Final answer:
The statement that epicontinental seas are atop continental crust is true. These types of seas are formed when continental crust is submerged under shallow water, forming a shallow sea that covers part of the continental shelf.
Step-by-step explanation:
The statement that epicontinental seas are seas atop continental crust is true. Epicontinental seas, also known as epeiric seas, are shallow bodies of water that cover part of a continental shelf. When continental crust, which is composed of igneous, metamorphic, and sedimentary rocks, is submerged under shallow water due to various geological processes such as rising sea levels or subsidence, an epicontinental sea is formed.
Continental crust is less dense and thicker than oceanic crust, generally consisting of granite and other silicate minerals which allow it to rise higher on the mantle compared to the denser, mafic rock-based oceanic crust. Specific regions in the Earth's geological history, like the Kaskaskia Sea, are examples of epicontinental seas that formed due to continental collisions and the subsequent geological evolution, such as during the collision between North America and the Avalon terrane.
Similarly, the sediment deposits along the Coastal Plain from New England to Texas were a result of the accumulation of sediment since the rifting of Pangaea, forming shallow marine sedimentary environments that are often associated with epicontinental seas.