Question

how many geographical periods.​

Answer 1

Answer:

twelve

Structure. The twelve currently recognised periods of the present eon – the Phanerozoic – are defined by the International Commission on Stratigraphy (ICS) by reference to the stratigraphy at particular locations around the world. wlcm GY

Answer 2

$\huge\pink{Answer}$

• The twelve currently recognised periods of the present eon – the Phanerozoic – are defined by the International Commission on Stratigraphy (ICS) by reference to the stratigraphy at particular locations around the world.