Indeed a manual correction posting is imaginable to peculiar depreciation.
Please usage the transactions ABZU(N/L), ABAA(N/L) etc, and prime the transaction types dedicated to close peculiar depreciatin.
Some examples are:
700 Write-up mean and peculiar depreciation
720 Write-up peculiar taxation depreciation
620 Manual spec. dep. connected prior-yr acquis per dep. key
630 Manual spec. dep. connected curr-yr acquis per dep. key
However, determination are nary transaction types connected unplanned peculiar depreciation. Please interaction your section SAP Consultant successful bid to make an ain transaction benignant for this purpose.