How did new evidence found by Marie Tharp and Bruce Heezen add onto continental drift and create the theory of plate tectonics?

Question

1. they proposed that continental are pieces of the Earth's crust floating on top of the mantle.
2. they proposed that mountain ranges at the edge of continents helped explain how continents used to fit together.
3. they showed fossils of the same organism on multiple continents helped explain how continents float on the mantle.
4. they showed what the ocean's floors looked like helped explain how continents move over time.

Answer 1

All of the options listed are correct, as they all played a role in adding onto the theory of continental drift and eventually leading to the development of the theory of plate tectonics.

1. Marie Tharp and Bruce Heezen proposed that continents are actually pieces of the Earth's crust that float on the semi-fluid mantle layer underneath. This idea supported the concept of continental drift and the movement of continents.

2. Through their research, Tharp and Heezen observed mountain ranges at the edges of continents and noticed that they aligned with mountain ranges on other continents. This observation suggested that continents may have been connected in the past and provided further evidence for continental drift.

3. By studying fossils of the same organisms found on different continents, Tharp and Heezen suggested that these organisms could not have crossed vast oceans but instead were part of the same landmass that later drifted apart. This finding supported the idea of continental drift and the movement of continents.

4. One of the significant contributions of Tharp and Heezen was the mapping of the ocean floor, which showed the presence of features such as mid-ocean ridges and deep-sea trenches. These maps revealed the topography and composition of the ocean floors and provided evidence for sea floor spreading, a process that helps explain how continents move over time.

By combining these findings, Tharp and Heezen not only added to the evidence for continental drift but also paved the way for the development of the theory of plate tectonics, which explains the movement of Earth's lithospheric plates, including the continents.