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The results from a laser probe can be plotted in several graphical ways, including a map of a grain showing lateral argon distribution.
Ar total fusion measures ratios, making it ideal for samples known to be very argon retentive (eg. Total fusion is performed using a laser and results are commonly plotted on probability distribution diagrams or ideograms.
Due to the relatively heavy atomic weight of potassium, insignificant fractionation of the different potassium isotopes occurs.
However, the Argon, a noble gas, constitutes approximately 0.1-5% of the Earth's present day atmosphere.
Mechanical crushing is also a technique capable of releasing argon from a single sample in multiple steps.
Argon loss and excess argon are two common problems that may cause erroneous ages to be determined.
Argon loss occurs when radiogenic K by a fast neutron reaction) can be used as a proxy for potassium.
Because the J value is extrapolated from a standard to an unknown, the accuracy and precision on that J value is critical.
J value uncertainty can be minimized by constraining the geometry of the standard relative to the unknown, both vertically and horizontally.