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
Which stratigraphic principle states that in an undisturbed sequence of sedimentary rocks, the oldest layers are at the bottom?
Answer: Law of Superposition
The Law of Superposition, established by Nicolas Steno, is fundamental to interpreting the relative age and sequence of sedimentary rock units.
What is the primary use of a portable XRF (X-ray fluorescence) analyzer in mineral exploration fieldwork?
Answer: Rapid in-field geochemical analysis of element concentrations in rock and soil samples
Portable XRF provides fast multi-element geochemical data in the field, enabling real-time decision-making during drilling and sampling programs.
A 'gossan' in mineral exploration refers to:
Answer: An iron-oxide-rich cap formed by surface oxidation of an underlying sulfide deposit
Gossans are rust-colored iron hydroxide outcrops that form when sulfide ore bodies oxidize at the surface and are classic exploration indicators.
In the context of mineral resource estimation, what is the purpose of variography?
Answer: To characterize the spatial continuity and correlation of grade values for kriging interpolation
Variography quantifies how grade values become less correlated with increasing distance, defining the search ellipsoid parameters used in kriging estimation.
Which type of alteration zone, characterized by sericite, quartz, and pyrite, is typically found in the core of a porphyry copper system?
Answer: Phyllic (sericitic) alteration
Phyllic alteration is an intermediate zone in porphyry systems where feldspars are converted to sericite and quartz, often associated with pyrite halos.
What does the term 'geophysical inversion' mean in mineral exploration?
Answer: Mathematical modeling that converts surface geophysical measurements into subsurface physical property distributions
Geophysical inversion uses algorithms to compute 3D models of rock properties (density, susceptibility, resistivity) that best explain the observed surface data.
Kimberlite pipes are the primary source rock for which commercially important mineral?
Answer: Diamond
Kimberlites are volatile-rich ultramafic rocks that originate in the mantle and transport diamonds to the surface through explosive eruptions.