Lec 2 - Mine Exploration

Question 1

What are the steps in exploration?

Answer 1

• select potential area
• collect regional data and define local target area
• reconnaissance explo
• geophysical and geochemical exploration
• reconnaissance and bracket drilling
• ore discover

Question 2

Potential areas

Answer 2

• areas of known production
• areas of known occurence
• favorable conditions for deposition

Question 3

Collect regional data and define local target area:

Answer 3

• historical data, state surveys, archives
• univ research programs
• compamy reports

Question 4

Types of Remote Sensing

Answer 4

• DEM - Digital Elevation Model
• TM - Landsat Thematic Mapper
• ASTER - Advanced Spaceborne Thermal Emission and Reflection
• Hyperspectral Remote Sensing
• NOAA-AVHR - National Oceanic And Atmospheric Administration- Advanced Very High Resolution Radiometer

Question 5

The science of remotely acquiring, processing and interpreting spectral information about the earth’s surface and recording interaction between matter and electromagnetic energy

Answer 5

Remote Sensing

Question 6

• A way to gather and present geologic data
• shows how rock and soil on the earths surface is distributed
• predict what is below the earth’s surface

Answer 6

Geologic Mapping

Question 7

Things you need in Geological Mapping

Answer 7

• field notebooks
• rock hammer
• hand lens
• pocket knife
• magnet
• clipboard
• pencils
• scale protacters
• tape measure
• camera
• gps
• brunton compass
• radiograph type pens

Question 8

What are the things you need to identify during geol mapping

Answer 8

• rock units and relationship
• host rock characteristics
• structures
• alteration
• gangue minerals
• ore mineralogy
• rock sampling

Question 9

It helps narrows a region to a smaller area of specific interest

Answer 9

Reconnaissance

Question 10

Scale of a detailed map

Answer 10

1:10,000 or 1:12,000

Question 11

Geochemical Sampling

Answer 11

• ground water
• surface water
• stream sediments
• soils
• biological
• ore samples

Question 12

2 types of sampling program

Answer 12

1. Reconnaissance

2. Field Inspection

Question 13

Surface grab sampling over all exposures of gravel, few seismic cross section, geobotanical study, and survey for old workings

Answer 13

Field Inspection

Question 14

Lab Analysis

Answer 14

• host rock characteristics
• ore mineralogy
• alteration mineralogy
• age dating
• fluid inclusion
• isotope geochemistry

Question 15

Process whereby rigs or hand operated tools are used to make holes to intercept an ore body, and is the ultimate stage in exploration

Answer 15

Drilling

Question 16

Purposes of drilling

Answer 16

• to define the ore body at depth
• to access ground stability
• to estimate the tonnage and grade of a discovered minera deposit
• to determine presence or absence of ore bodies, veins or other type of mineral deposit

Question 17

Common types of drilling

Answer 17

• Auger Drilling
• Diamond core drilling
• reverse-circulation drilling
• hydraulc rotary drilling

Question 18

Uses a helical screw called “fighting” which acts as a conveyor to remove drilled out material

Answer 18

Auger Drilling
-low cost
-fast rate penetration
-free of contaminating fluid
But...
-effective only for unconsolidated material
-slower than other methods
-heavy equipments

Question 19

Utilizes a diamond drilling bit to obtain a cylindrical core of rock (core sample)

Answer 19

Diamond Core Drilling
-quick and can be done anywhere
-very little dust
-provide more geological info
-precise and has minimal damage to envi
But....
-noise
-limited size of drill bits

Question 20

A method of drilling which uses dual wall drill rods that consists of an outer drill rod with an inner tube. These hallow inner tubes allow the drill cuttings to be transported back to the surface in a continuous steady flow

Answer 20

Reverse-Circulation Drilling
- drilling cost can be reduced by fast rate of penetration
-requires less water
-quick sample retrieval
But….
-the samples retrived has less geological relevance

Question 21

Employs a sharp rotational drill bit to bore into the crust; typically uses tricone bits

Answer 21

Hydraulical Rotary Drilling
-can drill greater depths than diamond drilling
But…..
-more expensive
-has bigger footprint than diamond drilling

Question 22

High pressure safety valve system at the top of the well head which stops uncontrolled fluid/gas flow in the well bore

Answer 22

Blowout Preventor (BOP)