The amount of Ar is also measured to assess how much of the total argon is atmospheric in origin. 11) the following assumptions must be true for computed dates to be accepted as representing the true age of the rock: Both flame photometry and mass spectrometry are destructive tests, so particular care is needed to ensure that the aliquots used are truly representative of the sample.Ar–Ar dating is a similar technique which compares isotopic ratios from the same portion of the sample to avoid this problem.Ar atoms are able to diffuse through and escape from molten magma because most crystals have melted and the atoms are no longer trapped.
The Levant Volcanic extends through northeastern Jordan and Syria to the Golan Heights.
Minor volcanic fields also developed in the northern Israel, around the Hula Valley (northern Israel) and in southern Lebanon.
The present Dead Sea Rift in northern Israel began to subside at the end or after this phase, and the Upper Pliocene basalts flowed into it from Lebanon to the Hula Valley.
Pleistocene volocanic sources were recognized only in the eastern side of the Rift.
This province is a part of an extensive volcanic field which developed during the Cenozoic in the northwestern part of the Arabian plate, aligned roughly in a northwestern direction, subparallel to the Red Sea.