Microbiostratigraphy of the Upper Paleocene to Middle Eocene Jahrum Formation in the Folded Zagros Zone, SW Iran

2015 ◽  
Vol 25 (7) ◽  
pp. 759-770 ◽  
Author(s):  
S. Izadighalati ◽  
V. Ahmadi
Lithos ◽  
2021 ◽  
Vol 388-389 ◽  
pp. 106060
Author(s):  
Bhupati Neupane ◽  
Junmeng Zhao ◽  
Babu Ram Gyawali ◽  
Yan Deng ◽  
Bishal Maharjan ◽  
...  

2020 ◽  
pp. 57-67
Author(s):  
Felix Schlagintweit ◽  
Koorosh Rashidi

new larger benthic foraminifera is described as Broeckinella hensoni from the upper Maastrichtian Tar-bur Formation of SW Iran (Zagros Zone). In comparison to the type species of the genus, Broeckinella arabica Henson, which also occurs in the Tarbur Formation, the new species has distinctly larger dimensions (e.g., size and thickness of test, chamber height). The first record of a microspheric specimen of B. arabica shows previously unrecorded annular chambers in the final test stage. Therefore, the generic diagnosis is herein emended. In the Tarbur Formation, both B. hensoni n. sp. and B. arabica occur in foraminiferal-algal wackestones. However, B. arabica occurs in a wider range of microfacies, including packstones and grainstones. It is assumed that Broeckinella originated in the Upper Cretaceous with Broeckinella neumannae Gendrot. The upper Albian Broeckinella aragonensis Peybernès is herein transferred to the porcellaneous genus Peneroplis Montfort.


2020 ◽  
Author(s):  
Nilya Bengül

<p>The Haymana Basin in central Anatolia (Turkey) formed during the closure of the Neo-Tethys on Late Cretaceous to Middle Eocene as a forearc accretionary wedge. Late Paleocene to Middle Eocene aged units in this basin are exposed near Çayraz Village, Haymana. The Çayraz Formation is the youngest unit of the Haymana Basin, and it is represented by packages of nummulitic banks, and the intercalation of calcareous mudstones. The aim of this study is to investigate the sedimentary cyclicity and depositional sequences in the Upper Paleocene- Eocene successions of the Haymana Basin. To be able to achieve this objective, a stratigraphic section has been measured through this succession. In this study, detailed microfacies analyses of the shallow-water carbonate successions indicate a ramp type depositional model of the carbonate rocks. The facies composed of Alveolina sp., Orbitolites sp., and  Miliolids that indicate low energy depositional environment . After that depositional environment to  the shoal; the facies composed of Nummulites spp., Assilina spp. occur and increase their abundance towards high-energy environments. Absence of the Alveolina sp., Orbitolites sp., and Miliolids. occur in accordance with that. The facies composed of Nummulites spp., Assilina spp. become associated with Discocyclina sp. towards to open sea on the ramp, and the shallow open marine part is represented by the shale with the association of planktonic foraminifera. Lateral relationships of the facies from proximal (inner ramp) to the distal (mid ramp) part of the ramp are investigated by using the knowledge of paleoecology preferences of the fossils, lithologic data of the rocks and biological aspects of the fossils.  The fossil associations and their indicator environments can be used in vertical changes of the facies as in the lateral relationships of the facies. It has potential to derive cyclic relationships of the stratigraphic sequence. Therefore, based on the detailed microfacies analysis and change in the distribution of the fossil associations in the stacking pattern of the sequence, a composite depositional model has been suggested. At this part of the research newly acquired question is that the driven factor of these cyclic relationships of the sequence, whether it occurred by the control of the eustatic sea- level or the interplay between tectonics and the eustacy as the dominating factor in the sequence formation.</p><p> </p><p>Keywords: Large Benthic Foraminifera, Nummulites spp., Assilina spp., Haymana Basin, Çayraz Formation</p>


1993 ◽  
Vol 71 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Kathleen B. Pigg ◽  
Ruth A. Stockey ◽  
Suzette L. Maxwell

Paleomyrtinaea princetonensis gen. et sp.nov. Pigg, Stockey & Maxwell is described from the Middle Eocene Princeton Chert of British Columbia, Canada. Anatomically preserved fruits are berries up to 1.6 × 0.78 cm with a fleshy fruit wall that consists of a three-layered pericarp. The exocarp is composed of a uniseriate epidermis of tabular cells and an outer hypodermis of small cells and the mesocarp is aerenchymatous. Some seeds are invested in a pulpy endocarp. The seeds are campylotropous, 1.8 mm long and 1.6 mm wide, and contain a curved embryo cavity about 1.5 mm long and 0.64 mm wide. Four distinct integumentary zones can be recognized, an outermost zone two to three cells thick of tangentially elongate cells, a second zone, constituting the bulk of the integument, of small, isodiametric cells, a third zone of uniseriate, columnar cells that extends into the germination valve, and an innermost zone of five to six layers of tangentially elongate cells. The genus is also represented by fruits and seeds from the Upper Paleocene Sentinel Butte Formation, Almont, North Dakota. Affinities of these fruits are with the berrylike guavas of the Myrtaceae, tribe Myrteae, subtribe Myrtinae, and in particular, with the closely related genera Mosiera Small and Psidium L. A brief review of the fossil record of the Myrtaceae is also presented. Key words: Myrtales, Myrtaceae, Tertiary, permineralization, fruit, seed.


1994 ◽  
Vol 68 (2) ◽  
pp. 274-278 ◽  
Author(s):  
Charles R. Givens ◽  
Christopher L. Garvie

Morphometric analysis demonstrates that Strepsidura ficus (Gabb) of Harris (1895), from the lower middle Eocene Reklaw and Queen City Formations of Texas, is specifically distinct from Whitneya ficus Gabb (1864) of the Californian Eocene. Accordingly, the new name Strepsidura harrisi is proposed for the Texas species. Strepsidura s.s. is represented in North America by S. ficus (Gabb), S. harrisi n. sp., and an unnamed species closely related to S. harrisi in the upper Paleocene Sequin Formation of Texas. Strepsidura s.s. apparently originated in the Old World Tethyan Realm during the Paleocene and subsequently spread to North America.


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