A geological survey team is mapping seismic activity and topographical features across a specific coastal region. They observe a deep ocean trench running parallel to the continental coastline. Seismic data reveals that earthquakes originate at shallow depths near the trench and occur at progressively greater depths extending hundreds of kilometers inland beneath the continent. Based on these observations, which of the following best describes the tectonic process occurring in this region and its resulting geological features?
- A denser oceanic plate is subducting beneath a less dense continental plate at a convergent boundary, which typically produces an inland volcanic mountain range.Answer
- BTwo tectonic plates are pulling apart at a divergent boundary, allowing magma to rise and rapidly cool into sedimentary rock formations along the trench.
- CTectonic plates are sliding laterally past one another at a transform boundary, causing intense seismic friction that creates the deep trench.
- DTwo continental plates of equal density are colliding at a convergent boundary, causing the crust to buckle downwards to form a trench and upwards to form mountains.
Answer
A denser oceanic plate is subducting beneath a less dense continental plate at a convergent boundary, which typically produces an inland volcanic mountain range.
The scenario perfectly describes an oceanic-continental convergent boundary. The ocean trench marks the subduction zone where the denser oceanic plate dives beneath the continental plate. The progressively deeper earthquakes track the descending plate as it moves into the mantle. This process generates magma, leading to the formation of a volcanic mountain range inland.
Step-by-Step Solution
Key Concept
Convergent boundaries involving subduction create distinct topographical features (trenches, volcanic arcs) and specific seismic patterns (deepening earthquakes).
Estimated Time:1m 30s