noun isochron A line on a diagram or map connecting points relating to the same time or equal times. 1
noun isochron (geology) A line on a chart linking rock of the same age (especially as measured using the ratios of lead isotopes). 0
noun isochron a line on an isotope ratio diagram denoting a suite of rock or mineral samples all formed at the same time. The slope of the line is related to the age of the rock or mineral suite 0
noun isochron a line or curve on a geological map or cross section (esp of oceanic crust) connecting points of identical age 0
