Metal plate

[infotraker]

My wife found this plate several years ago in a area near Folsom Lake , private property. The area is near old 1850's gold camps. It has hand made swirl decorations on the edges. Seems coppery or brass material. It was found under several inches of dirt with whites mxt, the area had been cleared many years prior for a house.
Has anyone ever seen a plate similar to this one ?