ASBOG - Association of State Boards of Geology Economic Geology and Energy Questions and Answers 2

Question 1

Which type of ore deposit forms when hydrothermal fluids precipitate minerals along faults and fractures in host rock?

Accepted Answer

Vein deposit

Answer

Placer deposit

Answer

Evaporite deposit

Answer

Residual deposit

Question 2

What is the primary driving force behind the formation of sedimentary exhalative (SEDEX) deposits?

Accepted Answer

Magmatic intrusion heating basin brines

Answer

Glacial transport and deposition

Answer

Wind erosion concentrating heavy minerals

Answer

Biological activity fixing metals in sediments

Question 3

Which energy resource is primarily associated with organic-rich black shales deposited in anoxic marine basins?

Accepted Answer

Shale gas and oil

Answer

Coal

Answer

Uranium

Answer

Geothermal energy

Question 4

A geologist identifies a porphyry copper deposit. What is the most common tectonic setting for this deposit type?

Accepted Answer

Convergent plate margin above a subduction zone

Answer

Mid-ocean ridge

Answer

Continental rift zone

Answer

Transform fault boundary

Question 5

In petroleum geology, what is the term for impermeable rock that prevents upward migration of hydrocarbons, trapping them in a reservoir?

Accepted Answer

Seal rock (cap rock)

Answer

Source rock

Answer

Reservoir rock

Answer

Basement rock

Question 6

Which geochemical process is responsible for the supergene enrichment of copper ore deposits?

Accepted Answer

Downward percolation of oxidizing groundwater dissolving and re-precipitating copper

Answer

Metamorphic recrystallization of primary sulfides

Answer

Magmatic differentiation concentrating copper in late-stage melts

Answer

Evaporation of saline lake waters depositing copper salts