What is the white curved feature that extends from the base of the cone to its summit?

The white curved feature that extends from the base of a cone to its summit is typically referred to as the "mantle" or "slip layer." In geological terms, this can also be associated with the lava flow or volcanic rock that forms as material accumulates and solidifies around the vent of the volcano. This feature can indicate the path of volcanic activity and the movement of magma during eruptions.