Keywords : Paleoecology


Biostratigraphy by Calcareous Nannofossils and Paleoecology by Ostracoda of Tanuma Formation, Central Iraq

Omar A. Al-Badrani; Sanad A. Al-Khashab

Iraqi National Journal of Earth Sciences, 2013, Volume 13, Issue 2, Pages 33-46

Forty three samples of limestone and shales from Tanuma Formation obtained from East Baghdad well (No. 11) at depths (2067 - 2177 m.) about 110 m. in thickness. Details investigated carried out identify twenty species of calcareous nannofossils, sixteen described from other region and four left open name because of rare and not clear samples. Furthermore, twenty four species of ostracodes belonging to fourteen genera were recorded, these are: Bairdia, Brachycythere, Curfsina, Cythereis, Cytherella, Cytherelloidea, Dolocytheridea, Ovocytheridea, Paracypris, Protocythere, Pterygocythere, Schuleridea, Spinoleberis, Veenia.
The recorded calcareous nannofossils assemblages permits to recognized two biozones these are:

2- Micula cf. decussata Interval Biozone (CC14).

1- Marthasterites furcatus Interval Biozone (CC13).
On the basis of biocorrelation with previous works Coniacian age confirmed for the Tanuma Formation at the studied section. The analysis of the ostracode fauna led to conclude that the palaeoecology of the Tanuma Formation in this section is shallow marine environment at depth about 200m in the neritic zone with warm water, under normal marine water salinity.

Paleoecology of Garagu Formation and the Upper Part of Ratawi Formation (Lower Cretaceous) of Central Iraq

Jinan M. Al-Basher; Sanad A. Al-Khashab; Salih K. Khalaf

Iraqi National Journal of Earth Sciences, 2011, Volume 11, Issue 1, Pages 1-14

Ostracode assemblages from Garagu and Ratawi Formations (Lower Cretaceous) from Makhul-2 (Mk-2) and East Baghdad-1 (EB-1) boreholes were studied in details, leading to the conclusion that Garagu Formation deposited under shallow marine sublittoral environment with normal salinity and warm water, while Ratawi Formation deposited in shallow marine environment with anoxic environments.

Palynostratigraphy and Paleoecology of the Upper Part of Akkas Formation in Borehole KH5/1in the Western Iraqi Desert

Noha D. Al-Sawaf; Amer D. Nader

Iraqi National Journal of Earth Sciences, 2008, Volume 8, Issue 2, Pages 64-81

Fourteen sample from the stratigraphic interval (1330-1600m.) in the borehole KH5/1 were studied palynoogically. The samples yielded well preserved and diversified palynomorphs except one sample at depth (1330m.) was barren.
Identification of (54) species of acritarchs belong to (29) genera and (16) species of Chitinozoans belong to (9) genera, (16) species of miospores belong to (13) genera and (6) species of Scolecodont belong to (4) genera was the conclusion of this study.
Comparision with similar palynomorphs in different parts of the worlds indicates clearly Upper Silurian (Ludlow) age for the samples studied. The Palynomorphs and especially the acritarchs reveal that the studied section was deposited in near