Skip to main content

Table 1 Paleomagnetic results from the Ryukyu Group in the Miyakojima Island (Anai et al. 2017)

From: Reductive chemical demagnetization: a new approach to magnetic cleaning and a case study of reef limestones

Unit

Site

Latitude (N)

Longitude (E)

Elevation (m)

Facies

NRM (mA/m)

N0 (all samples)

N (MAD < 15°)

D (°)

I (°)

α95 (°)

k

VGP

Area A

Area B

avarage

TD

RCD + AFD

Total

TD

RCD + AFD

Total

Latitude

Longitude

1

Q-4

24°42′35″

125°18′54″

 

3.0

R

1.10

6

4

10

1*

2

2

(132.6)

(− 31.0)

(10.7)

(550.4)

− 45.1

215.6

1

Q-28

24°44′42″

125°15′38″

4.5

 

R

0.725

8

5

13

1*

2

2

(186.7)

(− 40.3)

(60.3)

(19.4)

− 83.7

25.2

2

M-12

24°46′00″

125°17′03″

18.5

 

C

0.224

6

6

12

0

2

2

(196.6)

(− 34.2)

(18.3)

(188.4)

− 73.5

21.1

2

P-35

24°42′43″

125°19′08″

 

18.0

C

14.0

7

6

13

0

3

3

194.8

− 33.7

21.6

33.6

− 74.9

18.2

2

A-10

24°42′59″

125°18′38″

 

21.3

C

1.06

6

5

11

0

2

2

(144.5)

(− 29.7)

(57.2)

(2.5)

− 55.7

221.4

2

N-10

24°45′00″

125°17′30″

21.0

 

C

0.0765

7

5

12

0

2

2

(218.0)

(− 35.3)

(18.0)

(47.9)

− 54.5

34.9

2

P-16

24°43′09″

125°18′48″

 

24.5

C

0.306

7

7

14

0

3

3

187.0

− 32.1

31.8

16.0

− 80.4

1.2

3

P-23

24°43′13″

125°19′00″

 

27.5

R

0.0754

7

6

13

1

2

3

199.4

− 33.1

21.3

330.8

− 70.9

22.2

3

Q-43

24°44′11″

125°20′50″

 

31.0

R

0.867

7

5

12

0

2

2

(175.2)

(− 22.6)

(14.1)

(317.6)

− 76.5

93.9

3

Q-31

24°43′09″

125°20′30″

 

32.0

R

10.7

6

7

13

0

4

4

190.3

− 34.9

23.1

16.8

− 79.1

13.5

3

N-8

24°43′15″

125°17′54″

30.0

 

R

0.0752

6

6

12

2**

1

2

(178.5)

(− 33.8)

(52.8)

(24.5)

− 83.9

91.1

4

P-18

24°43′20″

125°18′55″

 

34.5

R

1.44

5

6

11

0

3

3

194.7

− 45.3

26.0

23.6

− 76.5

46.2

4

Q-31-2

24°43′20″

125°20′30″

 

36.5

R

0.368

7

5

12

2

0

2

(347.9)

(38.4)

(12.6)

(96.8)

78.0

25.5

4

Q-43-2

24°43′13″

125°20′50″

 

37.0

R

1.57

7

6

13

2

1

3

21.2

38.9

23.6

113.8

70.3

217.8

4

Dd-5

24°44′33″

125°18′02″

 

51.0

R

0.0976

6

2

8

4

0

4

358.7

47.6

4.6

399.9

85.6

88.4

4

Ee-10

24°44′13″

125°21′40″

 

70.5

R

0.954

6

2

8

3

0

3

354.7

35.5

11.6

114.6

83.1

0.4

5

Aa-18

24°47′21″

125°18′30″

49.5

 

C

2.35

5

3

8

2

1

3

351.1

37.4

21.8

32.9

81.0

17.4

5

Cc-17

24°45′37″

125°19′05″

54.0

 

C

0.235

6

0

6

4

0

4

354.8

33.2

5.2

168.2

82.0

354.7

5

Cc-13

24°45′47″

125°19′14″

63.0

 

C

0.873

6

2

8

3

0

3

9.0

36.0

35.8

12.9

80.5

236.9

5

Cc-14

24°45′46″

125°19′14″

65.0

 

C

0.463

6

0

6

5

0

5

347.0

31.9

20.9

14.3

75.9

12.2

  1. N0: number of specimens used to measurement paleomagnetic direction, the row of N0; TD: number of specimens treated with thermal demagnetization (TD), RCD + AFD: number of specimens treated with combination procedure reductive chemical demagnetization (RCD) and Alternating field demagnetization (AFD). N: number of specimens with MAD < 15°. D and I: declination and inclination of site mean direction, which is calculated from the specimens passed the criteria, respectively. α95: 95% confidence limit; k: precision parameter; facies of R and C: rhodolith limestone and coral-bioclastic-limestone, respectively. Parenthesis are reference value (n ≤ 2). *: these samples were not used to calculate a site mean palaeomagnetic direction. **: one sample was not used to calculate a site mean palaeomagnetic direction. These samples gave inconsistent directions