isochron

English

A diagram showing how isochrons can be used to determine the initial concentration of a radioisotope

Etymology

iso- +‎ chron.

Noun

isochron (plural isochrons)

1. (geology, geochemistry) A line on a chart linking rock of the same age (as determined from isotope ratios).
   • 1997, H.-G. Attendorn, R. Bowen, Radioactive and Stable Isotope Geology, Chapman & Hall, page 163:

     Recapitulating, any suite of comagmatic rocks with an age $t$ defines an isochron if its members all had the same initial ${\ce {^{87}Sr/^{86}Sr}}$ ratio and if it was closed to both ${\ce {Rb}}$ and ${\ce {Sr}}$ since crystallization occurred and neither element was introduced from any extraneous source. […] In this way, whole-rock ${\ce {Rb-Sr}}$ isochrons can produce rather reliable age data for rock samples.

2. (mathematics, dynamical systems) A collection of points (such as a manifold), each point representing a set of initial conditions for a given dynamical system, such that every set results in the same long-term behaviour of the system.
   • 2007, Eugene M. Izhikevich, Dynamical Systems in Neuroscience, The MIT Press, page 446:

     The entire plane is foliated by isochrons.

Derived terms

• isochron dating
• isochron diagram

Related terms

• isochronism
• isochronous
• isochrony

Translations

line on a chart linking rock of the same age

• French: please add this translation if you can
• German: Isochrone (de) f
• Italian: please add this translation if you can

collection of points representing initial conditions of a dynamical system

• French: please add this translation if you can
• German: Isochrone (de) f
• Italian: please add this translation if you can

See also

• isochrone

Further reading

• Isochron on Wikipedia.Wikipedia (mathematics)
• Isochron dating on Wikipedia.Wikipedia

Anagrams

• chorions