I'm trying to distinguish what it is you are seeing and experiencing. Is it perhaps a secondary clay deposit over an existing primary deposit? The lead/metal oxides could have traveled with the sedimentary second layer coming to rest here.
There is one more thing of interest, there is a small spring of water flowing out of the clay vein. Burntbear , you could be right.
About 200 feet above the cut is where the fan tapers/starts, i have found gold flecks there.
Gold washer, you can not see the fan because i have not got a picture posted on here. The fan starts up the hill , it is 20 feet wide and fans out about 200 feet below the start, were its about 200 feet wide and it is fan shaped.