Lecture 10 - Economic Geology

Question 1

What are the 3 largest metallic commodities produced in Canadian mines

Answer 1

Gold, iron and copper

Question 2

What’s an alloy?

Answer 2

Compound which is synthesized by mixing metals together

Question 3

Most ore minerals of the scarce metals are found as ______

Answer 3

Sulphides

Question 4

A few ore minerals such as tin and tungsten are

Answer 4

Oxides

Question 5

True or false. Ore minerals rarely occur alone

Answer 5

True

Question 6

Ore minerals are mixed with other non-valuable minerals, collectively termed as

Answer 6

Gangue

Question 7

A bad thing of mining is acid mine drainage. Meaning what

Answer 7

Oxidation and hydrolysis of sulphide minerals which exist with ore minerals

Question 8

______ codified understanding of ore deposits. 350 years later _____ started understanding the processes and not just characterizing it

Answer 8

Agricola

Lindgren

Question 9

What are the 3 essential requirement for making ore deposits

Answer 9

Source
Transport
Trap

Question 10

Minerals become concentrated in which 5 ways

Answer 10

COPY PASTE

Question 11

What is the common aspect of the 5 ways in which ore minerals are precipitated

Answer 11

Fluids are part of the transport and concentration mechanism

Question 12

What type of rock is associated with metallic mineral deposits

Answer 12

Igneous, sedimentary and metallic

Question 13

What are the 3 types of metallic mineral deposits

Answer 13

Magnetic ore deposits
Deposits associated with metamorphism
Hydrothermal ore deposits

Question 14

What is fractional crystallization/magmatic differentiation ?

Answer 14

Heavy minerals that crystallize early, settle and concentrate on the bottom of the magma chamber

Question 15

What type of mineral sunk to the bottom of the magma chamber

Answer 15

High density minerals such as chromite

Question 16

What is imbiscibility

Answer 16

Segregation of metal-rich (sulphide) liquid from the crystallizing magma

Like oil and water

Question 17

What is pegmatites

Answer 17

Metal remaining in last stages of crystallization or granitic magma is rich in volatiles and rare elements

Question 18

Many important ore deposits are produced by METAMORPHISM of country rocks adjacent to an intrusion. There’s are referred to as

Answer 18

Skarns

Question 19

Hydrothermal ore deposits associated with igneous activity are called

Answer 19

Veins, disseminated or volcanogenic massive sulphides (VMS)

Question 20

What are the most common vein minerals ?

Answer 20

Quartz and calcite

Question 21

Where do hydrothermal fluids come from?

Answer 21

Sea water, rain water, magmas

Question 22

What’s the difference between disseminated deposits and veins?

Answer 22

In disseminated deposits metals are distributed throughout the rock body rather than concentrated in veins (low grade, large volume)

Question 23

Most of the worlds copper comes from where ?

Answer 23

Hydrothermal veins and dissemination’s derived from large prophyritkc intrusions

Question 24

What are VMS deposits

Answer 24

Lenses of sulphide minerals that accumulate on the sea floor from hydrothermal vents

Question 25

What are SEDEX? Sedimentary exhalitive deposits

Answer 25

Massive sulphide deposits that form from seafloor hydrothermal vents in sedimentary basins. They usually occur in sediment that fills rift basins

Question 26

What are placer deposits

Answer 26

Formed when heavy metals are mechanically concentrated by currents in rivers

Question 27

What’s an example of placer deposits

Answer 27

Gold, platinum, diamonds, tin

Question 28

What is laterite deposits

Answer 28

Concentrate certain elements (Fe, Al, Ni) by leaching our other elements through deep weathering of parent rocks

Question 29

Super gene enrichment occurs when?

Answer 29

When soluble minerals are dissolved near the surface and repricitatee at depth near the water tables

Question 30

Most diamonds are found where?

Answer 30

In rare ultra mafic igneous rocks called kimberlites

Question 31

Where is coal found?

Answer 31

From the decay and compression of land plants rich in resins, waxed and lignins

Question 32

How is oil and gas unlike coal

Answer 32

Oil and gas is derived from the remains of marine plants and animals rich in protein lipids and carbohydrates. Aka coals are terrestrial and oil/gas is marine

Question 33

What are the hazards/dangers of fracking

Answer 33

Earthquakes Contamination of domestic water wells Escape of methane from gas we’ll head Destruction of landscapes

Question 34

Where are gas hydrates found?

Answer 34

Cold temp relatively high pressure at the bottom of ocean basins I’m hydrated sediment layers.

Question 35

How is gas hydrates produced

Answer 35

Methane produced from the breakdown of biological material