas is <2 km, which explains why flow-to-flow correlation of paleomagnetic directions between the two profiles (16 km apart) is not possible. The two profiles therefore record different and independent time series of the same GPR, allowing us to cast light on some of the questions that have arisen from single records. Particularly noteworthy is the fact that the two high-resolution paleomagnetic records share no general trends, clearly indicating that the C27n-C26r transitional field was more complex and faster changing than can be resolved by either record. In addition, we obtained stable polarity paleomagnetic data from both pretransitional C27n and posttransitional C26r yielding a paleomagnetic pole latitude 64.8¿N, longitude 141.5¿E (N = 14, K = 19.8, A95 = 9.2¿) that passes reversal test.

BACKGROUND DATA FILES

Abstract

Keywords
Geodesy and Gravity, Photogrammetry, Geomagnetism and Paleomagnetism, Rapid time variations, Geomagnetism and Paleomagnetism, Reversals (process, timescale, magnetostratigraphy), Information Related to Geologic Time, Cenozoic
Journal
Journal of Geophysical Research
http://www.agu.org/journals/jb/
Publisher
American Geophysical Union
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