Question

it formed as continental crust detached from the continent at a transform plate boundary. it formed in an island arc as the volcanic islands fused together. it formed from flood basalts associated with a hot spot. it is oceanic crust uplifted by a large thrust fault. content new job explain how sea floor features form. 5 of 5 back to south america, where we can see both oceans near the southern tip of the continent, with the atlantic ocean to the east and the pacific ocean to the west. which of the following statements is true? there is an ocean trench along the atlantic coastline. there is an island arc just off the west coast of south america. there is a passive continental margin on the eastern side of south america. there are oceanic plateaus just offshore in both oceans.

Explanation:

To determine the correct statement, we analyze each option:

1. Ocean trench along Atlantic coastline: Ocean trenches are typically found at convergent boundaries (e.g., along the Pacific coast of South America due to subduction). The Atlantic coast of South America has a passive margin, not a trench - eliminate this option.
2. Island arc just off the west coast: An island arc forms at a convergent boundary where an oceanic plate subducts under another oceanic plate (e.g., Japan, Philippines). The west coast of South America has a continental - oceanic subduction zone (Andes Mountains are a continental volcanic arc, not an island arc) - eliminate this option.
3. Passive continental margin on the eastern side: A passive continental margin occurs where a continent - ocean boundary has no active tectonic activity (no subduction, rifting, etc.). The eastern coast of South America (Atlantic side) is a passive margin, as it is part of the South American - African plate boundary that is now a divergent margin in the ocean (Mid - Atlantic Ridge), and the continental edge has no active subduction or rifting - this is correct.
4. Oceanic plateaus just offshore in both oceans: Oceanic plateaus are large, flat - topped seamounts. The Pacific coast has a subduction zone with a deep ocean trench, not an oceanic plateau. The Atlantic coast has a continental shelf, slope, and rise (passive margin features), not an oceanic plateau - eliminate this option.

Answer:

There is a passive continental margin on the eastern side of South America.