CXC - Caribbean Examinations Council Geography: Plate Tectonics Questions and Answers — Questions and Answers
Question 1: The chain of volcanic islands forming the Lesser Antilles, including St. Vincent, Martinique, and Montserrat, is a direct result of which tectonic process?
- The separation of the Caribbean and South American plates, allowing magma to rise.
- The North American Plate sliding horizontally past the Caribbean Plate.
- The subduction of the Atlantic seafloor beneath the Caribbean Plate. (Correct answer)
- Two continental plates colliding and buckling upwards to form mountains.
Correct answer: The subduction of the Atlantic seafloor beneath the Caribbean Plate.
The Lesser Antilles is a classic volcanic island arc formed at a convergent plate boundary. Here, the denser oceanic crust of the North American and South American plates subducts, or slides beneath, the less dense Caribbean Plate. As the subducting plate melts at depth, magma is generated and rises to the surface, forming the chain of volcanoes.
Question 2: The Enriquillo-Plantain Garden Fault Zone, which was responsible for major earthquakes in Haiti and Jamaica, is an example of which type of plate boundary?
- Convergent boundary
- Subduction zone
- Divergent boundary
- Transform boundary (Correct answer)
Correct answer: Transform boundary
A transform boundary occurs where two tectonic plates slide horizontally past one another. The Enriquillo-Plantain Garden Fault Zone is a major left-lateral strike-slip (transform) fault system that accommodates much of the relative motion between the Caribbean Plate and the North American Plate.
Question 3: Which of the following is considered the primary driving mechanism for the movement of Earth's tectonic plates?
- Convection currents in the mantle. (Correct answer)
- The gravitational pull of the Sun and Moon.
- The rotation of the Earth on its axis.
- Erosion and sediment deposition on continental shelves.
Correct answer: Convection currents in the mantle.
Convection currents in the semi-molten mantle are the primary driving force behind plate tectonics. Hot, less dense material from deep within the mantle rises, cools, and then sinks, creating slow, circular movements. These currents exert a drag on the overlying lithospheric plates, causing them to move.
Question 4: A student studying a geological map of Trinidad observes that the Northern Range is primarily composed of metamorphic rocks like schists and quartzites that have been intensely folded. This landform is the result of which tectonic process?
- The formation of a shield volcano from gentle lava flows.
- Rifting and the creation of a new ocean basin.
- Compression and folding at a convergent plate boundary. (Correct answer)
- Lateral movement along a strike-slip fault.
Correct answer: Compression and folding at a convergent plate boundary.
The Northern Range in Trinidad is a series of fold mountains. Its formation is a result of intense compressional forces at the complex convergent boundary between the Caribbean and South American plates. This compression caused sedimentary and metamorphic rock layers to buckle and fold, uplifting them to create the mountain range.
Question 5: Which of the following BEST defines the process of subduction?
- Two plates moving apart, allowing magma to create new crust.
- One tectonic plate sliding under another and sinking into the mantle. (Correct answer)
- Two continental plates colliding to form a high mountain range.
- Two plates sliding horizontally past each other, causing earthquakes.
Correct answer: One tectonic plate sliding under another and sinking into the mantle.
Subduction is the geological process that occurs at convergent boundaries where one tectonic plate, typically denser oceanic crust, moves under another plate and is forced to sink into the mantle. This process is responsible for creating deep-sea trenches and volcanic arcs.
Question 6: Which set of natural hazards is MOST characteristic of the convergent plate boundary found along the Eastern Caribbean?
- Formation of rift valleys and geysers.
- Widespread desertification and dust storms.
- Powerful earthquakes and explosive volcanic eruptions. (Correct answer)
- Formation of sand dunes and gentle lava flows.
Correct answer: Powerful earthquakes and explosive volcanic eruptions.
The convergent boundary in the Eastern Caribbean is a subduction zone, which is known for producing powerful earthquakes as the plates grind against each other. It also leads to the formation of stratovolcanoes (like La Soufrière and Mount Pelée) which often have violent, explosive eruptions due to the composition of the magma generated by the subduction process.
CXC - Caribbean Examinations Council Geography: Plate Tectonics Questions and Answers
The chain of volcanic islands forming the Lesser Antilles, including St.
Vincent, Martinique, and Montserrat, is a direct result of which tectonic process?