List of Articles Oligocene-Miocene

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  1 - Foraminiferal Biostratigraphy of Oligocene to Lower Miocene Deposits (Pabdeh, Asmari, Gachsaran formations) in south-west of Qir, Fars
  نوشا  نوروزی  Daneshian  Baghbani  Aghanabati
  Lower Oligocene and Miocene deposits in Zagros include several formations with considerable lithological changes and faunal diversification. To study these formations more accurately and identifying the boundary among them, 414 samples of Halegan well #1 on the southwes More

  Lower Oligocene and Miocene deposits in Zagros include several formations with considerable lithological changes and faunal diversification. To study these formations more accurately and identifying the boundary among them, 414 samples of Halegan well #1 on the southwest of Qir were studied. Lower Oligocene and Miocene deposits of Halegan well #1 with 414 meter thickness; consist of argillaceous limestone, dolomite, and limestone with intercalation of marl and gypsum and formed the Pabdeh, Asmari and Gachsaran formations. The upper parts of Pabadeh Formation at its upper section include planktonic foraminifera with the age of lower Oligocene Foramtion has Rupelian age and covers conformably the lower part with late Eocene age. The upper boundary of the Pabadeh Formation is conformable with the Asmari Formation. Based on Thomas (1948) definition of the Asmari Formation, in the Halegan well, the Asmari Formation consists of the lower (Oligocene) and middle Asmari (Aquitanian). The upper boundary of the Asmari Formation is unconformable with the Gachsaran Formation. Based on paleontological studies of the lower Oligocene-Miocene deposits of Halegan well, 32 genera and 48 species of benthonic foraminifera and 13 genera and 21 species of planktonic foraminifera were identified and five biozones can be correlated with Wynd’s (1965) biozones 55,56,57,59,63. In ascending order they are: 1-small Globigerina spp. assemblage zone (No. 55) 2-Lepidocyclina-Operculina-Ditrupa assemblage zone (No. 56) 3-Nummulites intermedius-Nummulites vascus assemblage zone (No. 57) 4-Austrotrillina asmariensis-Peneroplis evolutus assemblage zone (No. 59) 5-Rotalia-Elphidium assemblage zone (No. 63) Manuscript profile
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  2 - Biostratigraphy and microfacies of the Asmari Formation in north flank of Khami anticline (north of Gachsaran)
  Mona Rahim Abadi Hossein Vaziri-Moghaddam Ali Seyrafian farzad Sotohian
  In the present study, biostratigraphy, microfacies and sedimentary environment of the Asmari Formation in north flank of the Khami anticline in the north of the Gachsaran province is investigated. The Asmari Formation at the study section with a thickness of 276 meters More

  In the present study, biostratigraphy, microfacies and sedimentary environment of the Asmari Formation in north flank of the Khami anticline in the north of the Gachsaran province is investigated. The Asmari Formation at the study section with a thickness of 276 meters is a thin, medium and thick to massive limestone, nodular limestone, marl, marly limestone, dolomite and dolomitic limestone. In this study 166 thin sections are studied and 23 genera and 24 species of foraminifera have been identified and 3 biozones are introduced. 1- Archaias asmaricus-Archaias hensoni-Miogypsinoides complanatus Assemblage zone. (Chattian) 2- Indeterminate zone (Aqutanian) 3- Borelis melo curdica-Borelis melo melo Assemblage zone. (Burdigalian) Thus, the age of the Asmari Formation at the study area is Chattian to Burdigalian (Oligo-Miocene). Based on study of thin sections and by considering the sediment texture, distribution of skeletal and non-skeletal grains, 12 microfacies are recognized which were deposited in open marine, bar, semi-restricted and restricted lagoon. Four platform types for the Asmari Formation at the study area in comparison with the recent studies on Asmari Formation including: 1-Rupelian-lower Chattian: Distally steepend ramp, 2-middle Chattian-upper Chattian: open shelf, 3-Aqiutanian: homoclinal ramp, 4-lower Burdigalian: carbonate platform. Manuscript profile
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  3 - Microfacies and Sequence stratigraphy of the the Qom Formation in Kuh-e Charkheh (Natanz), Western Zefreh and Varton sections, northeastern Isfahan
  Amir Pedramara Mehdi Yazdi Zahra Maleki Ali Bahrami
  In this research, the deposits of the Oligocene-Miocene Qom Formation in Kuh-e Charkheh (Natanz), Western Zefreh and Varton sections, northeastern Isfahan were studied. According to the field observations and thin section analysis in Carbonate part of the mentioned sect More

  In this research, the deposits of the Oligocene-Miocene Qom Formation in Kuh-e Charkheh (Natanz), Western Zefreh and Varton sections, northeastern Isfahan were studied. According to the field observations and thin section analysis in Carbonate part of the mentioned sections, 8 microfacies were identified, which were deposited from shallow part of lagoon to open marine and the sedimentary environment of 3 sections due to absence of reef and presence of bioclastic barrier and absence of spillage, the homoclinal carbonate ramp was detected. According to the sequence stratigraphic studies, each of the studied sections has two 3rd sequences. In Kuh-e Charkheh section, both sequences include of TST and HST, which are separated by sequence boundary SB2. In the western Zefreh section, the first sequence includes of TST and HST that is separated from the second sequence (include of LST, TST and HST) with sequence boundary SB1. In the Varton section, the first sequence is aggredation type and separated from the second sequence, which include TST and HST by a sequence boundary SB2. Manuscript profile