Among these benthicand planktonic for aminifera are the most diverse, biostratigraphically
important and comparatively well studied (Jones, 1961; Afzal, 1996; Warraich et al., 2000).
The boundary between the Rakvere and Nabala RSs is biostratigraphically
easy to recognize by the presence of the chitinozoan zonal species Armoricochitina reticulifera (Grahn) in the lowermost Montu or Paekna Fms (Mannil & Meidla 1994; Nolvak et al.
The limestones sampled from the studied exposures of the Fila de Cal Formation show a total of eight different microfacies types (MF1 to 8, Tables 1 and 2) and three biostratigraphically
successive larger foraminiferal assemblages.
To date no biostratigraphically
useful fossils have been found in the Dighton Conglomerate and its age is inferred from its stratigraphic relationship with the Rhode Island Formation.
Within these facies, at 15 meters from the base of the succession, appears Gevanites (Curionii Zone, Brack et al., 2003; Brack et al., 2005), which serves to date biostratigraphically
The Jahrum formation biostratigraphically
has been studied by James, and Wynd, .
Some of these sites reflect a Rancholabrean age based on presence of Bison, while others cannot be biostratigraphically
The age of the Woodbine Formation was established biostratigraphically
by Kennedy and Cobban (1990) using ammonites from marine members in the lower part of the formation.
From these diverse assemblages, nine species are of great importance, either biostratigraphically
or biogeographically, or are rare Great Plains taxa.
Most are biostratigraphically
based, but other criteria have been used, such as the iridium spike at the base Cenozoic, the carbon isotope anomaly at the base of the Eocene, and a specific Milankovitch cycle at the base of the Pleistocene.
Regardless of the small thickness of the Leetse Formation in the Saka section, its sequence is biostratigraphically
the most complete on the North Estonian Klint.
O date it biostratigraphically
. No palynomorphs were recovered.