چكيده لاتين :
The study of planktonic foraminifera in Jorband section reveals two major
events in Campanian- Maastrichtian boundary and early-late Maastrichtian biodiversification.
In this study, occurrence and species richness of planktonic
foraminifera in Jorband area show the warm marine environment dominant during
early to late Campanian and it could be correlating by tropical and subtropical
biozones. The warm condition converted to rapid cooling exactly in CampanianMaastrichtian
boundary. This rapid changing in temperature was not important
effecting in extinction species but make important differences in number of
species. Increasing the heterohelicids populations associated with surface dwellers
and decreasing of globigerinids show the rapid regression in Jorband area in the
Campanian-Maastrichtian boundary. The cooler condition is dominated during
early Maastrichtian, whereas heterohelicids were associated by rugoglobigerinids
and globigerinelloids. In the late Maastrichtian, abundances of double-keeled
species show high sea level and warmer condition dominated in Jorband area in
Planoglobulina brazoensis zone (CF5) and Racemiguembelina fructicosa zone
(CF4).
