What does the presence of new rock near an oceanic ridge indicate?
A. There is always a deep-sea trench underneath.
B. There is evidence of seafloor spreading.
C. They are made from oceanic crust.
D. They have iron oriented in different directions.
B. There is evidence of seafloor spreading.
The correct answer is B. There is evidence of seafloor spreading.
When new rock is found near an oceanic ridge, it indicates evidence of seafloor spreading. Oceanic ridges are formed by tectonic plates separating and magma rising from the mantle to fill the gap. As the magma solidifies, it forms new oceanic crust, which is the new rock being observed. This process is known as seafloor spreading, where new rock is continuously created at the oceanic ridges.
The correct answer is B. There is evidence of seafloor spreading.
When new rock is found near an oceanic ridge, it indicates the process of seafloor spreading. Oceanic ridges are formed by the divergence of tectonic plates at the bottom of the ocean where new crust is continuously being created. This process occurs when molten material, called magma, rises from the Earth's mantle and cools to form new rock, known as basalt, at the ridge. As the magma cools and solidifies, it forms new oceanic crust, pushing the existing crust away from the ridge.
As the new rock is formed, it creates a symmetrical pattern on both sides of the ridge, where older and cooler rock moves away from the center, making room for the newly formed rock. This process of seafloor spreading is one of the key mechanisms that drive plate tectonics on Earth.
In summary, the presence of new rock near an oceanic ridge indicates evidence of seafloor spreading, as it is a result of the continuous creation and movement of oceanic crust away from the ridge.