SO461, Geological Oceanography

 Magnetic Anomalies Lab, Fall 2008

   

You may complete question #1 in groups.  Question #2 will be turned in for a grade, and will be individual work.

1.  This diagram shows three marine magnetic anomaly profiles.  The distance scale is given at the top and bottom, and marine magnetic anomaly scale for the past 10 Ma (black normal) is on the bottom.

 Explain, by referring to the diagram:

 

 



2.  This diagram shows three east-west magnetic profiles across a suspected ridge that runs north-south.  All have the same scale.  A magnetic anomaly scale at the bottom shows the times of the anomalies for the past 13 Ma.

 

 


Table 1.  Cande and Kent Geomagnetic Time Scale

Top (Ma)

Base (Ma)

NORMAL interval

NAME

0.000

0.780

1n

Brunhes/Matuyama

0.990

1.070

1r.1n

Jaramillo

1.770

1.950

2n

Olduvai

2.140

2.150

2r.1n

 

2.581

3.040

2An.1n

Matuyama/Gauss

3.110

3.220

2An.2n

 

3.330

3.580

2An.3n

Gauss/Gilbert

4.180

4.290

3n.1n

Cochiti

4.480

4.620

3n.2n

Nunivak

4.800

4.890

3n.3n

Sidufjall

4.980

5.230

3n.4n

Thvera

5.894

6.137

3An.1n

 

6.269

6.567

3An.2n

 

6.935

7.091

3Bn

 

7.135

7.170

3Br.1n

 

7.341

7.375

3Br.2n

 

7.432

7.562

4n.1n

 

7.650

8.072

4n.2n

 

8.225

8.257

4r.1n

 

     8.699

9.025

4An

 

9.230

9.308

4Ar.1n

 

9.580

9.642

4Ar.2n

 

9.740

9.880

5n.1n

 

9.920

10.949

5n.2n

 

11.052

11.099

5r.1n

 

11.476

11.531

5r.2n

 

11.935

12.078

5An.1n

 

12.184

12.401

5An.2n

 

12.678

12.708

5Ar.1n

 

12.775

12.819

5Ar.2n

 

12.991

13.139

5AAn

 

13.302

13.510

5ABn

 

13.703

14.076

5ACn

 

14.178

14.612

5ADn

 

14.800

14.888

5Bn.1n

 

15.034

15.155

5Bn.2n

 

16.014

16.293

5Cn.1n

 

16.327

16.488

5Cn.2n

 

16.556

16.726

5Cn.3n

 

17.277

17.615

5Dn

 

18.281

18.781

5En

 

19.048

20.131

6n

 

 


Additional problems :