زيست چينهنگاري و ريزرخسارههاي سازند آسماري در حوضه زاگرس: تطابق زماني و 38 محيطي

Biostratigraphy and Microfacies of the Asmari Formation

در اﻳﻦ ﺗﺤﻘﻴﻖ زﻳﺴﺖ ﭼﻴﻨﻪﻧﮕﺎري، رﻳﺰرﺧﺴﺎرهﻫﺎ و ﻣﺤﻴﻂ دﻳﺮﻳﻨﻪ ﺳﺎزﻧﺪ آﺳﻤﺎري در ﻧﻮاﺣﻲ ﻓﺎرس (ﺗﻨﮓ اﺑﻮاﻟﺤﻴﺎت، ﺗﺎﻗﺪﻳﺲ ﻧﺎاورا، ﺟﻨﻮب ﻏﺮب ﻓﻴﺮوز آﺑﺎد، ﺗﺎﻗﺪﻳﺲ ﺧﻮرﻣﻮج)، زاﮔﺮس ﻣﺮﺗﻔﻊ (ﺗﺎﻗﺪﻳﺲ ﺷﻮروم)، زون اﻳﺬه (ﺗﺎﻗﺪﻳﺲ ﻣﺨﺘﺎر)، ﻓﺮواﻓﺘﺎدﮔﻲ دزﻓﻮل (ﺗﻨﮓ اﻧﺒﺎر ﺳﻔﻴﺪ، ﺗﺎﻗﺪﻳﺲ دﻳﻞ، ﺗﺎﻗﺪﻳﺲ ﺧﻮﻳﺰ، ﻣﻴﺪان ﻧﻔﺘﻲ آﻏﺎﺟﺎري (ﭼﺎه 30)) و ﻧﺎﺣﻴﻪ ﻟﺮﺳﺘﺎن (ﻣﻌﻤﻮﻻن، ﺳﭙﻴﺪدﺷﺖ، دﻫﻠﺮان و ﻛﺒﻴﺮﻛﻮه - دره ﺷﻬﺮ) ﻣﻮرد ﺑﺮرﺳﻲ ﻣﺠﺪد و ﺑﻌﻀﺎً ﺑﺎزﻧﮕﺮي ﻛﺎﻣﻞ ﻗﺮار ﮔﺮﻓﺘﻪ ﺗﺎ ﺷﻤﺎي ﺟﺎﻣﻊﺗﺮي از ﺳﻦ و ﻣﺤﻴﻂ رﺳﻮﺑﮕﺬاري اﻳﻦ ﺳﺎزﻧﺪ ﺑﻪ دﺳﺖ آﻳﺪ. Globigerina spp.-Turborotalia cerroazulensis-Hantkenina, Nummulites vascus-Nummulites زﻳﺴﺘﻲ زونﻫﺎي fichteli (روﭘﻠﻴﻦ) در ﻧﺎﺣﻴﻪ ﻓﺎرس ﮔﺴﺘﺮش دارد. رﻳﺰرﺧﺴﺎرهﻫﺎي ﺳﺎزﻧﺪ آﺳﻤﺎري در اﻳﻦ زﻣﺎن ﻋﻤﺪﺗﺎً ﺷﺎﻣﻞ ﺑﻴﻮﻛﻼﺳﺖ ﭘﻼﻧﻜﺘﻮﻧﻴﻚ، ﻧﻮﻣﻮﻟﻴﺘﻴﺪه، ﻟﭙﻴﺪوﺳﻴﻜﻠﻴﻨﻴﺪه، وﻛﺴﺘﻮن - ﭘﻜﺴﺘﻮن ﺑﻮده و ﺣﺎﻛﻲ از رﺳﻮﺑﮕﺬاري در رﻣﭗ ﺧﺎرﺟﻲ و ﻣﻴﺎﻧﻲ ﻣﻲﺑﺎﺷﺪ. زون زﻳﺴﺘﻲ Archaias asmaricus-Archaias hensoni-Miogypsinoides complanatus (ﺷﺎﺗﻴﻦ) در ﻧﻮاﺣﻲ ﻓﺎرس، زاﮔﺮس ﻣﺮﺗﻔﻊ، اﻳﺬه و ﻓﺮواﻓﺘﺎدﮔﻲ دزﻓﻮل دﻳﺪه ﻣﻲ ﺷﻮد. رﻳﺰرﺧﺴﺎرهﻫﺎي ﺳﺎزﻧﺪ آﺳﻤﺎري در اﻳﻦ زﻣﺎن ﺑﻪ ﻃﻮر ﻋﻤﺪه ﺷﺎﻣﻞ ﺑﻴﻮﻛﻼﺳﺖ ﭘﺮﻓﻮرﻳﺖ - اﻳﻢ ﭘﺮﻓﻮرﻳﺖ ﻓﺮاﻣﻴﻨﻴﻔﺮا وﻛﺴﺘﻮن - ﭘﻜﺴﺘﻮن و ﻣﺎدﺳﺘﻮن ﺑﻮده و ﺣﺎﻛﻲ از رﺳﻮﺑﮕﺬاري در رﻣﭗ داﺧﻠﻲ ا ﺳﺖ. زون زﻳﺴﺘﻲ Miogypsina-Elphidium sp. 14-Peneroplis farsensis(آﻛﻲ ﺗﺎﻧﻴﻦ) در ﻧﻮاﺣﻲ زاﮔﺮس ﻣﺮﺗﻔﻊ، اﻳﺬه، ﻓﺮواﻓﺘﺎدﮔﻲ دزﻓﻮل و ﺑﺨﺸﻲ از ﻓﺎرس و ﻟﺮﺳﺘﺎن ﮔﺴﺘﺮش دارد. رﻳﺰرﺧﺴﺎرهﻫﺎي ﺳﺎزﻧﺪ آﺳﻤﺎري در اﻳﻦ زﻣﺎن ﺑﻪ ﻃﻮر ﻋﻤﺪه ﺷﺎﻣﻞ ﺑﻴﻮﻛﻼﺳﺖ ﭘﺮﻓﻮرﻳﺖ - اﻳﻢ ﭘﺮﻓﻮرﻳﺖ ﻓﺮاﻣﻴﻨﻴﻔﺮا وﻛﺴﺘﻮن - ﭘﻜﺴﺘﻮن - ﮔﺮﻳﻨﺴﺘﻮن و ﻣﺎدﺳﺘﻮن ﺑﻮده و ﺣﺎﻛﻲ از رﺳﻮﺑﮕﺬاري در رﻣﭗ داﺧﻠﻲ ﻣﻲﺑﺎﺷﺪ. زون زﻳﺴﺘﻲ Borelis melo curdica-Borelis melo melo(ﺑﻮردﻳﮕﺎﻟﻴﻦ) در ﻫﻤﻪ ﻧﻮاﺣﻲ ﺣﻀﻮر داﺷﺘﻪ وﻟﻲ در ﻧﺎﺣﻴﻪ ﻓﺎرس ﺑﻪ ﻧﺪرت دﻳﺪه ﻣﻲﺷﻮد. رﻳﺰرﺧﺴﺎرهﻫﺎ و ﻣﺤﻴﻂ رﺳﻮﺑﻲ ﺳﺎزﻧﺪ آﺳﻤﺎري ﻫﻤﺎﻧﻨﺪ زﻣﺎن آﻛﻲﺗﺎﻧﻴﻦ ﻣﻲﺑﺎﺷﺪ. در ﺑﺮشﻫﺎي ﺗﻨﮓ اﻧﺒﺎر ﺳﻔﻴﺪ در ﻓﺮواﻓﺘﺎدﮔﻲ دزﻓﻮل و ﺳﭙﻴﺪدﺷﺖ در ﻟﺮﺳﺘﺎن ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﺣﻀﻮر زون زﻳﺴﺘﻲ .Globigerina spp و رﻳﺰ رﺧﺴﺎره ﭘﻼﻧﻜﺘﻮﻧﻴﻚ ﻓﺮاﻣﻴﻨﻴﻔﺮا وﻛﺴﺘﻮن - ﭘﻜﺴﺘﻮن ﮔﺴﺘﺮش رﻣﭗ ﺧﺎرﺟﻲ را ﻧﻴﺰ در زﻣﺎن ﺑﻮردﻳﮕﺎﻟﻴﻦ در ﻧﻮاﺣﻲ ﻣﺬﻛﻮر ﻧﺸﺎن ﻣﻲدﻫﺪ

In this research, biostratigraphy, microfacies and paleoenvironment of the Asmari Formation in the Fars province (Tang-e Abolhayat, Naura anticline, south-west of Firozabad, Khormuj anticline), High Zagros (Shoorom anticline), Izeh zone (Mokhtar anticline), DezfulEmbayment (Tang-e Anbar Sepid, Dill anticline, Khaviz anticline, Aghajari oil field) and Lurestan province (Mamulan, Sepid-Dasht, Dehluran and Kabirkuh-Darreshahr), werereviewed and revised for the comprehensive understanding of age and depositional environmentsThe Globigerina spp.-Turborotaliacerroazulensis-Hantkenina and NummulitesvascusNummulitesfichteli assemblage zones (Rupelian) are present in Fars province. The dominated microfacies within the Asmari Formation of the Rupelian time are bioclast planktonic, nummulitidaelepidocyclinidaewackestone-packstone, of an outer and middle ramp depositional setting. The Archaiasasmaricus-Archaiashensoni-Miogypsinoidescomplanatus assemblage zone (Chattian) is present in Fars, High Zagros, Izeh and Dezful Embayment provincesThedominated microfacies within the Asmari Formationof the Chattian timeare bioclastperforateimperforate foraminifera wackestone-packstone and mudstone, of an inner ramp depositional setting. The Miogypsina-Elphidium sp. 14-Peneroplis farsensis assemblage zone (Aquitanian) ipresent in High Zagros, Izeh, Dezful Embayment and parts of the Fars and Lurestan provinces. The dominated microfacies within the Asmari Formation of the Aquitanian time are perforateimperforate foraminifera bioclastwackestone-packstone, grainstone and mudstone, of an inner ramp depositional setting. The Borelismelocurdica-Borelismelomelo assemblage zone (Burdigalian) is present in most areas. But it slightly occurs in Fars province. The microfacies of the Asmari Formation during Burdigalian are similar to those of Aquitanian. In Sepid-Dasht and Tang-e Anbar Sepid sections due to presence Globigerina spp. assemblage zone and planktonic foraminifera wackestone-packstonefacies, an outer ramp depositional setting is also suggested.