Morrison Formation/dark rocks in middle , are the Manganese stained rocks/not a lot, but shows effect of hydro-thermal vents. there are sulfide ores (usually contain cu,Pb,Zn,Au,Ag,etc) and complex salt ores in the Morrison Formation
Morrison Formation/Dark brown on rocks is Iron leaching out of Morrison Formation/aging gives Iron, a sheen look/the Iron is cause by a combination of salts and sulfides
2dark black/high in Manganese/put in by Hrydo-thermal Vents /Think of the Crabs,calms,etc. living at 20,000 feet living on that type of solution.(that happens on Earth) /also note thickness of Maganese only 1/16 or less thick.
