Upper Cretaceous Oceanic Red Beds (CORBs) are pelagic sediment
deposits that deposited in the Upper Cretaceous basin, with widespread in
part of the world as well as in Iraq. This research investigates the deposition
of cyclic marl and marly limestone CORBs of six selected sections at the
active southern margin of the Tethys during the Late Campanian -
Maastrichtian with petrography, microfacies, and depositional environment.
As this study was not a consideration in the past, so decided to visit and
identify all exposure areas of the Upper Cretaceous period rocks are visited.
This study involved two fields touring reconnaissance extended from
Darbandikhan city in the east south to Shiranish Village in the west north.
Six lithological sections covering the studied area, four sections represent
Cretaceous Oceanic Red Beds (CORBs) and two sections without (CORBs)
for the purpose of comparison between them. The sections are described in
detail and 250 samples were collected from all studied sections.
For the petrography and microfacies analysis 149 thin sections were
studied. The microfacies analysis showing two major successions with Red
Bed and Non-Red Bed marl and marly limestone, occasionally interbedded
with thinly beds of shale, sandstone and siltstone. These comprised of five
microfacies are Oligostegina Marly Limestone, Globotruncana Marly
Limestone, Marlstone with Microfossils, Red Marlstone, and Red to
Variegated Calcareous Sandstone with Radiolarian (Debrise Flow) Making
20 thin sections from Gendilly section(GS) (the typical section of this study)
for microscopic study of minute fossils (nannofossils) examination, for this
study proved that the Cretaceous Oceanic Red Beds (CORBs) dating is
Mastrichtian age. The Microfossils and nannofossils tests proved the
presence of Danian Age in studied area.
This study has proved that the carbonate content in red limestone beds
ranged between 53.5-100.0 %, while this percentage ranged in red marly
rocks between 20.5-50.0 %, But in the rocks that do not contain red beds,
Carbonate content in limestone rocks ranged between 52.0-100.0 %, and in
marl rocks this ratio ranged between 27.5-49.5 %.
The Pila Spi Formation (middle – late Eocene) was studied in terms of field character, Petrography and geochemistry from two outcrops (Bakhar and Bani bawy) sections, Northern Iraq. The field studies showing massive, lithified limestone to marly limestone high effected by dolomitization. The petrography studies shows that most of the skeletal grains was destroyed due to digenetic processes specifically the dolomitization, and the vast majority of carbonate rocks are mudstone and few beds of wackestone. The geochemical study reveals low CaO% and high MgO% content due to the intense effect of dolomitization, and the carbonate rocks was classified as impure limestone generally of slightly calcareous dolomite. Ca/Mg and Sr/Ca ratios have b
... Show MoreThe Fort Munro Formation is well exposed along DG Khan-Fort Munro road, a type locality. The section was measured and sampled for the biostratigraphy, where it has a conformable lower contact with Mughalkot Formation and is underlain by the Pab Sandstone. The total observed thickness was 105 meters, and 26 samples were collected from top to the bottom at random intervals. Fifty thin sections were studied carefully, and five species of large benthic foraminifera, including Orbitoidestissoti, Orbitoidesapiculata, Orbitoides media, Orbitoideshottingeri, and Omphalocyclusmacroporus were identified along with miliolids. Gastropods, Bivalves and Echinoderms were also observed. Based on identified microfossils, the de
... Show MoreThe CenomanianÐEarly Turonian reservoirs of the Mishrif Formation of the Mesopotamian Basin hold more than one-third of the proven Iraqi oil reserves. Difficulty in predicting the presence of these mostly rudistic reservoir units is mainly due to the complex paleogeography of the Mishrif depositional basin, which has not been helped by numerous previous studies using differing facies schemes over local areas. Here we present a regional microfacies-based study that incorporates earlier data into a comprehensive facies model. This shows that extensive accumulation of rudist banks usually occurred along an exterior shelf margin of the basin along an axis that runs from Hamrin to Badra a
The use of Right dihedral method, Lisle graph, and Mohr diagram allows the analysis of the paleostress. Fault slip data were measured for eighteen data of two stations located within Chia Gara structure in Dohuk area in the High Folded Zone, Northern Iraq. Depending on Mohr diagram, Bott equation, and vertical thickness, the magnitudes of the paleostress at the time of the tectonic activity were determined. Firstly, Georient Software was used to estimate the orientation of the paleostresses (σ1, σ2 and σ3). Secondly, using the rupture –friction law, taking into account the depth of the overburden, the vertical stress (σv) was calculated to determine the magnitude of the paleostresses in the study area. The values in st
... Show MoreThis research aims to study the structural analysis of the 2D reflection seismic data for the Judaida subsurface structure located in Kirkuk province, northern Iraq. It is located 60 Km southwest of Kirkuk oil field, and 35 Km southwest of Jambur oil field, the Daquq River passes through the study area. The reflectors in the seismic section were picked and identified by using the synthetic seismograms generated from the logs data of the Jd-1 well. Three main seismic reflectors, Fatha, Jeribe, and the Euphrates were chosen. These mentioned sedimentary formations were deposited during the Middle Miocene, Lower Miocene, and Early-Mid Miocene respectively. Time and depth maps were drawn for these three reflectors by processing average data f
... Show MoreThe environmental impact was illustrated by rockslide and erosion on the Duhok Dam and its reservoir. The evaluation of the geotechnical characteristics of the Gercus Formation was conducted. The research plan was divided into three phases, field, laboratory, and office works. The fieldwork included studying all the geological phenomena of the region related to the environmental impact. The laboratory work focused on studying the geotechnical properties of the various rock samples taken from the Gercus Formation. Rocklab program was used to define the geotechnical properties of a rock mass. The results indicated the weak resistance of the Gercus Formation rocks to weathering and erosion processes, as well as their weak resistance to slid
... Show MoreThe Carbonate-clastic succession in this study is represented by the Shuaiba and Nahr Umr Formations deposited during the Albian - Aptian Sequence. The present study includes petrography, microfacies analyses, and studying reservoir characterizations for 5 boreholes within West Qurna oil field in the study area. According to the type of study succession (clastic – Carbonate) there are two types of facies analyses:-Carbonate facies analysis, which showed five major microfacies were recognized in the succession of the Shuaiba Formation, bioclastic mudstones to wackstone, Orbitolina wackestone to packstone, Miliolids wackestone, Peloidal wackestone to packstone and mudstone to wackestone identified as an open shelf toward the deep basin.
... Show MoreThe L. Cretaceous succession is the main reservoir rock in the south of Iraq. Although the upper Jurassic Sargelu Formation is the main source rock in this area; however, the organic-rich interval within the studied succession, is contribute in these huge accumulations of petroleum. The pyrolysis parameters of the succession; Sulaiy, yamama, Zubair, and Nahr Umr formations showed that the main kerogen type is type III and II with moderate to good HI, which they refer to gas and/or oil prone especially in Zubair, Nahr Umr, and Sulaiy formations. The quantity parameters indicate potential source intervals in respect to (TOC). The maturity parameters suggest the threshold and peak of petroleum generation, which Tmax values ranged around 430
... Show MoreIn this research, a geotechnical assessment was conducted for clay of the Gercus Formation to determine its suitability for embankment dams. The selected area is located in the north of Iraq. Six samples were collected from two sites in Dokan (Sulaimaniyah) and Haibat Sultan mountain (Koysinjaq), three samples each. Various geotechnical (physical, mechanical and chemical) tests were conducted based on standard specifications.
The results of the grain size test of clay samples showed their conformity with Zone C curves and their suitability for the construction of embankment dams, according to the Iraqi standard for roads and bridges. The results of the
... Show MoreThis research focused up on the Seismic reflection study of a 268.7 km2 area located in the central of Iraq within the Karbala province (Kifl area). The seismic data were reprocessed by Anadarko Petroleum Corporation and its partners Dome International and Vitol with OEC in 2005, the result of processing works has improved the quality of seismic sections in most of the study area. The study area was interpreted by using 3-D seismic data from the Oil Exploration Company. By studying the seismic sections and applying seismic attributes (instantaneous phase) Faults were picked across 3D seismic volume of the studied reflectors. The study area affected by a major fault and minor normal faults, Two fa
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