Layer

Thickness (cm)

Number of pebbles

Long axis (cm)

Short axis (cm)

Gravel layer

90

20

8.3

11.5

12.5

7.5

7.3

12.0

11.5

5.9

8.8

9.2

8.0

8.3

8.3

11.9

5.5

4.5

4.8

5.0

2.0

2.1

5.7

9.0

6.1

6.0

6.7

9.0

7.0

4.7

7.0

7.5

3.7

7.0

5.6

7.0

4.2

4.2

2.8

2.7

1.0

0.6