footnote.sep.leader.properties
attribute set
footnote.sep.leader.properties
Properties associated with footnote separators
  black
  rule
  1in
Description
The styling for the rule line that separates the
footnotes from the body text.
These are properties applied to the fo:leader used as
the separator.
If you want to do more than just set properties on
the leader element, then you can customize the template
named footnote.separator in 
fo/pagesetup.xsl.