• Home
  • ریز رخساره
    • List of Articles ریز رخساره

      • Open Access Article

        1 - Microfacies, Sedimentary Environment and Sequence Stratigraphy of the Qom Formation, Deh Namak, Northwest of Garmsar
        Jahanbakhsh Daneshian  Asadi Mehmandosti yousef ramezani
        Deh Namak section is exposed along the most northern point of the Qom Formation, where the Central Iran zone and Alborz zone come together. The study of microfacies, sedimentary environments and sequence stratigraphic features of the Qom Formation in this area can h More
        Deh Namak section is exposed along the most northern point of the Qom Formation, where the Central Iran zone and Alborz zone come together. The study of microfacies, sedimentary environments and sequence stratigraphic features of the Qom Formation in this area can help to understand the situation of the Qom sedimentary basin in the northern part, bordering the Alborz zone. 166 samples of the Qom Formation in Deh Namak section in the northwest of Garmsar are investigated. Microfacies analysis of these sedimentary rocks indicates that according to sedimentary environment they consist of nine microfacies belonging to four facies belts including tidal flat, agoon, shoal/reef sediments and slope of platform. Due to the absence of the gravitational and turbidity sediments and abundance of reef/shoal sediments, a rimmed carbonate shelf depositional environment is suggested in which more sediments were precipitated in shallow water. In this model, deep facies of the basin did not spread and the deepest facies belong to the slope. Also, sequence stratigraphic studies show that the Deh Namak section is composed of four sedimentary sequences of third- order, two types II and one type I sequence boundaries were recognized in this formation. Manuscript profile
      • Open Access Article

        2 - Microfacies and sedimentary environment of the Maastrichtian deposits in Jorbat Stratigraphic section, west of Kopet Dagh
        Yadolah Ezampanah Mahmoud Jalali محمد حسين  آدابي امیرمحمد  جمالي
        To determine microfacies and depositional subenvironments of the Maastrichtian deposits in the western part of the Kopet-Dagh Basin, one stratigraphic section, has been selected and analysed. In this section which is located 9.5 kms N-NW of Jorbat, Maastrichtian deposit More
        To determine microfacies and depositional subenvironments of the Maastrichtian deposits in the western part of the Kopet-Dagh Basin, one stratigraphic section, has been selected and analysed. In this section which is located 9.5 kms N-NW of Jorbat, Maastrichtian deposits are composed of two formations including Kalat (282 m thickness) and Chakhmaghlo (77 m thickness). The Kalat Formation consists of bioclastic and sandy limestone and the Chakhmaghlo Formation is composed of shale, marl, limestone and argillaceous limestone. Based on field observations and also petrographic studies, the lower boundary of the Kalat Formation with the Abderaz Formation is disconformable. The lower boundary of the Chakhmaghlo Formation with the Kalat Formation is gradual and conformable, while its upper contact with the Paleocene Pesteligh Formation is disconformable. Petrographic studies in Maastrichtian deposits led to recognition of 16 microfacies. These microfacies deposited in 5 facies belts including tidal flat, lagoon, shoal, reef and fore reef subenvironments in a carbonate platform. Manuscript profile
      • Open Access Article

        3 - Oligocene microfacies and sedimentary environment of the Asmari Formation at northwest of Deris village, west of Fars province: correlation with three other sections in Zagros Basin
        samir Akhzari Ali Seyrafian
        In this disquisition, Oligocene (Rupelian-Chattian) microfacies and sedimentary environment of the Asmari Formation at the northwest of Deris village, located in interior Fars zone of the Zagros Basin have been interpreted. The coordinates of such section are N: 29o 4 More
        In this disquisition, Oligocene (Rupelian-Chattian) microfacies and sedimentary environment of the Asmari Formation at the northwest of Deris village, located in interior Fars zone of the Zagros Basin have been interpreted. The coordinates of such section are N: 29o 41' 59'', E: 51 o 32' 26''. The Asmari Formation deposits in this section are divided into 5 lithological units and consist of 460 m thin, medium, thick and massive bedded, gray and cream to gray limestone, slightly dolomitic with nodular and marly interbedded. By study of hyaline benthic foraminifera genera and non-foraminifera, and also recognition of some properties such as skeletal ingredient associations and sedimentary textures of thin sections, 14 microfacies have been introduced for the Asmari Formation. Gradual perpendicular changes of these microfacies represent that settling the Asmari Formation deposits took place in a homoclinal rapm. This homoclinal ramp consists of middle ramp and inner ramp, that are separated by shoal environment. Middle ramp is recognized by presence and dominition hyaline benthic foraminifera, coralline red algae and echinoids. The most significant skeletal debris of inner ramp are porcelainous foraminifera. To compare the thickness, age and sedimentary environment, zonal correlation of the Asmari Formation done in Deris section with three other sections (Naura anticline, Dill anticline and Dehloran) in the Zagros Basin. This correlation represent that the age of the Asmari Formation gets younger to the deeper parts of the foreland basin of the Zagros. Manuscript profile
      • Open Access Article

        4 - Biostratigraphy and sedimentary environment of Asmari Formation in Davan section, North of Kazerun
        masood khoshnood Hosyen Vaziri moghadam
        This research concentrates on biostratigraphy, microfasies and Sedimentary environment of the Asmari Formation at Davan village in 10 Km north of Kazerun. Micropalaeontological study led to recognition of 25 genera and 15 species of foraminifera. Based on biostratigraph More
        This research concentrates on biostratigraphy, microfasies and Sedimentary environment of the Asmari Formation at Davan village in 10 Km north of Kazerun. Micropalaeontological study led to recognition of 25 genera and 15 species of foraminifera. Based on biostratigraphic study 3 biozones (1-Nummulites vascus – Nummulites fichteli assemblage zone, 2 -Lepdocyclina-Operculina- Ditrupa Assemblage Zone, 3- Archaias asmaricus- Archaias hensoni- Miogypsinoides complanatus Assemblage Zone) are determined. As a result, the age of the Asmari Formation is Oligocene (Rupelian – Chattian) at the study area. Depositional texture, petrographic analyses and fauna led to identification of 9 carbonate microfacies related to open marine, slope, bar and lagoon. These depositional environments correspond to inner, middle, and outer ramp. Manuscript profile
      • Open Access Article

        5 - (Biostratigraphy and microfacies of the Asmari Formation in south flank of Mish anticline (northeast of Gachsaran
        Saber Ahmadi Ali seyrafian Hosyen vaziri-Moghadam
        Asmari Formation at the section of the south flank of Mish anticline (northeast of Gachsaran), located 22 km northeast of Basht city, in vicinity village Kalagh ¬Neshin is investigated and has a thickness of 281 meters. In this research, biostratigraphy and microfacies More
        Asmari Formation at the section of the south flank of Mish anticline (northeast of Gachsaran), located 22 km northeast of Basht city, in vicinity village Kalagh ¬Neshin is investigated and has a thickness of 281 meters. In this research, biostratigraphy and microfacies of the Asmari Formation in this section were studied and the results were compared with 5 section of Asmari Formation in similar regions and close to it. By studying on 172 microscopic sections, 3 the biozone for Asmari Formation in the section the study was carried out and the section studied given that is: Lepidocyclina – Operculina – Ditrupa assemblage zone. Archaias asmaricus – Archaias hensoni – Miogypsinoides complanatus assemblage zone. Indeterminate zone. According to the study of benthic foraminifera and biozones, the cut off age is from the late Oligocene (Rupelian-Chattian) to the early Miocene (Aquitanian). Microfacies studies led to identify 10 microfacies and 4 subfacial belonging to the open marine and lagoon (semi-closed and enclosed) environments, which includes the external, intermediate, and interior parts of a hemocalinal ramp. Manuscript profile
      • Open Access Article

        6 - Qom Formation, Microfacies, Depositional sequence, Maragh area.
        Amrolah Safari Hossein Ghanbarloo Ebrahim  Mohammadi
        The Qom Formation is located at the Maragh area (20 kilometers southwest of Kashan). The formation with 216 m thickness contains shale and limestones. Volcanic rocks unconformably are covered by the Qom Formation. The upper boundary of the Qom Formation with the Upper R More
        The Qom Formation is located at the Maragh area (20 kilometers southwest of Kashan). The formation with 216 m thickness contains shale and limestones. Volcanic rocks unconformably are covered by the Qom Formation. The upper boundary of the Qom Formation with the Upper Red Formation is also unconformable. Nine microfacies and terrigenous facies were identified based on the main components and sedimentological features. These microfacies and terrigenous facies were deposited on an open-shelf carbonate platform. Three environments were recognized in this carbonate platform. These environments include the inner shelf (restricted and semi-restricted lagoon), middle shelf, and outer shelf. In addition, three third-order and one incomplete depositional sequences were identified based on the vertical distribution of microfacies. Manuscript profile
      • Open Access Article

        7 - Reservoir quality evaluation of the Asmari Formation in the framework of sequence stratigraphy in one of the Iranian SW oilfield
        Ebrahim Sfidari A. Hakymi-Zanuz
        The Oligo-Miocene Asmari Formation forms the main reservoir rock of many Dezful Embayment fields. Microfacies analysis, diagenetic features, and sequence stratigraphic evaluation of the Asmari Formation were carried out based on the petrographic investigation, petrophys More
        The Oligo-Miocene Asmari Formation forms the main reservoir rock of many Dezful Embayment fields. Microfacies analysis, diagenetic features, and sequence stratigraphic evaluation of the Asmari Formation were carried out based on the petrographic investigation, petrophysical logs, and core measurement porosity and permeability data. Petrographic analyses led to the identification of twelve microfacies indicating five subenvironments including tidal flat, lagoon, barrier (belonging to inner ramp), middle ramp, and outer ramp, all of which are representing a homoclinal ramp. Tidal flat, lagoonal, and barrier microfacies are mostly present in the upper parts of the Asmari Formation, while middle and outer ramp microfacies were largely developed in the middle part. Cementation, compaction, dolomitization, dissolution, and fracturing are the main diagenetic processes in this formation. Compaction and cementation have negatively affected reservoir quality while fracturing, dolomitization, and dissolution contributed to reservoir quality enhancement. The sequence stratigraphic studies represent three 3rd order sequences of early Aquitanian, late Aquitanian, and early Burdigalian age based on the main features of microfaces, their depositional environments, and shallowing and deepening-upward trends. Microfacies of the Transgressive System Tract (TST) have been affected by compaction, dissolution (moldic), cementation, and slightly dolomitization in the middle to outer ramp parts. The Highstand System Tract in the inner ramp part has been affected by dolomitization, dissolution, and fracturing close to the sequence boundaries, and has a better reservoir quality than the Transgressive System Tract. Manuscript profile