Here's your notary regulation regarding a journal:
A notary public is not required to keep a journal, ledger, list, etc., but many notaries find these to be effective methods for keeping records. If you keep a record of your notarizations, it is recommended that you record the signer's name, identification presented, date, type of document and other information you deem pertinent to the transaction.
If records are kept, the Michigan Notary Public Act requires a notary to maintain all records of a notarial act for at least 5 years. A notary is also required to provide copies of those records upon the request of the Department of State. However, the law does not describe the type of record that must be kept or what must be included in a record."
So, it looks like Michigan leaves it up to you whether or not you keep a journal and by this statement "and other information you deem pertinent to the transaction." whether or not you, as a matter of personal practice, require a thumbprint from your signers.