Question

At a convergent subduction boundary:

a. Two plates collide head-on and deform upwards, forming mountains and other features.
b. Two plates slide past one another, grinding the rock at the boundary.
c. A denser continental plate moves below a less dense oceanic plate when they collide.
d. A denser ocean plate moves below a less dense continental plate when they collide.

Answer 1

where a denser oceanic plate subducts beneath a less dense continental plate, leading to features like deep oceanic trenches and contributing to mountain building and volcanic activities.

Step-by-step explanation:

At a convergent subduction boundary, the correct answer is: d. A denser ocean plate moves below a less dense continental plate when they collide.

In a subduction zone, oceanic crust, being denser and thinner, is more easily thrust down into the upper mantle beneath a continental plate. This process is marked by the presence of deep oceanic trenches and results in the recycling of the oceanic plate material through high pressure and temperature conditions, contributing to the convection currents within Earth's mantle. Subduction zones are significant geological features that lead to the formation of mountain ranges, volcanic activity, and earthquakes, as the descending plate melts and interacts with the mantle and overlying crust.

For instance, the Appalachian Mountains in North America were formed from such tectonic forces over millions of years. Moreover, subduction zones balance the creation of new crust at rift zones, where tectonic plates are diverging, demonstrating the dynamic nature of Earth's lithosphere.