Question

Long Valley is a volcanic caldera that erupted lava. Its main eruption about 760,000 years ago was a(n) ____ eruption. It is located at a(n) ____ zone, and it is of the subtype ____. It is found on the ____ plate.

A) Explosive, Subduction, Stratovolcano, Oceanic

B) Effusive, Rift, Shield, Continental

C) Effusive, Subduction, Cinder Cone, Oceanic

D) Explosive, Rift, Caldera, Continental

Answer 1

The main eruption of the Long Valley Caldera about 760,000 years ago was an explosive eruption, occurring at a rift zone and forming a caldera on the continental plate.

Step-by-step explanation:

D) Explosive, Rift, Caldera, Continental.

Long Valley Caldera is an example of a volcanic feature that formed due to explosive volcanic activity. These types of eruptions are characterized by the rapid release of gases and pyroclastic materials, which can result in significant alterations to the landscape and the formation of large calderas. The Long Valley eruption that occurred approximately 760,000 years ago was indeed explosive and resulted in the formation of a significant caldera. This volcanic activity did not occur at a subduction zone, but rather at a rift zone, which is a type of tectonic boundary where the Earth’s crust is being pulled apart. Rift zones typically lead to the formation of features like the Long Valley Caldera. Additionally, the Long Valley Caldera is categorized as a caldera, which is a subtype of volcano that forms when a magma chamber empties and collapses, as opposed to a stratovolcano or shield volcano. Lastly, Long Valley Caldera is located in eastern California and therefore is part of the continental crust.