Main Subjects : Stratigraphy


Ostracoda Assemblages of the Hartha Formation (Late Campanian - Early Maastrichtian) from Balad (8) well, Central Iraq

Muhanad Zuhair Hamid; Ibrahim Younis Al-Shareefi

Iraqi National Journal of Earth Science, 2022, Volume 22, Issue 1, Pages 15-37
DOI: 10.33899/earth.2022.174663

Fundamentally, the current study is concerned with the investigation and diagnosing of Ostracoda fossils from the subsurface section of the Hartha Formation (Late Campanian - Early Maastrichtian) from (Ba-8) well at central Iraq. Fifty-nine Ostracoda species belonging to (29) genera/ subgenera from (13) families are diagnosed and classified to their ranks according to the standard systematic paleontology. Whereat (57) species are attributed to species previously described from local and regional studies. Two species are left under open zoological nomenclature basically because of lack of specimens. As a result, the study inferred that the species diagnosed in the Hartha Formation belong to the Late Campanian - Early Maastricht. As These species are very similar in terms of the external appearance and geologic age to the same species that were compared with them and which were previously described in the regions of East, West, and North Africa as well as the Arabian Gulf region.

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.

Reservoir Characterization of the Middle Cretaceous Mishrif Formation in the Buzurgan Oilfield, Southern Iraq

Muneef Mohammed; Hameed Salih; Kadhim Mnaty

Iraqi National Journal of Earth Science, 2021, Volume 21, Issue 2, Pages 63-77
DOI: 10.33899/earth.2021.170388

The Mishrif Formation is considered the main oil reservoir in the Buzurgan oilfield, southern Iraq. This study aims to characterize and evaluate the reservoir properties of the Mishrif Formation based on the interpretation of well logs data. The logs data for six wells have been analyzed and interpreted by using Techlog 2015.3 software. The lithology of the Mishrif Formation was determined by using the M-N cross plot method based on the interpretation of density, neutron, and sonic logs. The results showed that the Mishrif Formation is mainly composed of limestone. The shale volume in the Mishrif Formation has been estimated from the gamma-ray log. The results illustrated that the shale volume is about 20% of the bulk volume, and may increase to reach the highest value at the upper part of the MA unit of the formation. The porosity of the Mishrif Formation was calculated based on the interpretation of neutron, density, and sonic logs. To achieve accurate values of porosity, the log-derived porosity has been correlated with the core-derived porosity, and the comparison showed a good correlation between the two types of porosity. The results showed that the Mishrif Formation is characterized by low to medium porosity (about 5% to 18%). The secondary porosity of the formation is most dominant in the MB21 unit compared with the other stratigraphic units of the Mishrif Formations. This indicates that the MB21 unit was affected by the diagenesis processes. The MB21 unit of the Mishrif Formation represents the most dominant reservoir because it was delineated by high effective porosity and high oil saturation.

Some records Ostracod species of genus Paijenborchellina from the Middle Miocene Fat'ha Formation, Eastern Butmah Anticline, Northwestern Mosul City, Iraq

Maha Mohammed; Ibrahim Al-Shareefi

Iraqi National Journal of Earth Science, 2021, Volume 21, Issue 1, Pages 1-19
DOI: 10.33899/earth.2021.170377

Through a comprehensive taxonomic study of the ostracoda fossils in Fat'ha Formation in the stratigraphic section exposed within the eastern limb of Butmah anticline northwestern Mosul city, several genera and their belonging species of ostracoda have been identified from this previously unexamined section in terms of fossils. However, the focus in this research is on the genus Paijenborchellina and its species as it indicates an important environmental, age and geographical indications Six species belonging to this genus have been diagnosed as follows:
Paijenborchellina  keeni Gammudi & Keen, Paijenborchellina  libyca Szczechura,
Paijenborchellina cf. kausalis Khalaf, Paijenborchellina (Eupaijenborchella) iraqensisKhalaf, Paijenborchella (Eupaijenborchella) pronaLyubimova and Guha,andPaijenborchella (Eupaijenborchella) royi Khosla.
 

Geological history, Ichnofacies and Sequence Stratigraphy of the Eocene – Oligocene Boundary at Sinjar Area, Northwestern Iraq

Majid Al-Mutwali; Hiba Al-Rubai

Iraqi National Journal of Earth Science, 2021, Volume 21, Issue 1, Pages 27-45
DOI: 10.33899/earth.2021.170380

Three outcrop sections for the Eocene- Oligocene boundary have been studied in Sinjar anticline northwestern Iraq. This study includes the lithostratigraphy, biostratigraphy and the identification of trace fossils and related ichnofacies in order to report the geological history of this boundary in the frame of sequence stratigraphy. Jaddala Formation, which is composed of marl and marly limestone, represents deep (outer shelf-upper bathyal) Eocene facies, Palani and Tarjil formations represent deposition in deep basinal environments during Early and Late Oligocene sequences.
    The Eocene- Oligocene boundary in Sinjar area represents a disconformity surface, where the deposition ceased in the Middle Eocene (Lutetian) at the end of Jaddala Formation, forming  the firmground  Glossifungites Ichnofacies which embrace  Thalassinoides ichnotaxa in Jaddala section, and the hardground  Trypanites Ichnofacies  in Sharafiddin section, while at Sinjar section, a chalky limestone bed deposited at the Early Oligocene (Rupelian) Palani Formation representing Skolithos Ichnofacies.
    A rapid wide transgression took place at the end of Early Oligocene (Rupelian) leading to the deposition of Palani Formation, and continued through the Late Oligocene (Chattian) leading to the deposition of Tarjil Formation.

The Study of Lithology by Using the Cross-Section Profiles of The Logs of Shiranish and Mushorah Formations in Ain Zalah and Butmah Fields, Northwestern Iraq

Faris Hassan; Wissam Mohamed; Wafaa Yunus; Abdul-Salam Salih

Iraqi National Journal of Earth Science, 2021, Volume 21, Issue 1, Pages 17-26
DOI: 10.33899/earth.2020.170378

This study deals with the determination of lithology in the Shiranish and Mushorah Formations in wells (Az-24, Az-29, and But-15). The graphical representation of the neutron porosity log (NØ) and the bulk density ρ)b(, shows that the Shiranish (Late Campanian – Early Maastrichtian) and Mushorah (Early Campanian) Formations consist of limestone and dolomite, as well as shale. The proportion of dolomite and chert increases at the expense ofcalcite in the Mushorah Formation. Also, the graphical representation results of the M-N profile for each well indicate that the limestone of the Mushorah Formation were affected by the dolomitization with the development of secondary porosity. Moreover, the limestones were suffered silicification in the form of chert nodules. The MID profile, used in this study to determine the mineralogy gives better and more precise results than that of the M-N profile. The results showed that the dominant minerals are calcite in the Shiranish Formation while dolomite and quartz in the Mushorah Formation, regardless of the gas effects within the studied wells.

Biostratigraphy and Sequence Stratigraphy and Depositional Environment of Kolosh Formation in Dohuk Area, Northern Iraq

Saif Al-Khalaif; Majid Al- Mutwali

Iraqi National Journal of Earth Science, 2020, Volume 20, Issue 2, Pages 18-42
DOI: 10.33899/earth.2020.170362

The present study deals with biostratigraphy, depositional environment and sequence stratigraphy of Kolosh Formation in two sections of Bekher anticline, northeastern Iraq by using the planktonic and benthonic foraminifera. Therefore, (48) species of planktonic foraminifera belonging to (14) genera and (34) species of benthonic foraminifera belonging to (19) genera have been recognized. The detailed planktonic foraminiferal investigation permits the recognition of seven well defined biozones and three subzones; they indicate that Kolosh Formation extends from the Early Paleocene (Danian) to Late Paleocene (Thanetian) age. The depositional environment of the formation was studied throughout relying on the variation in the diversity of planktonic forminifera, as well as throughout the ratio of the planktonic foraminifera to the whole mass of foraminifera, and the ratio of planktonic forminifera to the benthonic formiminifera. The lower part of the formation represents the upper bathyal environment, while the middle part deposited within the outer shelf environment, then deposition basin became within the middle shelf area in the upper parts of the formation.
Sequence stratigraphic analysis for the studied sections of Kolosh Formation  delineated three sequences which is interpreted as 3rd order sequences, and it is found that the deposition of Kolosh Formation in the Badi section had been occurred in shallower level for most sedimentation intervals compared to the Linwa section which represents a somewhat deeper marine environment.

Paleoenvironmental Study of Khurmala Formation by Ostracoda in Shaqlawa and Dohuk area, Northern Iraq

Mahfoudh Al-Hadeedy; Saleh Khalaf

Iraqi National Journal of Earth Science, 2020, Volume 20, Issue 2, Pages 148-164
DOI: 10.33899/earth.2020.170375

   A detail paleoenvironmental study of ostracods fauna to investigated the paleoenvironment of Khurmala Formation for two section Northern Iraq; the first (Hjran section) lies near Shaqlawa city, and the second (Dohuk section) lies near Dohuk city. Based on ostracods study conclude that Khurmala Formation were deposited in shelf environment, about (30 – 200) meter in depth.

Sedimentological and Biological indicators of oceanic anoxic events (1d) inside upper Balambo Formation, L. Albian, northeastern Iraq

Falah Al-Miamary; Ali Al-Jubory; Safwan Al-Lhaebi

Iraqi National Journal of Earth Science, 2020, Volume 20, Issue 2, Pages 86-104
DOI: 10.33899/earth.2020.170372

The studydeals with succession from the upper part of the Late Albian Balambo Formation which are composed of fine-grained dark gray to black calcareous shale, limestone and marly limestone rich in sedimentary structures such as lamination, fissility and platy structures. Microfacies analysis revealed that mudstone, wackstone and few of packstone are the main facies in the studied succession. The studied rocks generally are rich in organic matter and pyrite in addition to dominance of radiolaria, sponge spicules and foraminifera with elongated champers maybe “Schackoina” genus. All these characters indicate deposition in marine conditions with reduced or absent-oxygen condition that relate to oceanic anoxic event (1d).

Planktonic Foraminifera Biostratigraphy of Shiranish Formation in Piramagroon Anticline, NE Iraq

Ahmed Al-mutiwty; Abdullah Shihab

Iraqi National Journal of Earth Science, 2020, Volume 20, Issue 2, Pages 43-63
DOI: 10.33899/earth.2020.170369

67 planktonic foraminiferal species were identified from the Shiranish Formation. On the basis of the stratigraphic distribution of the planktonic foraminiferal assemblages recognited of six biozones within the Shiranish Formation representing an age ranging from Middle Campanian – Early Maastrichtian, these zones are from older at base:
6 -Planoglobulina acervulinoides Interval Zone.
5 - Contusotruncana contusa Total Range Zone.
4 -Gansserina gansseri Interval Zone.
3 - Globotruncana aegyptiaca Interval Biozone.
2 -Globotruncanella havanensis Interval Biozone.
1 -Globotruncana ventricosa Interval Biozone

Biostratigraphy and Systematic Palaeontology of Late Cretaceous Heterohelicidae Foraminifera from Kurdistan Region North-eastern Iraq

Rawand Jaff; Fadhil Lawa

Iraqi National Journal of Earth Science, 2020, Volume 20, Issue 2, Pages 33-63
DOI: 10.33899/earth.2020.170360

The biostratigraphical importance and systematic palaeontology of Early Turonian to Early Maastrichtian Heterohelicidae Planktic foraminifera from Kurdistan region, NE Iraq are described. Some 24 species from 11 genera are recorded. Species abundance and diversity increase from the Early Turonian to Early Maastrichtian, perhaps signifying cooler sea temperatures in the Arabian sector of the Tethys Ocean during the Early Maastrichtian. Despite the long biostratigraphical ranges of some species, the importance of the biserial and multiserial Planktic foraminifers in Late Cretaceous biostratigraphy is emphasized. From a biostratigraphic perspective, heterohelicids are important for the definition of the Campanian-Maastrichtian boundary in Kurdistan region, with Planoglobulina species being especially important in this respect, as they are in Iran, Turkey and North Africa.

Sedimentary Environment of Naokelekan Formation (Late Oxfordian – Early Kimmeridgian) of Selected Surface Sections from Northern-East of Iraq

Zainab Al-Malaa; Rafi’ Al-Hmeedi

Iraqi National Journal of Earth Science, 2020, Volume 20, Issue 1, Pages 31-55
DOI: 10.33899/earth.2019.170330

The Naokelekan Formation (Late Oxfordian - Early Kimmeridgian) was studied at three surface sections (Rowanduz, Ranya and Sargelu), in northeastern Iraq. The Formation is composed mainly of alternating sequence of thin- bedded limestone, dolomitic limestone and bituminous black shales. Streaks of calcite veins, chert nodules and bituminous stylolite are present. Traces of Ammonite molds, flat, wavy to domal stromatolites are also present.
The Petrographic study showed that the formation contains various petrographic components represented by Ammonites, pelecypods, gastropods, calcispheres, planktonic and benthonic foraminifera, ostracods, stromatolite, radiolaria and bryozoans, pellets and intraclasts, in addition to the groundmass of micrite and microspars. The rock successions were extensively affected by many diagenetic processes and their effect is most pronounced pronounced on textural properties of these rocks. The dolomitization seems to be one of the most important diagenetic processes recognized. The other processes are; compaction, micritization, bioturbation, authigenic minerals, cementation, neomorphism, dissolution, fractures and veins, silicifaction, replacement and dedolomitization.
The detailed facies analysis reveals that the rock succession consists mainly of three microfacies and two lithofacies type. The main microfacies include lime mudstone,wackestone and packstone.  Where the lithofacies comprise limestones and shales which are represented by four sub lithofacies. The overall characters of these facies indicate that the formation was deposited in two different environments; (1) shallow marine sub tidal environment at the lower part and upper part respectively. (2) Outer shelf in a euxinic environment at its middle part.

Petrology and Genesis Development of the Hardground at the Uppermost Part of Bekhme Formation, Dohuk Area, Northern Iraq

Nidhal Yahya; Salim Hussain

Iraqi National Journal of Earth Science, 2020, Volume 20, Issue 1, Pages 1-19
DOI: 10.33899/earth.2020.170287

Hard ground at the uppermost part of Bekhme Formation is studied at three outcrop sections located in the Dohuk area, northern Iraq, and it is found that it consists of two distinct facies associations. The first includes limestone beds that comprise the hard ground and its omission surfaces. The second consists of limestone, marly limestone, and marl, which is interbedded with successive hard ground. The overall characters of these two facies associations indicate that deposition took place in a carbonate ramp setting. Vertical variations of sedimentary components suggest that the hard ground was developed by three successive stages. These are the end of shallow carbonate sedimentation and the drowning of the platform, the formation and modification of hard grounds, and finally the deposition of pelagic carbonate sediments of the Shiranish Formation.
The second stage is characterized by intercalations of continuous depositional and biological processes. These include bioturbation, bioencrustation, and secondary mineralization in addition to other early and late diagenetic processes. The depositional area had been affected by tectonic drowning of carbonate ramp with a wide gradual marine transgression associated with a period of local marine regression that is, in turn, responsible for deposition, transportation, redeposition, submarine erosion and formation of hard grounds. Thus, the hard ground zone represents drowning unconformity surfaces between Bekhme and Shiranish formations through the Campanian- Maastrichtian boundary.

Paleoecology and Statistical Study of Ostracoda, Fat'ha Formation (Middle Miocene) from Bazian Anticline, Al- Sulaymaniyah Area, Kurdistan Region, Iraq

Zahida Al-Hadithi; Nisreen Aziz

Iraqi National Journal of Earth Science, 2019, Volume 19, Issue 2, Pages 119-135
DOI: 10.33899/earth.2019.170284

Ostracoda assemblages have been studied from Fat'ha Formation (Middle Miocene) at SW limb of Bazian anticline, Sulaymaniyah,Kurdistan region, Iraq.  The Paleoecology of ostracoda assemblages points to shallow marine water that changes to barrier lagoon water setting due to tectonic activity event. The application of statistical analysis (Simpson index) leads to the subdivisions of Fat'ha Formation into five ecozones in the studied area.

Biostratigraphy Study of Planktonic Foraminifera in Shiranish Formation and its Contact with Aaliji Formation in Pulkana Well No. 7 North Iraq

Abdullah Al-Hadidi; Mohamed Ahmed

Iraqi National Journal of Earth Science, 2019, Volume 19, Issue 2, Pages 41-59
DOI: 10.33899/earth.2019.170276

Planktonic Foraminifera is studied from Shiranish &Aaliji formations in PulkanaWell No. 7 North Iraq between the depth intervals (1948-2240) m, six biostratigraphy zones are recognized in the formation as arranged from bottom to top:
1. Globotruncanita stuarti–stuartiformis Partial Range Zone.
2. Globotruncana aegyptiaca Interval Zone.
3. Gansserina gansseri Total Rang Zone.
4. Morozovella angulata  Partial Range Zone.
5. Globanomalina  pseudomenardii  Total Rang Zone .
6. Morozovella velascoensis Partial Range Zone.
The result of this study is compared with the work of others inside and outside Iraq, The age of the Shiranish Formation is Early Late Campanian to Earliest Maastrichtian whereas Aaliji Formation is Late Paleocene.

Calcareous Nannofossils Biostratigraphy of Shiranish Formation (K-306) well, Northern Iraq

Maryam Al-Maamari; Omar Al-Badrani

Iraqi National Journal of Earth Science, 2019, Volume 19, Issue 2, Pages 1-10
DOI: 10.33899/earth.2019.170278

Twenty Samples of Shiranish Formation from the well (K-306), Kirkuk area, northern Iraq, are collected and studied on the basis of stratigraphic ranges of the recorded calcareous nannofossils. Eighty-nine species in the studied section reveals five biozones arranged from oldest to youngest as follows:
1.Quadrum trifidum Interval Biozone (CC22) Part
2.Tranolithus phacelosus Interval Biozone (CC23)
3.Rienhardtites lives Interval Biozone (CC24)
4. Arkhangelskilla cymbiformis Interval Biozone (CC25)
5. Nephrolithus frequens Rang Biozone (CC26) Part
These Biozones are correlated with other calcareous nannofossils biozones, from both local and regional sections, leading to conclude the age of Campanian- Maastrichtian.

Environmental Criteria of Stromatolitic Limestones in The Barsrain Formation from Surface Sections, Northeastren Iraq

Mauj Al-Badrani; Rafee Al-Humaidi

Iraqi National Journal of Earth Science, 2019, Volume 19, Issue 2, Pages 80-99
DOI: 10.33899/earth.2019.170279

The rock successions of Barsarin Formation Late Kimmeridgian was studied at three surface sections the type section "17m", Sarglu "19m" and Rania "10m"; northeastern Iraq. The detailed sedimentological study reveals that the formation consists mainly of dolomite and dolomitic limestones. A wide spectrum of diagenetic – processes are recognized in the rock successions; these are dolomitization, compaction, cementation, micritization, dissolution, replacement, neomorphism and silisification. By the far, dolomitization and compaction are the most common and widespread processes. Stromatolites are the dominant primary sedimentary structures in this Formation. Based on field observation and textural characteristics four stromatolite types are distinguished: planar, wavy, domal, and bedded. They are normally formed by carbonates (lime muds) and extensively suffered early dolomitization

Planktonic Foraminiferal Biostratigraphy of Tanjero Formation (Late Maastrichtian) in Bekhme Area, Northeastern Iraq

Majid Al-Mutwali; Muthana Ibrahim

Iraqi National Journal of Earth Science, 2019, Volume 19, Issue 1, Pages 1-21
DOI: 10.33899/earth.2019.170035

The biostratigraphy of Tanjero Formation has been investigated within a well-
exposed section at the northern limb of Perat anticline, Bekhme area, Northeastern Iraq.
The studied section consists mainly of marl, marly limestone, and sandstone. The
formation conformably overlies Shiranish Formation (Late Campanian-Maastrichtian)
and it is overlain unconformably by the Kolosh Formation (Paleocene). The samples of
the section under investigation yielded rich and well diversified planktonic foraminiferal
taxa, where 69 planktonic species belonging to 21 genera have been recognized. The
detailed foraminiferal investigation permits the recognition of four well defined zones.
These are from older at the base:
4. Plummerita hantkeninoides Total Range Zone.
3. Pseudoguembelina palpebra Partial Range Zone.
2. Pseudoguembelina hariaensis Interval Zone.
1. Racemiguembelina fructicosa Interval Zone.
The Planktonic zones were correlated with other zonal schemes in- and outside
Iraq. They are considered to be of Late Maastrichtian age.

Calcareous Nannofossils Biostratigraphy of the Lower Part of Balambo Formation (Lower Cretaceous) in Azmir Anticline - Northeastern Iraq

Enass Al-Khafaf; Majid Al-Mutwali

Iraqi National Journal of Earth Science, 2019, Volume 19, Issue 1, Pages 19-38
DOI: 10.33899/earth.2019.170269

The present research includes a biostratigraphic study of calcareous nannofossils of the lower part of Balambo Formation (Lower Cretaceous) in Azmir anticline - northeastern Iraq. Lithologically, the lower part of the studied section (Balambo Formation) consists of limestone containing nodules of chert, marly limestone, with intercalations of green and gray-blue shale. In this work, it has been relied on calcareous nannofossils assamblages in biostratigaphy and age determination of this part because it does not contain planktonic foraminifera. First occurrences (FOs) and last occurrences (LOs) of marker species were used to identify biozones. The section was divided into four main biozones and two subzones and its correlation with collection from global, regional, and local biozones. Thus, the age of this part of the formation extends from the Late Early Hauterivian - Late Aptian. These are from older to younger:
1- Speetonia  colligata  Interval  Zone (part)
2- Lithraphidites  bollii  Interval  Zone
3- Micrantholithus  hoschulzii  Partial range  Zone
4- Chiastozygus  litterarius Interval  Zone
     Hayesites  irregularis  Interval  Subzone 
    Eprolithus  floralis Interval  Subzone (part)

The provenance of Eocene sandstones (Gercus Formation), Northern Iraq

Zaid A. Malak; Nabil Al-Banna; Majid Al-Mutwali

Iraqi National Journal of Earth Science, 2019, Volume 19, Issue 1, Pages 57-68
DOI: 10.33899/earth.2019.170267

      Gercus Formation is exposed in northern Iraq. When the passive Arabian continental margin collided with the active continental margin of the Turkish and Iranian plates, a part of the source rocks of Gercus red beds were carried out from Iran and Turkey territories and deposited in the molasses trough, parallel to the suture zone of the collision, and the others were driving from the longitudinal paleo-high lying parallel to the trough basin of Gercus Formation.
     The present study is based on three surface sections, Bekhme, Sarsank and Amadiya areas in Northern Iraq. Generally, the Gercus Formation consists of reddish brown to light grey, well bedded sandstones and mudstones in addition to thin beds of conglomerates. The most of sandstone particles are composed of polycrystalline and monocrystalline quartz (of metamorphic and plutonic origin), K and Na – feldspar (derived from igneous and metamorphic source rocks), and chert grains of sedimentary source. Carbonate and other rock fragments with low ratio of mica group and heavy minerals (magnetite and rutile) are present too.
       The sandstones of Gercus Formation, generally contain low-moderate quantities of clay as matrix in all sections, therefore, they are texturally immature. On the other hand, the low ratio of quatrz and chert to feldspar and other components indicates to mineralogically immature sandstones. According to McBride classification, it is sublith arenite - Lithic arenite sandstone. Petrographic analysis of sandstones in Bekhme section revealed that it consist of variable amount of detritus, represented by the abundance of quartz and chert rock fragments with low content of feldspar, and at Sarsank and Amadiya sections, the Gercus sandstones are characterized by the abundant chert rock fragments with high percentage of metamorphic rock fragments. So they lay in the recycled provenance source of collision orogen.

Calcareous Nannofossils Biostratigraphy of Aaliji Formation in Well (K- 116), Northern Iraq

Raghda Saad Al-Hyaly; Omar Ahmed Al-Badrani

Iraqi National Journal of Earth Science, 2019, Volume 19, Issue 1, Pages 35-45
DOI: 10.33899/earth.2019.170265

Thirteen samples of Aaliji Formation from the well (K-116), Kirkuk area, Northern Iraq, are studied on the basis of the stratigraphic ranges of the recorded calcareous nannofossils for sixty species, the studied section reveals five biozones arranged from oldest to youngest as follows:

Fasciculithus tympaniformis Interval Biozone (CP4)
Heliolithus kleinpellii Interval Biozone (CP5)
Discoaster mohleri Interval Biozone (CP6)
Discoaster nobilis Interval Biozone (CP7)

5. Discoaster multiraditus Interval Biozone (CP8)
These biozones are correlated with other calcareous nannofossils biozones from both local and regional sections leading to conclude the age of Middle Paleocene to Early Eocene.

Planktonic Foraminiferal Biostratigrapy of Shiranish Formation in Makhmur Well No. (1), Makhmur Area, Northern Iraq

Abdullah Al-Hahidi

Iraqi National Journal of Earth Science, 2010, Volume 10, Issue 2, Pages 19-28
DOI: 10.33899/earth.2010.5516

Planktonic foraminifera is studied from Shiranish Formation in Makhmur
well No. (1), North Iraq between the depth interval (657-620) m. Three
biostratigraphy Zones are recognized in these formation:
1. Globotruncanita elevata–Rosita fornicata Zone.
2. Globotruncana aegyptiaca Zone.
3. Gansserina gansseri Zone.
20 عبد الله سلطان شهاب الحدیدی
The results of this study are compared with the work of others inside and
outside Iraq. The age of the Shiranish Formation in the said well is Late
Companian to Early Maastrichtian.

Tectonostratigraphy of Lower Cretaceous in Southern Iraq

Wathiq GH. AL-mutury; Rafed A. AL-Muhammad; Kaise Al-Bayatee

Iraqi National Journal of Earth Science, 2010, Volume 10, Issue 2, Pages 29-44
DOI: 10.33899/earth.2010.5517

Stratigraphic units during Lower Cretaceous in southern of Iraq
were affected largely by tectonic agent. Neo-Tethys ocean
occupied the distance between passive margins of Arabian and
Iranian plates. South of Iraq represented the continental shelf of
passive margin of Arabian plate. This tectonic situation made the
sediments in eastern parts of passive margin in south of Iraq
effected by marine agents, and the sediments in western parts was
effected by continental agents, whereas the middle parts was
effected by both agents. As result of that, three sediment regions
were formed in south of Iraq. First, marine sediment region that
occupy the eastern part of south of Iraq near the Iraq-Iran borders.
Second, mixed sediment region that occupy Basra area and extend
toward north. Third, continental sediment region that occupy
western part of Basra near the western desert. Half graben basins
that formed by listric faults in the passive margin caused the local
changes in distribution of sediments in south of Basra. These three
sediment regions formed all during Lower Cretaceous and maybe
extend toward the middle of Iraq and north of Baghdad

Some Recent Gastropoda From Khor Al-Zubair, Northwestof Arabian Gulf

Ramzi Al-Naser; Mohammed W. Al-Abbasi; Ali H. Elewi

Iraqi National Journal of Earth Science, 2010, Volume 10, Issue 1, Pages 19-30
DOI: 10.33899/earth.2010.5565

ABSTRACT Khor Al-Zubair channel is a shallow arm of the Arabian gulf, it is located between shatt Al-Basrah from the north west and the Arabian gulf at the south east. Six species belonging to six genera and four families were identified in this study. These are; Euchelus (Euchelus) asper, Clypeomorus clypeomorus, Hexaplex (Muricanthus) kusterianus, Murex (Murex) tribulus, Nassarius (Nassarius) arcularius and Thais sp. The presences of there in a sandy and muddy sediments is more likely indicate that their distribution occur between the Sub to the Middle littoral environment of Khor Al-Zubair channel with depth ranging between (1-15m).

Facies Analysis and Depositional Environment of Khurmala Formation in Bekhair Anticline –Dohuk Area, North Iraq

Nabil Al-Banna; Majid M. Al-Mutwali; Jamal S. Al-Ghrear

Iraqi National Journal of Earth Science, 2006, Volume 6, Issue 2, Pages 13-22
DOI: 10.33899/earth.2006.36375

The studied surface section of Khurmala Formation which lies in the northeast of Dohuk city north Iraq consists of mixed carbonate and clastic sediments, package about 60 meter thick of Early Eocene age. The carbonate sediment is comprising four microfacies association allocated to shoal bank (Kh2), lagoon (Kh1), intertidal (Kh1, Kh3), and supratidal (Kh4), while the clastic sediment included two lithofacies affiliated to estuaries depositional environment. A depositional model of the Khurmala Formation was proposed.
Diagenetic processes of dissolution and dolomitization are recognized in microfacies (Kh3).