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Earth, Planets and Space

Table 2 Summary of results of the Tsunakawa–Shaw API experiments

From: Paleomagnetic study of basaltic rocks from Baengnyeong Island, Korea: efficiency of the Tsunakawa–Shaw paleointensity determination on non-SD-bearing materials and implication for the early Pliocene geomagnetic field intensity

Specimen

NRMLTD,0 (Am2/kg)

ARM00 (Am2/kg)

MDFA0 (mT)

LTDA00 (%)

NRM

First heating

Second heating

Blab (μT)

Banc (μT)

HL (mT)

HH (mT)

D (°)

I (°)

MADfree (°)

HL (mT)

HH (mT)

SlopeA0

SlopeN

fN

rN

HL (mT)

HH (mT)

SlopeA1

SlopeT

fT

rT

B1A-1-1

8.63E–04

1.17E–03

28

17

8

180

nd

nd

1.6

8

180

0.936

0.397

0.926

0.998

0

180

0.993

0.976

0.989

1.000

30.0

11.9

B1A-2-1

9.51E–04

1.11E–03

27

19

18

140

350.1

39.2

0.9

18

60

0.841

0.591

0.596

0.999

0

180

0.991

0.989

0.991

1.000

20.0

11.8

B1B-1-1

9.80E–04

1.41E–03

31

14

4

180

nd

nd

1.0

4

180

0.942

0.385

0.969

0.997

0

180

0.999

1.029

0.989

0.999

30.0

11.6

B1B-2-1

8.66E–04

1.27E–03

30

13

2

140

353.7

45.7

1.1

2

140

0.909

0.566

0.986

0.997

0

180

1.013

0.988

0.989

1.000

20.0

11.3

B1D-1-1

7.11E–04

8.90E–04

25

24

20

180

nd

nd

2.3

20

180

0.829

0.977

0.624

0.995

0

180

0.989

1.000

0.985

0.999

15.0

14.7

B1D-2-1

8.00E–04

8.93E–04

26

23

10

140

115.6

− 77.0

1.2

10

140

0.852

0.665

0.896

0.998

0

180

1.013

0.973

0.990

1.000

20.0

13.3

B1E-1-1

9.08E–04

9.52E–04

29

20

10

180

nd

nd

1.0

10

180

0.869

0.861

0.928

0.998

0

180

0.987

1.003

0.993

1.000

15.0

12.9

B1E-2-1

5.42E–04

8.72E–04

28

21

10

140

351.0

42.6

0.9

10

140

0.842

0.589

0.902

0.998

0

180

1.004

0.990

0.989

1.000

20.0

11.8

B1G-1-1

8.53E–04

1.04E–03

28

20

10

180

nd

nd

1.4

10

180

0.878

0.947

0.902

0.996

0

180

0.998

1.005

0.989

1.000

15.0

14.2

B1G-2-1

6.59E–04

1.03E–03

28

21

10

140

355.9

29.3

0.9

10

140

0.902

0.611

0.883

0.996

0

180

0.981

1.021

0.988

1.000

20.0

12.2

B2B-1-1

3.79E–04

1.60E–03

29

21

20

180

nd

nd

7.5

20

180

0.791

0.210

0.655

0.985

0

180

0.982

1.136

0.977

0.999

15.0

nd

B2B-2-1

5.96E–04

1.57E–03

23

20

22

140

nd

nd

8.2

22

140

0.724

0.179

0.599

0.991

0

180

1.000

1.130

0.974

0.999

20.0

nd

B2C-1-1

9.65E–04

1.63E–03

31

11

22

180

nd

nd

1.7

22

180

0.753

1.055

0.721

0.998

0

180

0.978

1.027

0.985

0.999

15.0

15.8

B2C-2-1

9.64E–04

9.64E–04

28

13

14

140

344.4

37.1

1.0

14

140

0.813

0.797

0.884

0.999

0

180

0.973

1.023

0.990

0.999

20.0

15.9

B2D-2-1

1.70E–04

1.38E–03

26

23

10

140

336.3

29.9

3.6

10

140

0.578

0.222

0.907

0.979

0

180

0.996

1.091

0.983

1.000

20.0

nd

B2E–1-1

3.79E–04

1.53E–03

25

23

16

180

nd

nd

6.1

16

180

0.562

0.239

0.669

0.988

0

180

0.994

1.075

0.970

0.999

15.0

nd

B2E–2-1

2.31E–04

1.38E–03

20

24

12

140

339.3

37.9

5.5

12

140

0.527

0.168

0.701

0.978

0

180

1.002

1.069

0.975

0.999

20.0

nd

B2F-1-1

3.11E–04

1.56E–03

23

16

14

180

nd

nd

6.2

14

180

0.560

0.219

0.644

0.995

2

180

1.016

1.038

0.978

0.999

15.0

3.29

B2F-2-1

2.87E–04

1.40E–03

19

22

20

140

344.8

39.9

5.1

20

140

0.525

0.179

0.587

0.989

0

180

0.993

1.041

0.980

0.999

20.0

nd

B2G-1-1

5.31E–04

1.44E–03

30

23

12

180

nd

nd

4.5

12

180

0.619

0.359

0.918

0.976

0

180

0.987

1.131

0.973

0.999

15.0

nd

B2G-2-1

4.36E–04

1.39E–03

24

23

20

140

351.1

41.3

5.9

20

140

0.623

0.203

0.602

0.996

0

180

0.984

1.139

0.983

1.000

20.0

nd

                   

N

Mean ± SD (µT)

                  

B1 site mean

10

12.6 ± 1.2

                  

B2 site mean

3

11.7 ± 7.3

                  

B2 site mean#

2

15.9 ± 0.1

                  

Overall mean

13

12.4 ± 3.2

                  

Overall mean#

12

13.1 ± 1.7

  1. NRMLTD,0, intensity after LTD for NRM. ARM00, intensity after LTD for ARM0. MDFA0, median destructive field of ARM0 in progressive AFD. LTDA00, LT demagnetized fraction of ARM0, expressed as (ARM0 intensity after LTD)/(ARM0 intensity before LTD) × 100. HL, HH, low (high) limit of the interval of AF steps chosen for the determination of a characteristic direction or a linear segment. D, I, MADfree, declination and inclination in the geographic coordinate system and the maximum angular deviation determined by the PCA free-floating fit (Kirschvink 1980) for the chosen intervals of data. Time, hold time at the set peak temperature (610 °C) in each heating process. The slopeA0, slopeA1, and slope values determined from all data points after LTD in each of the ARM0-ARM1 and ARM1-ARM2 diagrams. The slopeN, slopeT, slope values of the chosen linear segment in each of the NRM-TRM1* and TRM1-TRM2* diagrams. The fN, fT, NRM, and TRM1 fractions of the chosen linear NRM-TRM1* and TRM1-TRM2* segments. The rN, rT, correlation coefficients for linearity of the chosen linear segment of NRM/TRM1* and TRM1/TRM2* data points, respectively. Blab, laboratory DC field during the TRM1 and TRM2 acquisitions. Banc, API estimate
  2. “nd” denotes “not determined”. Arabic numerals with bold italic denote the values failing to meet the corresponding selection criterion. In the bottom of the table, site means and overall means of API estimates are listed
  3. The mean value with # mark is calculated from all other specimen-level estimates excluding one for specimen B2F-1-1 (3.29 μT)
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