WARNING: This page is about a different car, the 2003 GMC Safari and 2003 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Brinelling
Courtesy of GENERAL MOTORS CORP.
Surface indentations in the race way caused by the rollers under impact loading or caused from vibration while the bearing is not rotating. Replace a rough or noisy bearing.