Answer:
Quartz is not pure in this rock.
Explanation:
When quartz shows effervescence in contact with an acid, it means that it is not in its pure state, but rather related to other substances that may be cementing the quartz. This effectiveness is caused by substances that do not react like quartz, such as calcite.
In this case, we can conclude that in relation to the calcium-rich rock shown in the question above, the calcium is not pure, but it is likely to be related to calcite, or other material that does not react to acid.
the oldest ocean floor is only 180 million years old, because the oldest crust is destroyed at subduction zones.
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What are subduction zones?</h3>
According to NOAA, tectonic plates are fragments of the Earth's hard outer layer that steadily travel across the surface of the globe over millions of years (opens in new tab). (This is a fundamental principle of the theory of plate tectonics, which holds that pieces of the Earth's crust slide across the lower mantle and carry continents with them.) According to the U.S. Geological Survey(opens in new tab), the Earth's crust and the top part of the mantle, a thick, heated layer under the crust, make up that outer layer, also known as the lithosphere (USGS). This lithosphere material curls downward into the heated mantle during subduction zones, when two tectonic plates collide and one slides beneath the other.
To know more about subduction zones, visit;
brainly.com/question/13788626?referrer=searchResults
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