1 Insertion â when a base is added to the sequence. 2  Deletion â when a base is deleted from the sequence.  Copy number variation (CNV) is a type of mutation where large chunks of DNA are inserted, repeated or lost. These regions of DNA can be between 10,000 and 5,000,000 bases long.
Wind deposition can result in dunes and loess deposits.
Stacks, stumps and caves. 1  These features are formed on cliffs or headlands. 2  Over time, the cave will be eroded into an arch, accessible to the sea on both sides. 3  Finally, the erosion and weathering continues and the arch collapses leaving behind a stack (a vertical column of rock) .