Midterm Exam – Multiple Choice

What distinguishes foliated metamorphic rocks from non-foliated?

• Presence of fossils

• Aligned mineral bands from pressure

• Cooling rate differences

• Color variation

Why do coastal wells eventually produce brackish water?

• Pollution from factories

• Saltwater intrusion from over-pumping

• Too much rainwater infiltration

• Strong waves

What feature of Eastern Philippines makes it storm-prone?

• Flat terrain

• High vulnerability → needs defenses & early warning

• Dry climate

• Few rivers

What does relative dating tell us about rocks?

• Exact numeric age

• Composition of minerals

• Age compared to surrounding layers

• Type of fossils

What does a hazard map’s red zones along a fault line mean?

• No risk

• High earthquake risk

• Safe for housing

• Flood-prone

Which process explains magma formation at subduction zones?

• Evaporation

• Hydration melting (water added to crust)

• Freezing

• Erosion

What’s the difference between phaneritic and aphanitic textures?

• Phaneritic = fast cooling, small crystals

• Phaneritic = slow cooling, large crystals; Aphanitic = fast cooling, small crystals

• Aphanitic = slow cooling, large crystals

• Both have same crystal size

What does deposition signify in erosion cycle?

• Breaking of rocks

• Transport of sediments

• Final step: sediments stored in new landforms (e.g., deltas)

• Weathering of minerals

What stress causes strike-slip faults?

• Compression

• Tension

• Shearing (rocks slide past each other)

• Folding

What allows Earth to sustain liquid water?

• Lack of atmosphere

• Stable temperature range & atmospheric pressure

• High volcanic activity

• Freezing poles