S. D. Nikolaev* and N. S. Os’kina**
* Geographical Department, Moscow State University, Moscow, Russia
**Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia
Received June 2, 1998
Abstract—Distribution of the types of stratification over the area of the oceans in the Northern Hemisphere in
the past was reconstructed on the basis of the types of vertical temperature distribution in the surface water mass
by joint use of isotopic-oxygen and foraminiferal methods. It was shown that, during the Neogene, the number
of types of thermal stratification of the surface water mass increased from three at the beginning of the Early
Miocene (foraminiferal zone N4) to four at the end of the Early Miocene (zone N8). All five types of thermal
stratification were found in the Pliocene. Complication of thermal stratification took place in parallel with dif-
ferentiation of the climatic zones distinguished by the micropaleontological method. The types of thermal strat-
ification of the surface water mass in the Pliocene are similar to their present-day analogs. The vertical profiles,
differing from the present-day ones in temperatures, though generally similar to them, are found along with
closely similar profiles.
Pleiades Publishing home page | journal home page | top
If you have any problems with this server, contact webmaster.