How are past volcanic eruptions most commonly recorded in the geologic record?
A) by changes in rock cracks
B) by fossils of organisms that died during the eruptions
C) by deposits of ash and lava
D) by changes in the water table

Question

Quizplus · Accepted Answer

Past volcanic eruptions are most commonly recorded in the geologic record by deposits of ash and lava. During an eruption, the volcano can spew molten lava and ash into the atmosphere which then falls to the ground and forms layers of ash and lava deposits over time. These layers can be seen in sedimentary rocks and provide a record of past volcanic activity.

How Are Past Volcanic Eruptions Most Commonly Recorded in the Geologic