Main Bearing marks

Evening all
Attached are some unusual bearing marks-anyone seen similar?
The following is the set up:

1. Aspirated BBC endurance engine
2. .0035 main bearing clearance
3. Iron block
4. Coated bearings
5. Billet Crank
6. Merlin Doweled tall deck block
7. 90lb oil pressure
8. Max RPM 6200 RPM
9. Non bypass oil filter
10. Clearview screen-nothing captured
11. Crank checked for straightness and journal parallels, radius- all good

Your treasured thoughts all.