|
Core, section, interval (cm)
|
Depth (mbsf)
|
Principal component analysis
|
Stable endpoint
|
Angular distance (°)
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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Inclination (°)
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Declination (°)
|
MAD
(°) |
Length
(A/m)
|
Deviation (°)
|
Number
of steps |
Lowest step (mT)
|
Highest step (mT)
|
Inclination (°)
|
Declination (°)
|
k
|
N
|
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| 206-1256A- |
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| 1H-1, 22.5 | 0.225 | 43.9 | 12.6 | 16.5 | 1.01E-02 | 26.9 | 3 | 15 | 25 | 18.1 | 3.3 | 821.4 | 3 | 27.0 |
| 1H-1, 25.0 | 0.250 | 44.3 | 40.3 | 21.6 | 8.65E-03 | 36.2 | 3 | 15 | 25 | 17.6 | 11.0 | 567.0 | 3 | 36.3 |
| 1H-1, 27.5 | 0.275 | 46.7 | 51.4 | 25.8 | 7.48E-03 | 43.7 | 3 | 15 | 25 | 17.8 | 11.2 | 475.9 | 3 | 43.8 |
| 1H-1, 30.0 | 0.300 | 49.2 | 50.5 | 27.1 | 6.80E-03 | 46.0 | 3 | 15 | 25 | 17.4 | 9.0 | 485.4 | 3 | 46.1 |
| 1H-1, 32.5 | 0.325 | 51.5 | 54.9 | 28.8 | 6.20E-03 | 50.4 | 3 | 15 | 25 | 16.5 | 8.8 | 473.2 | 3 | 50.5 |
| 1H-1, 35.0 | 0.350 | 50.7 | 61.1 | 28.4 | 6.07E-03 | 53.3 | 3 | 15 | 25 | 15.7 | 10.6 | 429.1 | 3 | 53.3 |
| 1H-1, 37.5 | 0.375 | 51.5 | 69.7 | 28.6 | 6.08E-03 | 57.2 | 3 | 15 | 25 | 16.1 | 12.5 | 378.9 | 3 | 57.2 |
| 1H-1, 40.0 | 0.400 | 53.9 | 68.5 | 27.9 | 6.03E-03 | 57.0 | 3 | 15 | 25 | 16.8 | 11.8 | 376.3 | 3 | 57.1 |
| 1H-1, 42.5 | 0.425 | 58.3 | 64.3 | 28.8 | 5.71E-03 | 57.5 | 3 | 15 | 25 | 17.1 | 9.0 | 389.1 | 3 | 57.6 |
| 1H-1, 45.0 | 0.450 | 57.7 | 48.7 | 29.2 | 5.65E-03 | 51.8 | 3 | 15 | 25 | 16.4 | 6.4 | 408.2 | 3 | 51.8 |
| 1H-1, 47.5 | 0.475 | 48.1 | 33.4 | 25.0 | 6.11E-03 | 39.7 | 3 | 15 | 25 | 14.9 | 6.7 | 496.0 | 3 | 39.8 |
| 1H-1, 50.0 | 0.500 | 41.8 | 33.2 | 19.8 | 7.04E-03 | 34.0 | 3 | 15 | 25 | 14.7 | 9.2 | 567.1 | 3 | 34.1 |
| 1H-1, 52.5 | 0.525 | 39.4 | 33.2 | 16.4 | 8.07E-03 | 30.5 | 3 | 15 | 25 | 15.6 | 11.2 | 601.1 | 3 | 30.6 |
| 1H-1, 55.0 | 0.550 | 39.7 | 30.4 | 14.7 | 8.54E-03 | 28.5 | 3 | 15 | 25 | 16.4 | 11.3 | 624.2 | 3 | 28.6 |
| 1H-1, 57.5 | 0.575 | 39.7 | 28.0 | 15.2 | 8.50E-03 | 28.2 | 3 | 15 | 25 | 16.0 | 10.2 | 619.7 | 3 | 28.3 |
| 1H-1, 60.0 | 0.600 | 41.9 | 26.2 | 17.0 | 7.98E-03 | 30.0 | 3 | 15 | 25 | 16.0 | 8.3 | 601.8 | 3 | 30.2 |
| 1H-1, 62.5 | 0.625 | 44.5 | 20.5 | 17.8 | 7.57E-03 | 30.1 | 3 | 15 | 25 | 16.9 | 5.7 | 662.6 | 3 | 30.3 |
| 1H-1, 65.0 | 0.650 | 43.5 | 30.8 | 17.4 | 7.91E-03 | 31.1 | 3 | 15 | 25 | 18.9 | 7.8 | 600.1 | 3 | 31.2 |
| 1H-1, 67.5 | 0.675 | 41.3 | 37.8 | 14.9 | 9.39E-03 | 29.9 | 3 | 15 | 25 | 21.4 | 11.2 | 541.4 | 3 | 30.1 |
| 1H-1, 70.0 | 0.700 | 41.0 | 33.3 | 10.5 | 1.17E-02 | 25.9 | 3 | 15 | 25 | 22.6 | 11.2 | 653.6 | 3 | 26.1 |
| 1H-1, 72.5 | 0.725 | 40.0 | 18.3 | 6.6 | 1.35E-02 | 20.9 | 3 | 15 | 25 | 21.8 | 6.1 | 1126.6 | 3 | 21.0 |
| 1H-1, 75.0 | 0.750 | 38.0 | 10.4 | 4.0 | 1.47E-02 | 18.8 | 3 | 15 | 25 | 20.3 | 2.5 | 1542.9 | 3 | 19.0 |
| 1H-1, 77.5 | 0.775 | 36.7 | 5.5 | 3.0 | 1.49E-02 | 18.7 | 3 | 15 | 25 | 18.7 | 359.7 | 1675.7 | 3 | 18.8 |
| 1H-1, 80.0 | 0.800 | 33.4 | 6.2 | 2.8 | 1.51E-02 | 18.3 | 3 | 15 | 25 | 16.1 | 359.0 | 1727.5 | 3 | 18.4 |
| 1H-1, 82.5 | 0.825 | 27.6 | 7.7 | 2.3 | 1.66E-02 | 16.3 | 3 | 15 | 25 | 13.1 | 359.3 | 1984.1 | 3 | 16.4 |
| 1H-1, 85.0 | 0.850 | 24.9 | 8.4 | 2.3 | 1.89E-02 | 15.4 | 3 | 15 | 25 | 11.8 | 359.5 | 1888.9 | 3 | 15.6 |
| 1H-1, 87.5 | 0.875 | 27.2 | 7.2 | 2.5 | 1.93E-02 | 16.6 | 3 | 15 | 25 | 12.3 | 359.1 | 1339.6 | 3 | 16.7 |
| 1H-1, 90.0 | 0.900 | 34.7 | 4.6 | 2.7 | 1.71E-02 | 20.6 | 3 | 15 | 25 | 14.6 | 358.5 | 865.7 | 3 | 20.8 |
| 1H-1, 92.5 | 0.925 | 36.7 | 0.6 | 1.8 | 1.65E-02 | 20.5 | 3 | 15 | 25 | 16.1 | 358.4 | 995.2 | 3 | 20.7 |
| 1H-1, 95.0 | 0.950 | 29.9 | 357.4 | 0.6 | 1.85E-02 | 15.5 | 3 | 15 | 25 | 14.2 | 358.1 | 1965.0 | 3 | 15.7 |
Notes: The mean paleomagnetic direction is estimated from the demagnetization data using the principal component analysis (PCA) method of Kirschvink (1980). The best-fit line that passes through the vector demagnetization data is not forced to be anchored to the origin of vector demagnetization space but is allowed to freely fit the data. To avoid data possibly contaminated by the drilling overprint, we do not use demagnetization steps <20 mT for all sections except 206-1256A-1H-1 and 206-1256B-1H-1, where the 15-mT step was used. We use an iterative search program to find and delete demagnetization steps in any interval that give directions that are outliers relative to directions from other demagnetization steps from that interval. The declinations have been reoriented to geographic north. PCA parameters, in addition to the direction (inclination and declination), are MAD = maximum angular deviation, length = distance from origin of the vector demagnetization space to the centroid of the data used to find the best-fit line, deviation angle = the angle between the best-fit line and a line that passes through the origin and centroid, number of steps = number of demagnetization steps used in finding the best-fit line, lowest step = the lowest demagnetization step used in finding the best-fit line, highest step = the highest demagnetization step used in finding the best-fit line. For comparison, we also compute a Fisherian mean of the highest three or four demagnetization steps for each interval. This is referred to as the stable endpoint direction. Typically, only the highest three demagnetization steps are used in the average, unless the mean of these three directions has a dispersion parameter <200, in which case the fourth highest demagnetization step is included. When the dispersion parameter is <200, we also use an iterative search to find and remove the direction that is the largest outlier. Stable endpoint parameters, in addition to the mean direction (inclination and declination), are k = the Fisherian dispersion parameter, N = the number of directions from the three highest demagnetization steps that were averaged, angular distance = the angular distance between the PCA direction and the stable endpoint direction. Only a portion of this table appears here. The complete table is available in ASCII.