Search

The main lithological composition of different formations in the Iraqi Kurdistan Region is the carbonate rocks; some of those rocks are suitable for cement production; such as Qamchuqa Bekhme, Sinjar, Pila Spi and Anah formations. However, the six existing cement plants in are using limestone beds, five of those plants are using limestone from the Sinjar Formation, and one plant is using limestone from the Anah Formation. Recently, performed research works confirmed that the limestone beds within the Qamchuqa, Bekhme and Pila Spi formations are very suitable for cement production. The current research work deals with studying the exposed limestone beds within the Bekhme Formation at Hareer Mountain in the central part of IKR to check their suitability for the cement industry. Accordingly, we collected 12 rock samples from a section within the Bekhme Formation at an almost constant sampling interval (5 m); however, for two samples the sampling interval was 6 and 8 m (sample No. 2 and 12, respectively). Each sample represents a channel sample for the concerned sampling interval to be representative for the thickness of the sampled interval. The total thickness of the sampled section is 64 m with a covered interval of 30 m, totaling up to 94 m. The collected 12 samples were prepared at the laboratory of the University of Kurdistan Hewler and were subjected to XRF test at Mass Cement Plant (Sulaimaniyah) to check the concentration of certain oxides that are used in the Iraqi Standard for cement production. The acquired concentrations of the main oxides (CaO, MgO, Al2O3, Fe2O3, Na2O, K2O, SO3), and Cl and L.O.I. at each sample were changed to weighted averages and the results were compared with the Iraqi standards for cement industry. The result was the sampled rocks are excellent for cement production.

The Pirmam and Bana Bawi anticlines are two elongated anticlines located in the central northern part of the Kurdistan Region of north Iraq (KRI), in the northeastern part of the Arabian Plate. We have used satellite images and geological maps to interpret the presented data and to calculate the rates of uplift and down wards (subsidence) amounts, besides estimating the rates of deposition and incision of some alluvial fans and stream terraces. Most of the achieved data were checked in the field. In the Pirmam anticline the rate of the uplift and subsidence is 8.613 mm/ 100 year and 7.962 mm/ 100 year, respectively, whereas in the Bana Bawi anticline the rates are 3.036 mm/ 100 year and 4.365 mm/100 year, respectively. The indications of the lateral growth are the presence of water gaps, wind gaps, en-echelon plunging, whale-back shape and different types of valleys. We have calculated the depositional and incision rates in the Kori and Bastoora streams. They are 5.204 mm/ 100 year and 5.555 mm/ 100 year, respectively in the former, whereas in the latter are 3.469 mm/100 year and 8.731 mm/ 100 year, respectively. Moreover, we have calculated the depositional and incision rates in old and recent alluvial fans. In the former, they are 1.665 mm/ 100 year and 0.722 mm/ 100 year, respectively, whereas in the latter are 3.036 and 4.365 mm/ 100 years, respectively. Godkänd;2023;Nivå 0;2023-03-30 (hanlid)

Handreen, Zozik and Tanoun are three major anticlines in the northern part of Iraqi Kurdistan Region located NE of Rawandouz town. All anticlines are oriented NW-SE with a steep southwestern limb. The length and width of Handreen, Zozik and Tanoun anticlines are 20.2 km, 23 km, 27 km, and 10 km, 4.7 km and 2.5 km, respectively. The anticlines are separated by very narrow synclines. However, Tanoun anticline is thrusted over Zozik anticline causing the disappearance of the synclinal axis between the two folds. The oldest exposed rocks in Handreen anticline are the Cretaceous age, in Zozik anticline are the Upper Jurassic rocks, whereas in Tanoun anticline, the Lower Jurassic rocks are exposed. The carapace of Handreen and Zozik anticlines is built up by Bekhme and Qamchuqa formations and that of Tanoun anticline by the Qamchuqa Formation. Satellite images and geological maps were used to recognize the geomorphological and structural features which were checked and confirmed in the field. Handreen, Zozik and Tanoun anticlines show clear geomorphological and structural features which indicate their lateral growth. Among those features are water gaps, wind gaps, forked-shaped valleys, curved valleys, inclined (curved) valleys, radial valleys, abandoned alluvial fans, wale-back shape, en-echelon folds and folds with malty domes.

Aqra Anticline is a double plunging anticline, oriented NW–SE with a steep southwestern limb and even overturned. Geomorphological features are interpreted using satellite images, as a result, it was found that the anticline shows clear geomorphological and structural features which indicate the lateral growth of the anticline. Among those features are water gaps, wind gaps, forked-shaped valleys, curved valleys, inclined valleys and dislocated and abandoned alluvial fans. Some of the vague interpreted features were checked and confirmed in the field.

Korek Mountain is one of the outstanding mountains in the Iraqi Kurdistan Region; located north of Erbil city. It faces the entrance of the famous Galley Ali Beg gorge with its beautiful waterfall. The exposed rocks at the entrance of the gorge belong to the Bekhme Formation which consists of many types of carbonate rocks with a total thickness of around 100 m. The current study is concerned with the industrial assessment of the exposed carbonate rocks in the Bekhme Formation and to indicate the most relevant industrial uses of the exposed rocks. To perform the industrial assessment, samples were collected from the exposed rocks. The first sample was collected from the bottom of the Bekhme Formation within the Korek anticline and the last one was collected from the top of the formation; at systematic intervals. The collected samples were dried, crushed and ground to powder and were subjected to a XRF test. Upon receiving the chemical composition of the analyzed rocks, it was found that the rocks are very suitable for cement production and could be used in other industries such as paper, paint and sugar with little modification. Accordingly, the weighted averages were calculated to estimate the geological reserve in the studied site.

Khabbaz oilfield has a symmetrical subsurface anticline with a length of 20 km and a width of 4 km. Despite the fact that Khabbaz oilfield has a small size structure, it is known as one of the massive Oilfields in Iraq. The reservoirs of Khabbaz oilfield are produced by both Cretaceous and Tertiary rocks. The Upper Qamchuqa reservoir is the most productive reservoir of the Khabbaz oilfield with thickness ranges between 138 to 170 m. This formation is subdivided into two units, from the top is Unit A with a thickness of 67 m and from the bottom is Unit B with a thickness of 84.5 m. From a full set of log data of three wells (Kz-1, Kz-13 and Kz-14), the petrophysical properties of Khabbaz oilfield has been evaluated. The wireline log data includes gamma-ray log, sonic log, neutron log, density log and resistivity logs, both Rxo and Rt logs. This study revealed that Unit A represents the best reservoir characteristics where Unit A is subdivided into six reservoir subunits named (1-A, 2-A, 3-A, 4-A, 5-A and 6-A). They are separated by five non-reservoir subunits named 1-N, 2-N, 3-N, 4-N and 5-N. In addition to a less porous reservoir unit that is called Unit B, which has been divided into four reservoir subunits named 1-B, 2-B, 3-B and 4-B. These are separated by five non-reservoir units named 1-N, 2-N, 3-N, 4-N and 5-N. It has been recognized that both reservoir units A and B are clean formations and have minimum shale volume with high porosity in limestone and dolomite to dolomitic limestone lithology with high oil saturation and low water saturation. Based on the above reservoir characteristics it can be concluded that the reservoir units of the Khabbaz oilfield contain a massive commercial hydrocarbon accumulation.

Microporosity is common in many Middle Eastern carbonate reservoirs and various interpretations have been offered to explain its development, especially in Cretaceous reservoirs. In this study outcrops of late Paleogene carbonates of the north-eastern Iraq have been studied to assess the variation of porosity across a carbonate ramp and the factors that control its distribution. The depositional system of this late Paleogene succession was a homoclinal ramp dipping SW. Inner-mid ramp carbonate facies are massive to thick bedded units, mostly composed of packstone to grainstone, characterized by high diversity of benthic foraminifers, red algae, corals, gastropods and bivalves. Outer ramp carbonate facies are thin bedded wackestone to calcimudstone. In terms of matrix-dominated facies two distinct rock fabrics and pore systems have been identified: low porosity inner-mid ramp facies and higher porosity outer ramp facies. The inner-mid ramp carbonates show evidence of neomorphism and recrystallization of matrix mud which forms larger crystal size (average 3–4 μm) with smaller pore size (0.5 μm or less) and average porosity (8.7%). The outer ramp mud matrices exhibit the major component of planktic foraminifera and coccolith debris have smaller crystal size (average 1 μm) with larger pore size (1–2 μm), the average porosity (13.1%). For the inner-mid ramp matrices carbon and oxygen (C & O) stable isotopic values are negative indicating likely meteoric diagenesis. The relatively low strontium (Sr) and magnesium (Mg) values and high manganese (Mn) implies likely recrystallization and replacement of the marine precursor, probably high Mg-calcite and aragonite. In the outer ramp facies, the presence of coccolith and planktic foraminiferal debris indicates less diagenetic modification; the C & O stable isotopic values show less altered range with very low Mn and relatively high Sr and Mg also supporting less alteration. The textural and geochemical evidence supports an origin from a more stable, likely low Mg-calcite precursor.

The Qamchuqa Formation is well-exposed in the High Folded Zone (HFZ) of northeast Iraq. The formation is highly dolomitized and contains thick reservoir units in the subsurface region south of the HFZ. Deposition of the formation took place at the shelf margin of Early Cretaceous Neo-Tethys Ocean. It merges south- and southeastward to the shallow marine shelf of Arabia and to deep basin accumulations farther north. In the study area, the formation is divided into three members: lower member (250m thick) of interbedded bioclastic calcimudstone/wackestone (MW), bioclastic packstone (BP), bioclastic floatstone (BF) and medium-to coarse-crystalline dolorudstone/dolograinstone (CD). These strata accumulated in low to medium energy, subtidal, fore-shoal setting. The middle member consists of thick succession (325m) of massively bedded CD lithofacies interpreted as high energy shoal facies which represents Barremian-Aptian main shelf-margin succession. The upper member (155m thick) consists of three lithofacies of MW, CD and fine crystalline dolomudstone (FD), in ascending order. It is interpreted as lagoon (MW) through subtidal carbonate sand shoal (CD) to supratidal (penecontemporaneous) dolomudstone (FD). The lower two members represent a long-term Barremian to Aptian shallowing-upward megacycle capped by late Aptian unconformity incurred by relative sea level drop. This temporal gap is coeval with an erosional vacuity recognized throughout the Arabian Peninsula. Sea level rise in early Albian heralded deposition of the upper member which also represents a shallowing-upward cycle surmounted by regionally extensive subaerial unconformity recognized in the Arabian Peninsula. Correlation and stratigraphic position of the formation under regional context has been discussed.

The Late Eocene-Oligocene-Early Miocene sequences of the Kurdistan foreland basin, considered as an important shallow, thick oil and gas reservoir in Kurdistan region/N-Iraq. Several diverse larger foraminifera (Alveolina, Orbitolites, Assilina, Archaias, Austrotrillina, Miogypsinoide, Nummulites, Operculina, Borelies, and Lepdicyclina) with important stratigraphic, paleo-ecological, and palaeo-biogeographical implications are described with respect to its position in the Neo-Tethys basin. The biozonation, using large benthonic foraminifera, leads to the reconstruction of the chronostratigraphic framework. For that purpose, more than 367 samples from six wells and twelve outcrops, from different tectonic domains, within Zagros fold-thrust belt were analyzed. Almost four sequence boundaries (SB) segmented the depositional sequences into three third-order sequences. The lower most sequence boundary was estimated to be of Bartonian age (37 Ma) that represents by more than 5-m conglomerates between the molasses facies of the Gercus and carbonates of the Pila Spi Formations. The second sequence boundary, known as Zagros Major Hiatus, was estimated to be of the age 34 Ma and was placed at the top of karstfied carbonates of the Pila Spi Formation (Pribonian), directly below the Fatha Formation (Burdigalian-Langhian) almost manifesting the boundary between Tectonomegasequence AP10 and AP11. The third one is almost between the Rupelian and the Chattian (28 Ma) within Kirkuk Group. The last recorded one of Aquitanian age (21 Ma) was placed between the Kirkuk Group and Jeribe or Euphrates Formations. The three third-order depositional sequences were recognized from deepening and shallowing trends in the depositional facies, stacking patterns, and sequence boundary features. The first third-order represents the Late Eocene sequence (Pila Spi-shelf facies latterly change to Avanah-Jaddala Formations-depocenter facies), the second one represents the Rupelian-Chattian-Early Aquitanian third order in which each of the lower cycle of the Kirkuk Group (Rupelian) and the upper sequence of the Kirkuk Group (Chattian-Early Aquitanian) represents a fourth-order sequence. The last third order manifests by the Late Aquitanian-Early Burdigalian sequence of the Euphrates shelf facies that is changed laterally to Serikagni depocenter facies and mostly change upwards to Jeribe Formation. The lateral and vertical facial changes point to the increasing of the sequence thicknesses from the high folded thrust zone towards the low folded thrust zone and across the transversal Khanqain fault. The carbonate depositional ramp mostly segmented into isolated highs (occasionally separated from the palaeo-shorelines), that are either due to the influence of the thrust propagation deformational front or reactivation of the deep cited faults.