..., the Cretaceous Aptian and Cenomanian intra-shelf basins formed mainly as a consequence of environmental/climatic disturbances associated with global oceanic anoxic events. During these times of global climate stress carbonate sedimentation was unable to keep up in areas with relatively high subsidence rates...

... constraint stratigraphy core sample anoxic event shuaiba formation upstream oil & gas nannofossil hardenbol sediment nannoconus bucheri reservoir characterization nannoconid crisis nannoconus truitti calcareous nannofossil assemblage structural geology system tract well 3...