- Tytuł:
- Identification of the Oligocene-Miocene boundary in the Central Iran Basin (Qom Formation) : Calcareous nannofossil evidences
- Autorzy:
-
Parandavar, Mohammad
Hadavi, Fatemeh - Powiązania:
- https://bibliotekanauki.pl/articles/2058670.pdf
- Data publikacji:
- 2019
- Wydawca:
- Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
- Tematy:
-
Oligocene-Miocene boundary
calcareous nannofossils
biohorizons
Central Iran Basin
Qom Formation
“c1” Sub-member - Opis:
- A diverse Late Oligocene to Early Miocene calcareous nannofossil assemblage was examined from the Qom Formation in the Central Iran Basin, and the Oligocene-Miocene boundary was identified based on the quantitative analysis of the assemblages in 303 smear slides. Eleven well-established calcareous nannofossil bio-events are delineated in the Upper Oligocene through Lower Miocene. The results clearly show that the Highest Occurrence (HO) of Sphenolithus delphix is the closest bio-event to the boundary as traditionally delineated on the lithostratigraphic criteria, and provides a distinct biohorizon below it. The Lowest Occurrence (LO) of the species Discoaster druggii is the oldest Miocene bio-event that is observed shortly after the HO of S. delphix, showing that calcareous nannofossils are well suited for approximating the Oligocene-Miocene boundary in the Qom Formation. The Oligocene-Miocene boundary is placed in the upper part of Sub-member “c1” in all three sections studied here and it is traceable throughout the Central Iran Basin, which makes a potentially reliable marker horizon for sequence stratigraphic and hydrocarbon studies in the area.
- Źródło:
-
Geological Quarterly; 2019, 63, 2; 215--229
1641-7291 - Pojawia się w:
- Geological Quarterly
- Dostawca treści:
- Biblioteka Nauki
Artykuł