Answer:
The answer could be either pampas, gran chaco, or patagonia
Explanation:
The reason why it could be those is because they are all located in the Argentina area which is very close to Uruguay(where rio de la plata is) but in my opinion I would choose pampas because they are the only ones out of the three that are located in Uruguay as the Rio de la Plata
What did Harry Hess discover that helped prove that tectonic plates are moving?
Answer:
He realized that the Earth's crust had been moving away on each side of oceanic ridges, down the Atlantic and Pacific oceans, that were long and volcanically active. He published his theory and it came to be called “seafloor spreading.”