Predicting the presence of tephra layers in lacustrine deposits using spectral gamma ray data: An example from Lake Chalco, Mexico City
Fig 5
Tephra index distribution for known and non-tephra samples.
Boxplot showing the distribution of the tephra index (TI) for the known tephra and non-tephra samples. The cut-off was made at the lower quartile of the tephra distribution (TI = 0.47). The accuracy of this model for the known sample sets is 85%.