Mapping Glacial Striations

The map at the left shows the location of a series of glacially polished and striated rock outcrops along Fairfield Avenue.

1. 1.  locate the rocks and observe their smooth surface, locate the scratches on the surface.

2.  using your compass, measure the orientation of these scratches as practiced during our first lab exercise.

There are a few things to consider:

a)  the rocks are pretty magnetic, so keep your compass away from the rocks

b)  did you set the proper declination ?  the declination in Hartford is approximately 14 degrees West. Make sure you set your compass properly.  Fairfield Ave. runs almost N-S. That's a good way to check your declination setting.

c)  it is best to stand directly over the striations and sight along the edge of the compass, lining up the striations with the edge of the plastic baseplate. line up the needle with the double arrow on the baseplate (which now points 14 degrees to the west) and read off the orientation of the scratch from the white North-mark.

3.  repeat this measurement for 10 to 20 striations.

4. what is the average orientation of the scratches? What can you say about glacial movement in the CT valley?

What to turn in:

a)  your raw data (orientation measurements)

b) a brief paragraph explaining your results and your interpretation of the data

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