Keywords : Eocene


Planktic Foraminiferal Biostratigraphy of the Upper Part of the Damlouk Member, Ratga Formation, Western Desert, Iraq

Imad Ghafor; Basim Al-Qayim

Iraqi National Journal of Earth Science, 2021, Volume 21, Issue 2, Pages 49-62
DOI: 10.33899/earth.2021.170385

The basinal part of the Damlouk Member upper sedimentary cycle of the Ratga Formation exposed in the Qaim area of the Iraqi western desert is examined. The studied section consists of marlstone, marly and phosphatic limestone, and planktic foraminifera-rich limestone beds. Detailed study of the planktic foraminiferal assemblages of these rocks revealed the occurrences of (30) species belonging to (11) genera. The stratigraphic distribution of these species permits the recognition of three biozones. These are from the lower to upper part of the section: - Acarinina bullbrooki Zone, (Middle Lutetian), Morozovelloides lehneri Zone, (Late Lutetian), Globigerinatheca semiinvolutaHantkenina alabamensis Zone, (Early Bartonian). These zones indicate that the studied section of the Ratga Formation (Damlouk Member) is of Middle-Late Lutetian to Early Bartonian age. These biozones are correlated with different local and regional studies.

Paleocene -Eocene Ostracoda From Selected Wells in West, North and Central Iraq

Nisren M. Aziz

Iraqi National Journal of Earth Science, 2013, Volume 13, Issue 2, Pages 47-66
DOI: 10.33899/earth.2013.79661

Twenty two ostracoda species belonging to eight genera were described
from Avanah ,Sinjar, Khurmala, Aaliji, Akashat and Jaddala Formations, (Paleocene-Eocene) of North, West and Central Iraq of which four species are new, Abyssocypris zumarensis, sp.inov., Argilloecia heijranensis sp. nov., Argilloecia baajensis sp. nov., Schizocylhere anbarensis sp. nov. The identified species
shows strong affinities to those in India, North Africa and the Middle East (Southern New Tethys).

Biostratigraphy of Planktonic Foraminifera of Jaddala Formation (Eocene), Bara area, Northwestern Iraq

Majid M. Al-Mutwali; Inas S. Al-Sharbaty

Iraqi National Journal of Earth Science, 2013, Volume 13, Issue 2, Pages 67-84
DOI: 10.33899/earth.2013.79662

A surface section of Jaddala Formation was studied near Bara Village in the western plunge area of Sinjar anticline northwestern Iraq . The sequences under study consist of marl, marly limestone and limestone beds. Detailed study of planktonic foraminifera revealed (38) species belonging to (14) genera, the stratigraphic distribution of these species permits the regognition of five zones, these are: Morozovella aragonensis Zone, Acarinina pentacamerata Zone, Acarinina bullbrooki Zone, Globigerinatheka subconglobata Zone and Acarinina collactea Zone. These zones indicate that Jaddala Formation is of Early - Middle Eocene age.

The Effect of the Mineralogy and Geochemistry of Pila Spi Rocks(M.U.Eocene) at Jabal Ain Al-Safra on the Spring Waters

Iraqi National Journal of Earth Science, 2008, Volume 8, Issue 2, Pages 82-90
DOI: 10.33899/earth.2008.5478

The major part of the exposed anticline of Jabal Ain Al – Safra consists of Pila Spi Formation (M.U.Eocene) and contains five water springs (Ain Al– Safra, Squf, karawan, Semmak Baadra).
The Pila Spi rocks consist of different proportions of calcite and dolomite at different areas, within the eastern limb of Jabal Ain Al– Safra anticline. Grain size, joints densities and fractures are also different.
The present study has concluded that Ain Al– Safra waters compared with other spring waters within the area have high concentration of the ions of (Ca, Mg, Mn, Fe, Cu, Co ) especially manganese (Mn).this is possibly because the under ground waters before reaching Ain Al– Safra spring pass through relatively thick gently dipping rocks, rich in calcite and have fine grain size and also pass tow layers of marl interbedded with carbonate rocks.
These conditions plus the pressure of CO2 and the effect of the (pH) value allow water to dissolve carbonate minerals and becomes relatively enriched in the above ions.

Sequence Stratigraphy of Gercus Formation (Middle Eocene) in Sulaimaniya Area, Northeastern Iraq

Bakhtiar M. Ameen

Iraqi National Journal of Earth Science, 2006, Volume 6, Issue 2, Pages 23-32
DOI: 10.33899/earth.2006.36387

The Middle Eocene Red Beds known as typical facies of Gercus Formation in north and northeastern Iraq. In the field they cropout as red succession of claystone, lensoidal sandstones and conglomerates. Tectonically the beds are exposed in the folded area of the Zagros Fold-Thrust belt of northeastern Iraq. The whole formation consists of major low stands system tract within stratigraphic record of Tertiary which belongs to 2nd order sea level change. This major lowstand system tract is divided into two depositional sequences named upper and lower sequences which are modulated within 3rd order sea level change. About 90% of its thickness is deposited in the lower sequence, and 10% in the upper one. The lower sequence bounded by SB1 and SB2 from the bottom to the top respectively. It is comprised of SMST, TST and HST. Only the LST of the upper sequence is represented in the Gercus Formation, while the other systems tracts are possibly included in the carbonate of Pila Spi Formation. The SMST consists of alternation of red claystone and marl which are locate at the top of Khurmala Formation.
The TST (middle part of Gercus Formation) is composed of grey marl and laminated marly limestone. The HST consists of alternation of red claystone, laminated sandstone and calcareous shale.
The LST consists of 1-4m of rounded and sorted conglomerate located at the upper part of Gercus Formation. This system tract is underlain by an erosional unconformity. The inferred depositional environment is most possibly braided delta plain which is prevailed by fresh water influx and flooding by marine water. This is shown in the field by mud cracks, marl marine sediments and laminated sandstone which deposited in upper flow regime.