|mhorn||Дата: Tuesday, 16.10.2012, 15:45 | Сообщение # 1|
|Hjálmarsdóttir H.R., Nakrem H.A., Nagy J. (2012) Foraminifera from Late Jurassic – Early Cretaceous hydrocarbon seep carbonates, central Spitsbergen, Svalbard – preliminary results // Norwegian Journal of Geology, Vol 92, P.157-165. |
Mixed calcareous-agglutinated benthic foraminiferal assemblages have been obtained from five hydrocarbon seep carbonate structures in the upper Slottsmøya Member (Agardhfjellet Formation) in central Spitsbergen, Svalbard. The composition of the agglutinated component is comparable to faunas previously described from the surrounding dark shales of the Slottsmøya Member, as well as from deposits of Arctic Russia and other areas of the Boreal Realm. Calcareous foraminifera are observed only in thin-sections. The foraminifera date the hydrocarbon seep bodies as Late Volgian – Late Ryazanian; an age determination in part slightly divergent from ammonite datings previously recorded from these carbonates. This is the first systematic report of foraminifera from seep structures developed at the Jurassic-Cretaceous transition.
Middle Jurassic - Lower Cretaceous ammonites & aptychi