Unit 5

Question 1

What features in a crush-rock sample that may indicate it was salted with river gold?

Answer 1

-no signs of host rock
-shape indicative of move water (smooth, flat or rounded, spherical)
-purity (high for river gold)

Question 2

Name some ways to differentiate a diamond from a cubic zirconia.

Answer 2

Diamond tester, thermal conductivity tester, x-ray diffraction, refractometer, heat test, scratch test, density test, visual test (UV, color, florescence).

Or look for laser markings and serial number.

Question 3

Why is the testing of white paint on paintings significant in forensic analysis?

Answer 3

the record of varying materials used to create pigments throughout history

Question 4

Name some different materials used to create white pigments throughout history.

Answer 4

Chalk, lead, zinc, titanium

Question 5

How can an explosion be identified based on short and long wave seismic energy?

Answer 5

Explosions have lower energies at long wavelengths and higher energies at short wavelengths. There ratios are usually above 1.0

Question 5

What material do caves form in?

Answer 5

Limestone

Question 5

How can an earthquake be identified based on short and long wave seismic energy?

Answer 5

Earthquakes have higher energies at long wavelengths and shorter energies at short wavelengths. There ratios are usually below 1.0

Question 6

Describe Quaternary alluvium.

Answer 6

Poorly sorted geological deposit formed during the Quaternary period.

Question 7

What is an isotope?

Answer 7

Element with the same number of protons but different numbers of neutrons resulting in different atomic weights.

Question 8

How are isotopes detected?

Answer 8

Through isotopic analysis using a mass spectrometer

Question 9

What is the Rb-Sr decay system?

Answer 9

A geochemical tracer

1/4 isotopes for Strontium, (87Sr) is produced through radioactive decay of rubidium isotope (87Rb). Anything that originally contained Rb will have increasing levels of 87Sr.

Question 10

How does the Rb-Sr decay system help us understand the movements of past individuals through time?

Answer 10

Sr can substitute for calcium during the formation of bone, dentine, and enamel
Different Sr values are found in different geologic areas.
Varying Sr levels can be found in a persons remains based on when and where the Sr was stored (close to water vs inland, Sr value from dentine, enamel or bone)

Question 11

When is enamel formed?

Answer 11

the first 4-12 years of life and doesn’t change after that

Question 12

When is bone formed?

Answer 12

throughout an persons life

Question 13

What does different Sr levels in a person enamel vs bone indicate?

Answer 13

They moved at some point in their life

Question 14

How are “local” Sr isotope ratios obtained?

Answer 14

Comparing Sr levels in local proxies (e.g. local animals)

Question 15

How could you assess human mobility from a tooth sample?

Answer 15

By extracting a purified Sr sample and comparing it to a living and deceased proxy animal from the area. If its different, the sample if from a different area.

Question 16

What 4 steps are important in investigating a potential contamination?

Answer 16

1. Information gathering
2. Testing, sampling, analysis
3. Hazard/risk analysis and mitigation
4. Findings and recommendations

Question 17

How is potential contamination of ground water and wetlands assessed?

Answer 17

-the analysis of molecular containment trace elements both regularly and ongoing through monitoring wells, ground and surface samples

Question 18

How would you test potential contamination of a water supply?

Answer 18

routine monitoring of river water (up and down stream), the water supply plant, the supply plant intake system, and monitoring wells