Calciturbidites are similar to siliciclastic turbidites in structure, texture, basin physiography and processes of deposition; nevertheless, their clasts (grains) are carbonate minerals. Turbidity currents transport carbonate grains from carbonate source areas and coastal areas to the deep basins after passing the shelf (peri-platform). These currents are triggered by short-lived catastrophic events, such as tsunamis, earthquakes, marine slides, and typhoons. The Late Cretaceous Zagros Foreland and Hinterland in NE-Iraq (Kurdistan Region) was an active source for the shedding of voluminous sediments to the deep basin of Zagros Foreland Basin. During late Campanian, Shiranish Formation was deposited in the foreland basin; it occurs in the

Ostracode assemblages have been utilized for the study of the paleoecology of
the Maastrichtian – Upper Eocene succession (Hartha, Shiranish, Aaliji, Kolosh,
Jaddala and Avanah formations) in North and Iraq, represented by five sections,
including four boreholes, Anah well-2, Mityaha well-1, Makhul well-2,
Chemchemal well-2 and Jabel Sinjar outcrop section. According to the different
environmental factors affecting on the ostracode ecology, such as salinity, depth,
temperature, oxygenation, substrate and food supply; and depending on the
distribution of ostracode assemblages within the studied sections, nine ecofacies
have been recognized indicating shallow brackish or brackish- marine water, neritic
marine,

This study is achieved in the local area in Eridu oil field, where the Mishrif Formation is considered the main productive reservoir. The Mishrif Formation was deposited during the Cretaceous period in the secondary sedimentary cycle (Cenomanian-Early Turonian as a part of the Wasia Group a carbonate succession and widespread throughout the Arabian Plate. There are four association facies are identified in Mishrif Formation according the microfacies analysis: FA1-Deep shelf facies association (Outer Ramp); FA2-Slope (Middle Ramp); FA3-Reef facies (Shoal) association (Inner ramp); FA4-Back Reef facies association. Sequence stratigraphic analysis show there are three stratigraphic surfaces based on the abrupt changing in depositional

This study includes structural and stratigraphic interpretation of 3D seismic reflection data for Zubair Formation (L. Cretaceous) within Al-Akhadeir area, southwestern Iraq (Karbala Governorate). Depending on the 3D seismic reflection interpretation process, and based on the synthetic seismogram  and well logs data, two horizons were identified and selected (top and base Zubair  reflectors). These horizons were followed up over the entire area in order to obtain structural and stratigraphic settings. TWT, depth, and velocity maps for the base and top Zubair Formation were constructed. From the interpretation of these maps and based on the seismic section, the study concluded that there are some enclosures that represent anticl

The Miocene succession of western and southern Iraq is represented by the
Euphrates, Ghar, Jeribe, Nfayil, Fatha, and Injana formations. The Euphrates
Formation (Early Miocene) consists mainly of shallow marine facies; it`s equivalent
the Ghar Formation (Early- Early Middle Miocene) is represented by continental
clastic facies. The Jeribe Formation (Early Middle Miocene) represents shallow
marine environment. The Nfayil Formation (Middle Miocene) also of shallow marine
environment, it`s equivalent the Fatha Formation is represented mainly by supratidal
marine environment. The Injana Formation (Late Miocene) represents the clastic
continental facies.
The studied succession was highly affected by many diagene

Sequence stratigraphic cycle of Cenomanian-early Turonian is composed of (Ahmadi, Rumaila, and Mishrif) formations, which is bounded at top and base by unconformity surfaces. The lithofacies of this cycle in the southern Iraq indicate a normal lateral change facies from shallow water facies through deeper water and open marine sediments, Ahmadi Formation (early Cenomanian) characterized by open marine sediments during the transgressive conditions, and passes up into deep basinal sediments (Rumaila Formation) by conformably surface.

     Rumaila Formation (middle Cenomanian) was deposited in the deeper part of the intrashelf basin, which comprises of a mainly basinal sediments, and includes an abundant of open

The studied succession is deposited during late Berriasian-Aptian interval, which is represented by the Zubair, Ratawi, Yamama formations. The present study includes stratigraphic development and basin analysis for 21 boreholes (Rachi-1, 2; Rifaei-1, Diwan- 1; Ratawi-1, 2; Halfaia-5; West Qurna 12, 15; Nahr Umr-7,8; Zubair-47,49; North Rumaila- 72, 131, 158; Suba-7; Majnoon-2, 3 and Luhais-2, 12) distributed within 13 oil fields in the southern Iraq. The back-stripping process determined the original direction of basin depocenter for the studied succession. The Yamama basin in the study area stretches from southeast to southwest with single depocenters, it was located in the southeast of the study area near wells Mj-2, Mj-3.NR-8 and

The distributions of rivers, back swamps, delta, and ancient marine shore line of Southern Mesopotamia during Late Pleistocene – Holocene have been studied depending on the ostracoda and foraminifera assemblages as ecological indicators to determine the ecofacies and paleosalinities, which diagnose different depositional environments. The data are collected from 86 boreholes (including 12 deep boreholes), covering almost the entire Southern Mesopotamia.
Rates of sedimentation are calculated and corrected for compaction in this study, relative to previously measured C14 dating by some authors, for the marine and non- marine (Ur Flood) deposits.
Those rates of sedimentation found in this study are varies from a borehole to another,

The middle Cenomanian – early Turonian Mishrif Formation, a major carbonate reservoir unit in southern Iraq, was studied using cuttings and core samples and wireline logs (gamma‐ray, density and sonic) from 66 wells at 15 oilfields. Depositional facies ranging from deep marine to tidal flat were recorded. Microfacies interpretations together with wireline log interpretations show that the formation is composed of transgressive and regressive hemicycles. The regressive hemicycles are interpreted to indicate the progradation of rudist lithosomes (highstand systems tract deposits) towards distal basinal locations such as the Kumait, Luhais and Abu Amood oilfield areas. Transgressive hemicycles (transgressive systems tract deposits)

An integrated lithofacies and mineralogical assemblage was used to describe a depositional model and sequence stratigraphic framework of the Maastrichtian–Danian succession in the Western Desert of Iraq and eastern Jordan. Fifteen lithofacies types were grouped into three associations recognized in a distally steepened ramp characterized by an apparent, distinct increase in a gradient paleobathymetric deepening westward. The clay and nonclay minerals are dominated by smectite and palygorskite, with trace amounts of kaolinite, sepiolite, illite and chlorite. Meanwhile, quartz, calcite, dolomite, opal CT (Cristobalite - Tridymite), and apatite are the main nonclay minerals. The widely dominated smectite in the Western Phosphatic Basin of Ir