Undersøgelsesmetoder

Question 1

Grain size distribution

Answer 1

Is it clay, silt, sand or gravel.
Longer the travel the finer and more mixed material.
Short distance will give more local material

Question 2

Erratic boulders and indicator clasts

Question 3

Fine gravel and coarse sand (?)

Answer 3

Give the same answer as indicator clasts.

300 grains categorised
Not much material needed - statistically useful

Upper part of till more weathered

Question 4

Clast morphology

Answer 4

The roundness
Indicator of how it was transported.

Compared to similar types of clasts

Question 5

Heavy minerals

Answer 5

(Relative age - how easily they weather )
Source area - Composition

Question 6

Clay minerals

Answer 6

Only made by chemical weathering.
Origin and movement - best short transportation

(Clays can transform into other - indicate age)

Question 7

Geochemistry

Answer 7

Hard rock
Signature geochemistry

Question 8

Micromorphology

Answer 8

Microstructures - deformations ect.
Determine the environment

Different environments can give same structures

Question 9

Magnetic susceptibility

Answer 9

Good for matching tills over long distances.

Magnetic alignment with the direction of the transport (elongated) - easy to measure like this
Also in boreholes

Question 10

Geophysical investigations

Answer 10

Type of lithology.
(seismic profiles - TEM, borehole profiles - gamma and resistivity)