Like other keyboard instruments, the marimba can be bowed. Despite its superior size, it is limited in its sound production. Bowed marimba is particularly quiet and is unable to cut through most textures, so it’s important to be mindful of employing this technique in a dense piece. Additionally, the more piercing high notes of the marimba speak considerably softer than their lower counterparts.
A bowed marimba note will only resonate for as long as it is bowed before quickly dying. The lowest bars will resonate for a moment, but not in a way comparable to a vibraphone; there isn’t a real sustain ability on the marimba. Keep in mind that the lowest bars of a marimba are very long, so reaching over the instrument to bow an accidental could prove difficult.
In terms of notation, this should be treated in a similar manner to vibraphone.