It is not from inside the oil pan area,it comes from the actual dipstick tube.
The tubes that you slide the dipstick into are not hardened steel(very cheap steel really).The dipstick it self is Hardened steel,it has very sharp edges on it that scrape the walls of the softer steel tube,this actually produces small (ultrasmall) slivers that stick to the dipsticks end.....are very common on ls engines.
A little test for the people that dont believe me -
DRAIN ALL YOUR OIL.
WIPE THE DIPSTICK CLEAN.
RE INSTALL THE DIPSTICK IN THE TUBE
REMOVE IT AND OBSERVE.
(THE CAMARO DIPSTICK IS VERY CURVED IN NATURE,HENCE THE HEAVY SCRAPPING OF THE WALLS OF THE TUBE)
Andy