Question

A geologist is looking at deposits along a river below a large volcano. She finds large boulders mixed with sand and mud, and all of the material is comprised of volcanic rocks, particularly the mud which is volcanic ash. She quickly realizes these deposits represent an ancient ________. a. lahar b. earthflow c. rock avalanche d. slump

Answer 1

lahar

Step-by-step explanation:

• A lahar is a violent type of mudflow that is composed of slurry materials and is mixed with the rocky debris and water. Hence these are material that are coming down from a volcano in the form of a lahar along the river valley.

• Have a speed of 22 or more mph, and known to be 140 meters long.

• Being a volcanic mudflow or debris has consistency and viscosity along with an approximate density of fluids caused by the snow and glacier melts.

• Earthquakes and rainfall can also trigger this event.