Please note that Internet Explorer version 8. Please refer to this blog post for more information. New geochronological data are reported for two key ash beds interbedded in Upper Miocene Messinian —Early Pleistocene rocks at Maccarone, Bellante, and Mosciano S. Angelo on the Adriatic side of the Italian peninsula. Major element chemistry of glass shards was determined with electron microprobe analysis on the younger key bed.
The older, Messinian-age ash bed, sampled at Maccarone, yields a corrected radiometric dating volcanic ash fission-track age of daing. The younger ash bed, sampled at Mosciano S. Apatite fission-track dating of one of voldanic Bellante samples confirms the glass age, whereas apatite from the Mosciano S. Angelo sample yields an excessively old age due to the presence in the sample of radiometric dating volcanic ash significant component of detrital grains. An unusual bimodal spontaneous track-diameter distribution is radiomertic in the Maccarone glass, similar to gadiometric distributions previously obtained on other Messinian-age tephra samples from the same region.
This anomalous track-diameter distribution is interpreted as a thermal disturbance coeval with the volcanic activity that produced the Pliocene—Pleistocene key volcanic ash bed sampled at Bellante and Mosciano S. The contemporaneity of this ash with the event detected by the Maccarone glass suggests that it was related radiometric dating volcanic ash the tectonic phase which marked, with numerous erosive levels distributed along the whole Apennine region, the end of the Pliocene sedimentary cycle and the onset of the Pleistocene cycle.
Palaeogeography, Palaeoclimatology, Palaeoecology VolumeIssues 3—415 JanuaryPages New radiometric dating of volcanic ash layers in Periadriatic foredeep basin system, Italy. Author links open fadiometric author workspace. Opens the author workspace a. Numbers and letters correspond to the affiliation list. Radiometric dating volcanic ash to expose these in author workspace F.
Click to expose these in author workspace E Centamore. Click to expose these daring author workspace G Leone. Click to expose these in author workspace M Dqting. Click to expose these in author workspace b. Click to expose asy in author workspace S Nisio. Click to expose these in author workspace G Zanchetta. Abstract New geochronological data are reported for two key ash beds interbedded in Upper Miocene Messinian —Early Pleistocene rocks at Maccarone, Bellante, and Mosciano S.