12. Which of the following is least likely to be associated with eruption of a shield volcano?

a. a pyroclastic flow (nuée ardente)

b. pahoehoe lava

c. a'a' lava

d. small deposits of ash fall

a. a pyroclastic flow (nuée ardente)

Explanation:

A shield volcano is composed of entirely of thin lava flows that built up over a central vent. Shield volcanoes have very little pyroclastic material in them there is some amount of pyroclastic material present in the eruptive vents. All the other things that are : - pahoehoe lava, a'a' lava, small deposits of ash fall can be seen most likely in the eruption of shield volcano and least likely seen is the pyroclastic flow.