It's certainly not possible to clone a block in full, because part of each block is the link to the previous block via its hash, and there's no chance that will be identical for two different blocks in the same chain. Similarly, transactions reference each other in their inputs, so you can't clone transactions in full.
The best you can do is look at what is done in the transactions in one block, and create a new set of transactions to do the same thing.
But can I ask why you would want to do this?
