Millions of years ago, tertiary volcanoes deposited their ash to form massive plateaus from the mountains of the region.
(tertiary volcanoes; deposited; their ash; to form massive plateaus from the mountains of the region; T:Millions of years ago) Context(tertiary volcanoes deposited,List([23, 51))):(tertiary volcanoes; deposited their ash to form; massive plateaus from the mountains of the region)
tertiary volcanoes deposited,List([23, 51))
tertiary volcanoes tertiary volcanoes
deposited deposited their ash to form
their ash to form massive plateaus from the mountains of the region T:Millions of years ago
massive plateaus from the mountains of the region