Correction to: Fusulinoids from the Carboniferous–Permian transition beds from the Abadeh Region (Sanandaj–Sirjan Zone, Iran) The original version of this article unfortunately contained a mistake. Some labels are missing in the figure 3. The corrected figure is included in the next page.

Biostratigraphy and lithostratigraphy of Tarbur Formation (Upper Cretaceous) in Hossein Abad section, Zagros basin (SW of Iran) Abstract The Tarbur Formation is a Reef carbonate lithostratigraphic unit that outcrops in the Zagros basin. To study biostratigraphy and lithostratigraphy of Tarbur Formation in Zagros basin, Hossein Abad Section was selected. In this section, the Tarbur Formation lies unconformably on the Pre-Campanian radiolarite beds and the Sachun Formation overlies the Tarbur Formation uncorformably. 39 foraminifera species belonging to 27 genera were identified from the Hossein Abad section in the Tarbur Formation. Orbitoides media, Orbitoides cf. concavatus, Orbitoides apiculata, Orbitoides sp., Omphalocyclus macroporus, Omphalocyclus sp., Pseudomphalocyclus blumenthalis, Lepidorbitoides sp., Antalyna korayi, Dicyclina shlumbergeri, Archaecyclus midorietalis and Goupillaudina shirazensis are the most significant foraminifers. Based on faunal assemblages, three biozones were proposed: Archaecyclus midorietalis range zone (late Campanian), Orbitoides—Goupillaudina assemblage Zone (early Maastrichtian and Antalyna korayi range subzone (late Maastrichtian). Foraminiferal assemblage of the Tarbur Formation supports late Campanian to late Maastrichtian age in section of Hossien Abad.

Spherulitic dahllite of Duwi Formation phosphorite Abstract Spherulitic dahllite structure is first once recorded microscopically by the present authors in the phosphorite rocks in Duwi Formation in Qusier–Safaga area, Red Sea. Petrographically the study dahllite in the Duwi Formation are authigenic in origin and deposited as a secondary mineral. It is subjected to the re-crystallization process that is one of diagenetic processes. It is resulting from re-crystallization of amorphous calcium carbonate–phosphate and collophane as well as by the weathering effect. Spherulitic dahllite indicated that the phosphorite rocks of the Duwi Formation seem to be subjected to the chemical weathering. Microscopically, the spherulitic dahllite occurs as colorless to pale brown color. It consists of subhedral to anhedral crystals and characteristic by plumose fibrous texture. The spherulitic dahllite structure in the phosphorite rocks at Duwi Formation—Late Cretaceous in Egypt are comparable to those at Thermopolis Formation (Upper Cretaceous), in Cody; as well as in Ishawooa, Park County, and in Big Horn County, Wyoming, United States.

Relating petrophysical parameters to petrographic interpretations in carbonates of the Chorgali Formation, Potwar Plateau, Pakistan Abstract An integrated approach was deployed to relate the petrographical and petrophysical parameters of the Chorgali Formation to assess its reservoir potential. The petrographical study of the Chorgali Formation, exposed in Khair-e-Murat Range, disclosed that the original texture and composition are affected by diagenetic events (i.e. micritization, dolomitization, microfractures, stylolitization, compaction, dissolution, neomorphism and cementation). Of these, dissolution, dolomitization and microfractures enhanced reservoir quality, while micritization, compaction, neomorphism and cementation reduced reservoir suitability. Micritization occurred in marine phreatic conditions; dolomitization existed in the marine-meteoric mixing environment; dissolution, neomorphism and cementation took place in meteoric conditions. The mechanical and chemical compaction occurred in a burial diagenetic environment. In addition, the relationship among formation resistivity factor (F), compressional wave velocity (Vp) and porosity (ɸ) was also validated for the Eocene Chorgali Formation of Meyal Oil Field, Potwar Plateau, Pakistan. There is an inverse relationship between ɸ and F, Vp, however, the relation between F and Vp is directly proportional. Such inter-relationships assist in determining and interpreting the geological processes based on petrophysical parameters (ɸ, F and Vp). F and Vp may be high due to cementation, compaction, sealed fractures and lack of deformation in carbonates. On the other hand, F and Vp may be low due to dissolution, dolomitization, vacant fractures, lack of compaction and cementation. Similarly, ɸ is enhanced by processes lowering F and Vp and reduced by processes increasing F and Vp. Hence the diagenetic processes enhancing and reducing the porosity influence the electric and elastic properties of the carbonate rocks.

Dynamic variation characteristics of water chemistries and isotopes in a typical karst aquiferous system and their implications for the local karst water cycle, Southwest China Abstract The paper chose a typical karst aquiferous system in southwest China to study karst water cycle process to help the sustainable development and utilization of karst water resources. Different water bodies’ water chemistries and isotopes’ characteristics and their implications are analyzed based on the conceptions of transformations among “precipitation, vadose zone water flow, karst conduit water flow, and surface water flow” and the “recharge, runoff, and drainage”. Hydrological information can be obtained by analyzing water chemistries, δD and δ18O values, deuterium excess values, regression equations, influencing factors of all water bodies and precipitation in rainy season and dry season. Topography, geomorphology, and developed characteristics of karst areas affect circulation process of karst water resource, water chemistries and isotopes along the main conduit having a great fluctuation affected by changes of water dynamic conditions. Ca2+ and HCO3− are the main cation and anion in the karst aquiferous system, concentrations of Cl− and NO3− respond to the influence of human activities significantly, the dilution affection of precipitation recharging groundwater on the concentration of Ca2+ and Mg2+ is biggest, and affection of human activities on water bodies in rainy season is higher than dry season. δD and δ18O values have the increasing trend along the underground river flow path for the water–rock interaction; d values are higher and have more obvious fluctuating status along the main flow path in dry season for the long non-successive residence time. δD, δ18O and d values’ dynamic variation characteristics of cave drip water, epikarst springs, karst conduit water, and surface water in different seasons are mainly affected by recharging sources and evapotranspiration, the hydrological environment and fractionation, the developed location and evaporation, condensation and evaporation, respectively. Dynamic variation characteristics of water chemistries, isotopes, d values and their implications in the karst water cycle can help decision makers to take effective measures to protect and utilize karst water resources.

Reservoir space type and storage capacity of Oligocene lacustrine carbonate in the Yingxi area of western Qaidam Basin, China Abstracts Over the past 2 years, a great progress in petroleum and gas exploration has been made in tight lacustrine carbonate rocks of E 3 2 in the Yingxi area. Many high-yield commercial oil flow wells with more than 1000 tons of oil production per day have been found, but their reservoir space type and storage capacity are the key issues highly concerned and disputed by many explorationists. According to the study on systemic petrology and mineralogy, analysis of physical property, study on capillary pressure curve, analysis of ultra-micro crystal morphology, analysis of micro-area geochemical composition, and other comprehensive analysis, and pore types of the E 3 2 reservoir are mainly intercrystalline pores of dolomite, and a small number of dissolution phenomena have been found. Therefore, large-scale oil and gas reservoirs can be formed. The analysis involves these key results and evidences: (1) under the microscope and scanning electron microscope, many intercrystalline pores are developed in dolomite rocks, presenting a “high-wide platform” phenomenon on the capillary pressure curves to imply “small bore—large quantity”. (2) The electron probe shows that the molecular formula of dolomite is Ca(Mg0.96Fe0.04)(CO3)2. In the penecontemporaneous dolomitization process, intercrystalline pores come from volume shrinkage when Mg2+ ions replace Ca2+ ions, and a small number of Fe2+ ions are involved in this chemical reaction. The 13.36% plane porosity can be formed in ideal conditions. (3) According to the statistical data, intercrystalline pores are enlarged by organic acids in several samples, no evidence is available for leaching dissolution of atmospheric water because of exposure, and many types of feldspar do not dissolve. The reservoir rocks are formed due to a high deposition rate. (4) According to the measured pore sizes and the values based on the chemical theory, the pore size is in the range of 0.4–1.07 μm. These pores can store all oil, gas, and symbiosis substances, which can flow or migrate in the pores because of the pore sizes. The pictures of fluorescence thin sections and the backscattered electron images of SEM show that these micro-pores are full of hydrocarbons, creating the oil and gas accumulation pattern of “containing oil for the whole sag” and “producing oil for each well” in the Yingxi area. Based on the oil and gas accumulation model, the Yingxi area is an integrated oil and gas field with the most potential and industrial value in Qaidam Basin. The research results are crucial to the petroleum and gas exploration of carbonates in a saline lacustrine basin.

Hybrid clustering-estimation for characterization of thin bed heterogeneous reservoirs Abstract Modeling heterogeneous reservoirs is cumbersome as it requires a great effort to determine the variation of properties with respect to direction, while the lack of adequate data makes this a difficult task. Generating static models for heterogeneous reservoirs remains an important challenge in petroleum engineering applications which requires more investigations. Some heterogeneous reservoirs, such as thin bed reservoirs, may be divided into some homogeneous subzones where characterization of these homogeneous sub-reservoirs and their integration can represent the properties of the heterogeneous reservoir. To investigate this concept, in this paper, three exemplar reservoirs (ER) were generated. The heterogeneity in the data is increased from ER1 to ER2 and ER3. In the first step, each reservoir was studied as one single zone, so the results can be compared with the proposed method in this work. Ordinary kriging (OK) and multilayer perceptron neural network (MLP) were used for modeling of these exemplar reservoirs. This study showed that OK cannot model reservoir characteristics, whereas the MLP yielded reasonably acceptable results. In the next step, a hybrid clustering classification-based method was applied to divide the reservoir to homogeneous subzones. Each reservoir was modeled in terms of its homogeneous subzones. The homogeneous subzones were modeled using OK and MLP. The results showed that the developed model was successful in modeling the heterogeneity at a reasonable CPU processing time. Also, it was seen that in case of using the simple modeling techniques, MLP neural network yields more reasonable results, compared with OK.

Dam effect on groundwater characteristics from area under semi-arid climate: case of the Zerrar dam within Essaouira basin (Morocco) Abstract Morocco has 140 large dams with a total capacity of 17 Gm3. The amount of potential fresh water is decreased by sedimentation of clays and/or soil in the dam’s reservoirs. It is estimated at 70 million m3, surface evaporation and water loss by the banks and foundations. In this study, the environmental stable and radioactive isotopes together with geochemical and piezometric data were used to assess the impact of Zerrar dam on groundwater in Essaouira basin (western Morocco). The water facies has been determined and has evolved from Na–Cl type (before the establishment of the dam) to Mg–Cl and Ca–Cl type (after establishment). The dissolution of evaporates and ion exchange reactions are the main processes affecting groundwater composition. Groundwater level has been measured and shows a decline. 2H–18O diagram revealed that the aquifer recharge has assured by precipitation of oceanic origin without evaporation and by infiltration from Ksob Wadi. 3H and 14C content shows that this recharge is generally recent and the age of the waters ranges between modern and 2.3 BP (ka). However, the Zerrar dam indirectly influences the groundwater quality of the study area, because this one decreases the flow of the Ksob Wadi that is the main recharge source of the aquifer during rainfall. In addition, this Wadi flow suffers the effect of climate change, which decreases the flow of the Ksob Wadi (river) that adds to the effect of the dam.

Precipitation of calcium compounds onto rock surfaces in water with cementitious material Abstract In this study, the precipitation of minerals onto rock surfaces was investigated to consider whether sealing of pores and cracks in rock can be accelerated. Cylindrical specimens were prepared and then kept in purified water with powders of high-strength and ultra-low-permeability concrete (HSULPC), which will be used to confine transuranic wastes in Japan. Then, the rock specimens were weighed and the surfaces of rock specimens were inspected under a microscope. It was recognized that precipitation occurred on the surface of the rock specimens. It was also shown that precipitation did not occur on rock specimens kept in water without HSULPC. The weight of all specimens stored in HSULPC increased, and the observed weight change was larger for rocks with higher porosities. It is concluded that precipitation of minerals occurs on the rock surface when the rock is kept in water with HSULPC powders. From the results obtained in this study, it is suggested that the sealing of pores and cracks in rock can be accelerated by the precipitation of calcium compounds using HSULPC. It is concluded that HSULPC is useful for underground radioactive waste disposal.

Lithologic characterization of the phosphorite-bearing Duwi Formation (Campanian), South Esna, West Nile Valley, Egypt Abstract The Lower phosphatic member of the least Upper Cretaceous (Campanian) Duwi Formation, south Esna, at the western side of the Nile Valley is important rock unit for its relatively high enrichment of heavy metals and U content. The petrographic, mineralogical, and geochemical characteristics of the studied formation are determined using Polarizing Microscopy, X-ray diffractometry, and X-ray Fluorescence. Petrographically, the studied phosphatic grains are composed of phosphatic mudclasts and bioclasts embedded in varies matrix. Spherulitic dahllite, black opaque minerals, and framboidal pyrite are scattered in the matrix. Dahllite in the studied samples are authigenic in origin and formed as a secondary mineral by the re-crystallization of the original francolite. Esna Phosphatic rocks (Duwi Formation, Campanian) were deposited under reducing condition and were affected by chemical weathering. Mineralogically, they are composed of five mineral phases. Apatite (flour-apatite) and dahllite are the dominance; as well as, quartz, pyrite, and anhydrate. The studied phosphatic rocks samples are compared with the average of the Upper Continental Crust (UCC) and the Post-Archean Australian Shale. The trace and some rare earth element content: Mo, Cr, Sr, Co, La, and U are more enriched than those in the UCC. The trace elements in the study phosphatic rocks may be associated with each other or with the heavy minerals rather than with apatite. U contents in the study phosphatic rocks are associated with the heavy metals and trace elements during the chemical weathering under oxic conditions. The ratios Mo/Al and the high concentrations of the redox sensitive elements revealed that the studied phosphatic rocks were deposited under anoxic reducing marine environments coupled with hydrothermal solutions.