Pb‐Zn deposits by tectonic expulsion?

The tectonic expulsion of fluids theory could explain the presence of lead-zinc ores in sedimentary rocks. Originally proposed in 1986 by Jack Oliver, Cornell University, Ithaca, N.Y., the theory is based on the subduction of tectonic plates, where hot mineral-bearing fluids would be expelled from the subduction zone to circulate in overlying sediments during a continent-continent collision. The problem with Oliver's idea is that formation ages of some lead-zinc deposits are older than the formation ages of mountains close to the deposits. According to the theory, the age of the mountains would equal the age of mineralization.