نتایج جستجو برای: Benthic foraminifera

تعداد نتایج: 15528  

Journal: :geopersia 0
mehdi sarfi school of earth sciences, 36716-41167 damghan, iran mohsen yazdi-moghadam national iranian oil company exploration directorate, sheikh bahayi square, 1994814695 tehran, iran

a micropaleontological study has been carried out on the samples collected from the sarv abad section, the oldest and only known jurassic sedimentary rocks cropping out in the moghan area. studied sequence consists of carbonates bounded at both base and top by clastic deposits. studied carbonate deposits provide an assemblage of benthic foraminifera as well as calcareous algae. the stratigraphi...

Journal: Geopersia 2016

A micropaleontological study has been carried out on the samples collected from the Sarv Abad section, the oldest and only known Jurassic sedimentary rocks cropping out in the Moghan area. Studied sequence consists of carbonates bounded at both base and top by clastic deposits. Studied carbonate deposits provide an assemblage of benthic foraminifera as well as calcareous algae. The stratigraphi...

2006
Kunio Kaiho Kotaro Takeda Maria Rose Petrizzo James C. Zachos

Paleocene–Eocene warming and changes in oceanic hydrography should have significantly impacted the ecology of marine microorganisms, both at the surface and on the seafloor. We analyzed several key characteristics of foraminifera from two Shatsky Rise (ODP Leg 198) cores spanning the P/E boundary including the maximum test diameters of the largest calcareous trochospiral benthic foraminifera an...

Journal: Geopersia 2017

AbstractThe Aitamir Formation is divided into two members the lower sandstone and the upper shale. 32 genera and 57 species of foraminifera have been recognized. According to identified foraminifera Rotalipora appenninica Interval Zone, Rotalipora globotruncanoides (Rotalipora brotzeni) interval zone and Whiteinella aumalensis-Dicarinella canaliculata assemblage zone are proposed and a l Albian...

Journal: Geopersia 2016
Farzaneh Barani Felix Schlagintweit, Koorosh Rashidi

The larger benthic foraminifera Gyroconulina columellifera Schroeder & Darmoian, 1977 (type-locality: Maastrichtian Aqra Formation of Iraq) is described for the first time from two sections of the Maastrichtian Tarbur Formation of the Zagros Fold-Thrust-Belt, SW Iran. New details on its wall microstructure are provided. The microfacies is represented by bioclastic wacke-/pack-/grainstones with ...

Journal: Geopersia 2016

Study of a late Late Santonian to Late Campanian hemipelagic succession from Abtalkh Formation at the Bahadorkhan section (Central Kopet-Dagh) enabled us to verify paleoecology changes based on planktonic and benthic foraminifera assemblage. Bahadorkhan section is consisted of calcareous shale, lime marl, marl, and a few dispersed chalky limestone beds. Upper and lower boundaries of Abtalkh For...

Journal: :Marine pollution bulletin 2013
L R Pettit M B Hart A N Medina-Sánchez C W Smart R Rodolfo-Metalpa J M Hall-Spencer R M Prol-Ledesma

Extensive CO2 vents have been discovered in the Wagner Basin, northern Gulf of California, where they create large areas with lowered seawater pH. Such areas are suitable for investigations of long-term biological effects of ocean acidification and effects of CO2 leakage from subsea carbon capture storage. Here, we show responses of benthic foraminifera to seawater pH gradients at 74-207m water...

Journal: :geopersia 0
felix schlagintweit koorosh rashidi payame noor university, po box 19395-3697 tehran farzaneh barani payame noor university, po box 19395-3697 tehran

the larger benthic foraminifera gyroconulina columellifera schroeder & darmoian, 1977 (type-locality: maastrichtian aqra formation of iraq) is described for the first time from two sections of the maastrichtian tarbur formation of the zagros fold-thrust-belt, sw iran. new details on its wall microstructure are provided. the microfacies is represented by bioclastic wacke-/pack-/grainstones with ...

2006
R NIGAM

Changes in coiling direction in foraminifera have been used extensively as proxy data for paleoclimates. However, most of the studies centred around plantkonic foraminifera, and various causes (including reproductive mode) were suggested for coiling direction changes. We explored the relationship between mode of reproduction and coiling directions in benthic foraminifera. Benthic foraminiferal ...

Journal: :رخساره های رسوبی 0
رضوان دهقان امرالله صفری

the qom formation in ghohrud area, have been investigated in order to determine its biostratigraphy and palaeoecology. the thickness of qom formation is 325 meters at the study area and consists of thin, medium to thick bedded and massive limestons. they underline on eocene volcanic with disconformably and its upper boundary is overlain by alluvium. based on thin section studies 14 genera and 2...

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