Stereonet Plotting planes and lines. Boris Natalin

Transcription

1 Stereonet Plotting planes and lines Boris Natalin

2 Conventional lettering on stereonet

3 My lettering (on the stereonet) 90 27

4 Lettering on the overlay Use marks that are shown by red

5 Plotting plane Plotting: 1) Rotate the overlay to the mark that correspond to 55º Dip direction and dip angle of bedding

6 Plotting plane 2) Keep the overlay in this position 3) Plot the plane and pole on the overlay (blue) Great circle

7 4) Check plotting rotating the overlay to the initial position. Done!

8 Plotting a line Plotting: 1) Rotate the overlay to the mark that correspond to 50º

9 Plotting a line 2) Keep the overlay in this position 3) Plot the line on the overlay (blue dot)

10 4) Check plotting rotating the overlay to the initial position. Done!

11 Small circles

12 Rotation about vertical axis Trace of the rotation of a line about vertical axis (Fig. a) makes small circle

13 Rotate a line 60/30 clockwise for 45º Red mark Red mark

14 Rotate a line 60/30 clockwise for 45º Plotting the line: 1) Rotate red mark on the overlay to plunge direction of 60º 2) Plot the line counting 30º from the periphery of stereonet

15 3) Keep the position of the overlay 4) Visualize clockwise rotation for 45º 5) Plot a blue mark onto the overlay, which is the plunge direction after rotation Vertical axis Rotate a line 60/30 clockwise for 45º blue mark

16 6) Rotate the blue mark to the horizontal diameter of the stereonet Rotate a line 60/30 clockwise for 45º

17 7) Plot the line counting 30. Rotation about the vertical axis does not change the plunge! Rotate a line 60/30 clockwise for 45º

18 Line is rotated!

19 Clockwise rotation of the plane 60/30 about the vertical axis for 45º 1) Plot the plane rotating red mark to 60º

20 2) Keep the position of the overlay 3) Visualize clockwise rotation for 45º 4) Plot a blue mark onto the overlay either for the new plunge direction of the pole or for the strike line Clockwise rotation of the plane 60/30 about the vertical axis for 45º

21 The new plunge direction of the pole is used. 5) Rotate it to the horizontal diameter 6) Plot the new pole (red). Rotation about the vertical axis does not change its plunge! 7) Plot the new plane (red) Clockwise rotation of the plane 60/30 about the vertical axis for 45º

22 Rotation is done! Clockwise rotation of the plane 60/30 about the vertical axis for 45º

23 Examine the results

24 Where horizontal axis is? Where vertical diameter of stereonet is? 1) Plot the line

25 2) Visualize the problem. The axis of the rotation is vertical diameter of stereonet. Clockwise rotation should be about the northern end of this axis. 3) Count 45º along the small circle in the proper direction. 4) Plot the rotated line (red). The problem is solved!

26 1) Plot the plane 60/30 plane 60/30

27 2) Visualize the problem. The axis of the rotation is vertical diameter of stereonet. Clockwise rotation should be about the northern end of this axis. 3) For the pole (blue dot) count 45º along the small circle in the proper direction. 4) Plot the rotated pole (red dot). plane 60/30

28 5) Rotate the overlay until the new (rotated) pole (red dot) occur on the horizontal diameter. plane 60/30

29 6) Plot the plane for the rotated pole plane 60/30

30 plane 60/30 7) Rotate the overlay in the initial position. The problem is solved!!

31 Rotation about axis of any orientation Red mark on overlay Plunge direction 245º

32 Plotting the axis of rotation, which is determined 245

33 Plotting the line, which we will rotate

34 Checking

35 Rotation is counterclockwise Rotations about vertical or horizontal axis are simple We will use both of them

36 Move the determined axis of rotation to horizontal diameter (rotate overlay) Then use vertical diameter as the axis of rotation and move blue mark to the periphery of stereonet (33º) Move the line in the same direction along the small circle for 33º

37 Rotate stereonet about the vertical axis for 90º In this position, the vertical diameter of stereonet coincide with the determined axis of rotation

38 Rotate the line for 45º (move red mark along the small circle in accord with the sense of rotation)

39 Rotate stereonet back for 90º about the vertical axis (blue mark must be on the horizontal diameter) Use horizontal axis (vertical diameter) to rotate the determined axis of the rotation to its original position The line should also be rotated (move red mark for 33º)

40 Return stereonet to the initial position Rotation is done

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