What is "marked variation"?

Question

I was reading a science paper and the phrase was "A marked variation in ages was found in the isochron method using different parent-daughter analyses. " I'm finding myself having to look up each term and well, what is 'marked variation'?

Answer 1

A marked variation is a difference.  It's probably close to being statistically different, but not quite, so they've termed it "marked variation"

Answer 2

It's hard to say without seeing the paper in context, but it sounds like they're saying the age returned by dating varies when you use different initial parent-daughter radioactive isotope amounts.

As it should.