Premovic, Pavle I.
October 29, 2020
Cretaceous-Paleogene, asteroid, impact, boundary, clays, iridium
The prominent Cretaceous-Paleogene boundary clays of marine origin are characterized by their 0.2 - 0.4 cm thick basal layer so-called the ejecta layer anomalously enriched with mostly extraterrestrial iridium. It is now generally agreed that this iridium originated from the globally dispersed submicron impact dust originated from the carbonaceous chondritic impactor of the Chicxulub impact (Mexico). This note shows that the previous estimation of the mass (1013 - 1014g) of this dust by Pope  is probably greatly underestimated. On the other hand, the far higher mass assessments (ca. 1017 g) by Alvarez et al. , Toon et al. , and Moore et al.  are far more satisfactory.