The aim of this study is to investigate the sedimentation environments and diagenetic processes of the Ibrahim Formation (Oligocene-early Miocene) in Zurbatiya, eastern Iraq. The Ibrahim Formation is comprised mostly of clayey micrite and skeletal grains composed of planktonic foraminifera, calcispheres, radiolaria, and benthic foraminifera. Glauconite and pyrite were documented in some restricted zones of this formation; they reflect quiet and reducing conditions. Radiolaria were identified in Late-Oligocene which was not known previously at this age regionally in carbonate formations of the Arabian Plate (AP). Mudstone, wackestone, and planktonic foraminiferal wackepackstone are the main microfacies that are affected by dissolutio
... Show MoreThe sequence in the upper part of the Balambo Formation is composed mainly of limestone alternating with marly limestones and dark grey shale in the Bosheen section (eastern Sulaymaniyah, northeastern Iraq) and has been studied in terms of its rare earth element (REE) content. The REEs are very low compared to modern marine sediments. They are depletion in LREEs, and enrichment in HREEs and (La/Yb)N in the studied rocks, indicating that these sediments retained the REEs pattern of marine waters. The negative Ce anomaly reflects direct sedimentation from marine waters under anoxic conditions with the contribution of terrigenous clays. The positive correlation of ∑REEs with Al, Ti, and Y, and the negative correlation of ∑REE
... Show MoreThe study of the geochemical characterization of sandstone rocks contributes to understand the nature of the source rocks, their tectonic setting and the effects of paleoclimate and paleo-weathering. Accordingly, twenty sandstone samples from the red sandstone units of the Gercus Formation were collected from the northeastern limb of Safin Anticline at Shaqlawa Area – Northern Iraq. The studied sandstone samples show depletion in major, trace elements contents, except for CaO, MgO and Ni, Co and Cr respectively, and general depletion in the rare earth elements (REE) contents. Major element geochemistry indicates that the red bed sandstones of the Gercus Formation are of an oceanic island arc (OIA) tectonic setting. On the other
... Show MoreSynthesis of sedimentologic, paleocurrent, and organic geochemistry data of the Lower Permian Ga’ara Formation from the Western Desert, western Iraq, shows good hydrocarbon potentiality and deposition by high sinuosity and mixed-load channels, likely by a meandering river system. The Ga’ara Formation includes kaolinitic mudstone beds of various colors and channelized quartzitic sandstone beds. Based on the lithofacies identification, five lithofacies associations have been recognized: channel-floor, point-bar, abandoned channel plug, crevasse splay, and interchannel flood basin. In addition, the paleocurrent analysis and sandstone percentage map indicate a variation of the paleoflow spatially and temporally with a general di
... Show MoreChar formation is subdivided into three lithological types according to the percentage of detrital quartz and calcite (micrite and sparite), through the petrographic study of 13 thin sections collected from a section at Wadi Al-Ratgha (west of Al-Qaim, Iraq Western Desert). The three rock units are: Limy sandstone, limestone and sandy limestone. Depending on the mean gain size of detrital quartz and degree of sorting and the type of matrix, Ghar Formation can be classified in to three types, i. e. off-shore sediments with low energy environment, near shore sediments with high energy environment and mixed sediments with transitional energy environment. This is due to local transgression and regression of sea level at late lower Miocene du
... Show MoreAn 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
... Show MoreThe 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 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
The present study is focused upon the sedimentology and basin development of the Jeribe and Fatha Formations by using the field observations and microfacies analysis. The area of study situated in the Zurbatiyah area to the south of the Shur sharin valley about 21 km northeast of Badrah city to the southeast of Baghdad. This area lies within the Zagros foreland basin, and located between the Zagros mountains at the northeastern and the Arabian shield at the southeastern.
The studied succession which including the Jeribe and Fatha Formations were deposited within four associated facies for the Jeribe Formation and three for the Fatha Formation, as shown below: -
Jeribe Formation
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