نتایج جستجو برای: Calcareous nannofossils

تعداد نتایج: 3502  

Elham Mojtahedin, Fatemeh Hadavi, Razyeh Lak,

The objective of this study is to understand the calcareous nannoplankton response to past environmental changes in the Strait of Hormuz during the Holocene. Calcareous nannoplankton is well abundant in the living phytoplankton community and a key component of the marine sediments. Due to its distinct reaction to environment changes and its good preservation potential, it is well suited for p...

Akram Pouresmaeil, Fatemeh Hadavi, Razieh Lak,

The effect of the paleoclimatic and paleoenvironmental changes on the structure of the bioticcommunities are stronger and better recorded in the shelf area than in the open sea. The present study isdevoted to impact of climatic events on some species of calcareous nannofossils. For this reason, 17samples of surface sediments of the Persian Gulf were studied. Preservation of calcareous nannofoss...

Journal: :دیرینه شناسی 0
مرضیه نطقی مقدم فاطمه هادوی بهنام رحیمی

in present study, diversity and relative abundance of calcareous nannofossils of the boundary between abtalkh and neyzar formations in dobaradar, kalat and chahchaheh sections were studied. taxonomical studies of calcareous nannofossils in the studied areas led to identification of 24 species in dobaradar, 27 species in kalat and 32 species in chahchaheh sections. based on identified nannofossi...

ژورنال: اقیانوس شناسی 2020

In this research, paleoecology of Baghmashah Formation in Rizu section based on calcareous nannoplanktons has been investigated. Baghmashah Formation is part of the Mago sedimentary mega sequence in the Tabas block that was located in the northern margin of the Neotethys Ocean in Jurassic-Cretaceous. The Baghmshah Formation in this section with 270m thickness mainly includes the alternation of...

2017
David K. Watkins G. Villa

Rare calcareous nannofossils from the Cape Roberts Project drillhole CRP-2A indicate that this area was episodically invaded by marginal oceanic surface waters during the late and late early Oligocene. These depauperate assemblages lack most of the biostratigraphic index fossils for the Oligocene, but do provide two datums that aid in constraining the age of the section: the last appearance dat...

Journal: :journal of tethys 0

calcareous nannofossil assemblages of the boundary paleocene-eocene deposits (pabdeh formation) of the zagros, dezful embayment-mansouri oilfield have been studied in detail. it consists of shale and grey marlstone with inter layers of calcareous argillites and marly claystone. we present a study focused on changes in calcareous nannofossils of the pabdeh formation during the paleocene/eocene b...

Journal: :رخساره های رسوبی 0
فرح جلیلی فاطمه هادوی مرضیه نطقی مقدم

for biostratigraphic studies, based on calcareous nannofossils, a thickness of 480 meters of cretaceous deposits in shushud section (north birjand) has been measured and sampled. the studied section is composed of shale, marl, marine sandstone and sandy limestone. the shale and marl units were more suitable for sampling. according to taxonomical studies, 10 genera and 25 species in shushud sect...

Journal: :Fountain Journal of National ad Applied Sciences 2023

Biostratigraphic analysis was carried out on KA-1 well, onshore Niger Delta Basin of Nigeria. A total forty (40) ditch cutting samples were collected from the studied section at 30 feet depth intervals with ranging 7590-4800feet. The objectives this study are to determine age and biozonation section. Using simple smear slide method, processed analyzed for nannofossils using a reflected binocula...

A calcareous nannofossils biostratigraphic study has been carried out on the chalky limestones located in South Gorgan, north of Iran. The study is aimed at determining the age and nannofossil biozonations of the well. The samples were prepared using smear slide technique. Thirty seven calcareous nannofossils species were identified and used to make biostratigraphic zonations and dating of the ...

Journal: Journal of Tethys 2017

In this study, the assemblage of calcareous nannofossils has been investigated in long and continuous deposits from a Kafaz section in Eastern Iran. A systematic study of calcareous nannofossils has indicated 39 nannofossils species. In order to the age determination of Kafaz's deposits, a revised zonation for the Eocene is used. Based on it, the Early-Middle Eocene deposits of Kafaz section is...

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