Geology & Mineral Exploration Flashcards
7 cards from real CMA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Geology & Mineral Exploration flashcards as text
What is the geological significance of a 'graben' structure in mineral exploration?
Answer: A down-dropped block bounded by normal faults, often hosting sediment-hosted mineral deposits
Grabens are rift-related structures where sediment accumulates and can host stratabound mineral deposits including lead-zinc and copper.
Which mineral is the primary ore of aluminum and forms by intense tropical weathering of aluminous rocks?
Answer: Bauxite
Bauxite is a lateritic ore composed mainly of aluminum hydroxide minerals formed by deep chemical weathering in tropical climates.
In the classification of coal, which rank has the highest carbon content and heating value?
Answer: Anthracite
Anthracite has the highest carbon content (>86%) and heating value among coal ranks, formed by maximum coalification under heat and pressure.
A volcanogenic massive sulfide (VMS) deposit is best described as:
Answer: A seafloor hydrothermal deposit of sulfide minerals formed at or near volcanic centers
VMS deposits form when seafloor hydrothermal vents precipitate massive sulfide lenses of copper, zinc, and lead near submarine volcanic centers.
Which exploration tool uses variations in Earth's magnetic field to locate iron-bearing mineral deposits from aircraft?
Answer: Airborne magnetic survey
Airborne magnetic surveys measure total magnetic field intensity, effectively identifying magnetite-bearing rocks and iron ore deposits over large areas rapidly.
What does a 'soil geochemical anomaly' represent in mineral exploration?
Answer: An area where metal concentrations in soil exceed background levels, potentially indicating a buried deposit
Soil geochemical anomalies identify areas where metals have migrated upward from buried mineralization and provide exploration drill targets.
The Carlin-type gold deposit, named after deposits in Nevada, is characterized by:
Answer: Microscopic gold disseminated in sedimentary carbonate rocks altered by hydrothermal fluids
Carlin-type deposits contain submicron gold trapped in arsenian pyrite within decarbonated and silicified limestone, making them unique and very large.