Earth Systems 3209

1. Earth Systems 3209 Reference: Chapters 21; Appendix A & B Unit: 5Earth’s Resources

2. Unit 5: Topic 2.2 Exploration Techniques Focus on . . . • identifying different exploration techniques used in industry.

3. Exploration Techniques • It should be noted that these exploration techniques should only be listed for the purpose of student awareness. • Some techniques will be covered extensively in the core laboratories and STSE.

4. Exploration Techniques • Remote Sensing • the collection and interpretation of information about an object without physical contact with the object; eg, satellite imaging and aerial photography. • Geological Mapping • a geological map is a special-purpose map made to show geological features. Rock units are shown by color or symbols to indicate where they are exposed at the surface. • Geochemical Surveys • the presence of some chemical elements may indicate the presence of a certain mineral. Chemical analysis of rocks may indicate the presence of an underground deposit. For instance elements like arsenic and antimony are associated with gold deposits.

5. Exploration Techniques • Bulk Sampling • is the removing of large mineralized rock that is selected to be representative of the potential ore body, in order to do mineral processing tests. • Observing Drill Cores • involves inspecting and analyzing drill core by different techniques and equipment depending on the type of data desired. • Prospecting • is a small-scale form of mineral exploration which is an organised, large scale effort undertaken by commercial mineral companies to find commercially viable ore deposits.

6. Exploration Techniques • Cross-Sections • provide a two-dimensional slice of Earth's subsurface and is used to help understand geologic conditions that occur in specific areas of the cross section. • Magnetic Survey • as the aircraft flies, the magnetometer records tiny variations in the intensity of the ambient magnetic field. This information is used to produce an aeromagnetic map showing the spatial distribution and relative abundance of magnetic in the upper levels of the crust. • Gravity Survey • involves looking at the subsurface structure based on the differences in densities of the subsurface rocks.

7. Helicopter Bush Cable “Bird” Exploration Techniques – Airborne Geophysics

8. Example 1: Which is an exploration technique? (A) Cracking (B) Floatation (C) Reforming (D) Prospecting Which exploration technique is based on density anomalies in the crust? (A) magnetic survey (B) gravity survey (C) observing drill core (D) analysing soil samples

9. Example 2: Searching for simple visual surface indications of mineralization is referred to as? (A) magnetic surveying (B) remote sensing (C) prospecting (D) seismic surveying

10. Your Turn . . . Take the time and complete the following questions . . .(Solutions to follow) Questions: Which exploration method releases shock waves into a layer of rock and records them when they return to the surface? (A) gravity surveying (B) magnetic surveying (C) remote sensing (D) seismic surveying

11. Solutions . . . Questions: Which exploration method releases shock waves into a layer of rock and records them when they return to the surface? Answer: (A) gravity surveying (B) magnetic surveying (C) remote sensing (D) seismic surveying

12. Summary . . . Overview of Points covered: Exploration Techniques Include: Remote sensing Geological mapping Geochemical surveys Bulk sampling Observing drill cores Prospecting Cross-sections Magnetic survey Gravity survey