the kopet-dagh basin extended in the north and north east of iran and consists of marine strata from middle jurassic to paleogene time. abtalkh formation is one of the thickest lithostratigraphic units of cretaceous in the kopet-dagh basin and is composed of light gray, green to bluish marl and silty marl. the abtalkh formation conformably overlies the marls and chalky limestones of the abderaz...

The study of collembolan communities from the Vîşcăuți canyon in Moldova revealed 63 species belonging to 41 genera and 12 families, including four species new for the fauna of the Republic of Moldova. A checklist of collembolan species identified in the five calcareous canyons sampled so far in Moldova is included, with data on habitats, life form, occurrence and comments of distribution of mo...

On the basis of stratigraphic ranges reported calcareous nannfossils for several species, two sections Shiranish Formation from Hiran in Erbil Governorate and Smaqoli area Sulaimaniya Governorate, Northern Iraq, are analyzed. Four biozones visible examined region, grouped as follows oldest to youngest: Uniplanarius gothicus Interval zone; Tranolithus phacelosus Rienhardtites lives Micula murus ...

Calcareous tempestite levels interbedded with Ammonitico Rosso and other related pelagic facies have been recognized. The previously described examples of calcareous tempestites in pelagic facies are scarce. The studied outcrops are Middle and Late Jurassic in age and correspond to ancient sediments in the Southern Iberian Continental Paleomargin. These outcrops are now included in a notably de...

The phylogenetic relationships of the Dinophyceae (Alveolata) are not sufficiently resolved at present. The Thoracosphaeraceae (Peridiniales) are the only group of the Alveolata that include members with calcareous coccoid stages; this trait is considered apomorphic. Although the coccoid stage apparently is not calcareous, Bysmatrum has been assigned to the Thoracosphaeraceae based on thecal mo...

Calcareous sediments are located in temperate and tropical areas near offshore hydrocarbon industries and petrochemical reserves such as the Persian Gulf of Iran. These sediments have complicated physical properties which make them completely different from silicate soils. Carbonate sediments are mainly formed by the skeletal remains of marine organisms. Therefore, a wide variety of engineering...

Based on morphological and molecular data, calcareous dinoflagellates (Thoracosphaeraceae, Peridiniales) are a monophyletic group comprising the three major clades Ensiculifera ⁄Pentapharsodinium, Thoracosphaera ⁄Pfiesteria, and Scrippsiella sensu lato. We used stratigraphically well-documented first occurrences of particular archeopyle types to constrain relaxed Bayesian molecular clocks appli...

Tropical coastal marine ecosystems including mangroves, seagrass beds and coral reef communities are undergoing intense degradation in response to natural and human disturbances, therefore, understanding the causes and mechanisms present challenges for scientist and managers. In order to protect our marine resources, determining the effects of nutrient loads on these coastal systems has become ...

There are large agricultural areas in the world where wheat yields are limited by low phosphorus (P) availability. Breeding for P uptake and P utilization efficiency may reduce this problem. This study was conducted to determine the contribution of P uptake and utilization efficiency to grain yield of selected spring wheat genotypes in different environments. Thirty-eight semidwarf spring bread...

Ocean acidification represents a pervasive environmental change that is predicted to affect a wide range of species1,2, yet our understanding of the emergent ecosystem impacts is very limited. Many studies report detrimental effects of acidification on single species in lab studies, especially those with calcareous shells or skeletons3–5. Observational studies using naturally acidified ecosyste...