The glaciers deposited very distinctive beds of tillite (a rock formed from the mud/gravel/boulders left behind as a glacier melts).
(The glaciers; deposited; very distinctive beds of tillite) (a rock formed from the mud/gravel/boulders; left; behind; as a glacier melts) (a glacier; melts; )
The glaciers a rock formed from the mud/gravel/boulders a glacier
deposited left melts
very distinctive beds of tillite
behind as a glacier melts