Iraqi Bulletin of Geology and Mining

The present paper deals with the variability of the primary isotopic composition of seawater in the shallow water zone. Sedimentary successions of middle Miocene outcropping in the eastern part of Iraq provide an excellent archive of the oxygen and carbon isotopes. We analyzed the δ13C and δ18O to investigate the relationship between the lithostratigraphic units and the deviation of the stable isotopes. The results show a significant relationship between the depositional energy changes and both δ13C and δ18O composition. That displays the details of oxygen isotope events (Mi-events) and additional information about Mi2 and 3 zones, reflecting significant changes in the glaciation period, which have minor steps (interglacial period). At the same time, carbon isotope maxima (CM-events) reflect changes in organic carbon burial and refine the Monterey Excursion. Facies analysis revealed several microfacies could be distinguished, reflecting depositional environments including; supratidal and intertidal, lagoon, patch-reef, and open marine environments, matching with their isotopes storage differential, enhancing 13C and high rates of sedimentation in deeper facies. The stable isotopes (18O/16O and 13C/12C) provide an excellent archive of the Neogene (middle Miocene Transgression) 's paleoceanography for the Neo-Tethys. Oxygen and carbon isotopic stratigraphy for bulk rock were analyzed to distinguish Monterey Event and climate optima.

The planktic foraminiferal assemblages were recorded from the Cenomanian/ Turonian boundary from the outcrops section in Kosrat anticline (NE of Dokan dam), within the high folded-thrust zone (Sulaimani area, Kurdistan Region, Iraq). They are assigned to the Middle-Late Cenomanian Rotalipora cushmani partial Zone and to the lowermost Turonian Whiteinella archaeocretacea partial range Zone, in addition to the late Turonian age represented by Helvetoglobotruncana helvetica have been recorded across the Cenomanian/ Turonian boundary, where the early cretaceous platform developed into Kurdistan Foreland basin, as result of the initial phase of Arabian plate subduction beneath the Iranian (Eurasian) Plate. The high-resolution foraminiferal biostratigraphic analysis has been undertaken on the Dokan Formation, Gulneri Formation, and lowermost part of the Kometan Formation, almost revealing a minor gap between the latest Cenomanian and Early Turonian, as well as between the Ealy Turonian and the late Turonian age. The termination of Early cretaceous inner ramp (Rudists) carbonate facies associations by the middle to late Cenomanian represents by the uppermost stromatolite beds of the Qamchuqa Formation. They are overlain by rapid drowning, which is characterized by Planktic bathyal facies association with Dokan Formation. The increase in drowning is associated with the deposition of organic-rich black shale of the Gulneri Formation with a remarkable short-term gap between them. The thin black shale, which is sandwiched between the early and late carbonates sequences, almost shows a diagnostic shift in the planktic foraminiferal associations and marks the Cenomanian – Turonian Boundary Event (93.9 Ma). They are also characterized by abnormal carbon cycle perturbations in Earth's history and associated with oxygen deficiency in oceanic waters (Oceanic Anoxic Event 2 = OAE 2), in Kurdistan and northern Iraq.

Biostratigraphy of the Shiranish Formation is investigated in Jambour Well No.61, Kirkuk area, Northeastern Iraq, which is located about 150 Km Southeast of Kirkuk city. The lithology of the Shiranish Formation in the studied well is composed of an alternation of marl, marly limestone, and limestone. The purpose of this paper is to record the planktic foraminiferal species in the studied section and establish the biostratigraphy zones of planktic foraminiferal and correlated them with their equivalent biozones in and outside Iraq in order to determine the age of the studied section. Eighteen species of planktic foraminifera are described in eighteen samples collected from the studded well. Both suggest the Late Campanian to Early Maastrichtian age. Based on the recognized planktic foraminifera, it is subdivided into three biozones these are from base to top: (Globotruncanita elevata – Rosita fornicata biozone, Globotruncana aegyptiaca biozone, and Gansserina gansseri biozone).

A total of eighteen groundwater samples and two spring samples were collected from the Iraqi part of the Lesser Zab River Basin (LZRB) and analyzed for physicochemical parameters major, minor, nutrients ions, and trace elements as Si, Fe, Al, Mn, Li, Sr, Br, Ba, B, Pb, Zn, Cr, V, Cu, Co, Ni, As, Se, Mo, Cd, Sb, and U. The chemical analyses show that the groundwater of the LZRB is alkaline, and the Ca2+, Mg2+, HCO3-, and SO42- are the major contributing ions, and the NO3- is the major nutrient. The major governing factors of groundwater chemistry in the basin are rock weathering, dissolution/precipitation of minerals, and ion exchange. Based on international and Iraqi water quality standards, all groundwater samples are undrinkable for a human being. Whereas, Pb exceeds the standard limit for most samples. Some other water quality parameters are exceeding the prescribed limits for some samples. Based on relevant parameters and classification, all samples are suitable, with certain qualifications, for irrigation and livestock watering.

An environmental geochemistry review was carried out for selected areas of Iraq. This review highlights the importance of the presence of toxic trace elements as indicators of environmental pollution in soil, sediment, water, and air. The most important results of previous studies, 20 years ago, were discussed for the content of toxic trace elements (Cu, Zn, Co, Ni, Pb, Cr, and Cd) for water and sediments soil pollution, and the last 10 years of air pollution for the same elements. This article is concluded that sediments and soils have relatively more contamination with trace elements than water. This is due to the fact that the soils had cumulative pollution over a long time and it was adsorbed on clays and organic materials.
Likewise, trace elements are concentrated with heavy minerals’ chemical formulas. Maximum concentrations in recorded studies of Cr (570 ppm). This was recorded in 2015 in the sediments of Al-Hammar Marsh. Soils of the capital, Baghdad, are contaminated with Zn (133.3 ppm), Co (30.7 ppm), and Pb (153.7) as a result of urban activities and authigenic the presence of clay minerals and organic matter. Iraqi agricultural soils are polluted with a high concentration of Ni and Cu, and this confirmed the highest percentage of Ni (193.4 ppm) in the Al-Mishkhab soils in the Najaf area as well as Cu (51.8 ppm) in Ishaqi farms. The Kirkuk Oil Refinery was a source of soil pollution with Cd with a concentration of (12.6 ppm) concentrations relative to other areas due to combustion products. The review revealed that Al-Hammar Marsh water symbolizes the most dangerous environmental pollution with studied trace elements Cu (38.4 ppm), Zn (233 ppm), Co (4.7 ppm), Ni (37.6), Pb (36 ppm), Cr (31 ppm), Cd (0.7 ppm and As (15 ppm). This is attributed to unsuitable human customs and oil waste in southern Iraq. The Baiji Industrial district has the maximum air pollution among the other industrial activity areas in Iraq. It is very evident in the high concentration of Cd (62.2 µg/m3).

In this work, the Missouri Rock Fall Hazard Rating System (MORFH RS), named as Risk-Consequence rockfall hazard rating system, was used as an attempt to assess the rockfall hazards of the road rock cuts along the “Mirawa” main road, especially, after the population and urban growth witnessed in the area in the last decade. The MORFH RS is a risk-consequences-based classification system that includes 22 factors, including 9 factors for risk, 10 factors for consequence, and 3 adjustment factors.
Seven (7) sites of rock cuts along 2.36 Km of the Mirawa main road have been studied in detail. These road cuts consist of the clastic rocks (sandstone, siltstone, and claystone) of the Injana Formation of the Late Miocene age. The Mirawa main road is located to the north of Shaqlawa summer resort, between Darband village (in the southeast) and Mawaran–Ulia village (in the northwest), within Erbil Governorate, Kurdistan Region, N-Iraq.
The used risk-consequence rockfall rating system diagram shows that; five-rock cuts (S-6, S-10, S-11, S-14, and S-22) have High risk-High consequences, and only two rock cuts (S-18 and S-22) have “Low risk-High consequences”.
The risk-consequence rockfall hazard rating diagram shows that; the rock cuts (S-6, S-10, S-11, S-14, and S-22) are within the “High Hazard Zone” (Zone A), while the rock cuts (S-18 and S-20) are within the “Moderate Hazard Zone” (Zone B). Accordingly, the “Mirawa” main road is high to moderate rockfall hazards for vehicles and road users, and two maps related to the “risk-consequence” rockfall ratings were prepared.