JOURNAL OF STRATIGRAPHY AND SEDIMENTOLOGY RESEARCHES
Year:2016 | Volume:32 | Issue:2 (63)|Papers Count:8

The Ghorban Member of the Sachun Formation (Paleocene-early Eocene) at type section in south east Shiraz composed of limestone, dolomitic limestone and dolomite.This carbonate member has been affected by various diagenesis processes in marine, meteoric and burial digenetic environment. Result of this study indicates that botryoidal aragonite and bladed calcite cements and micritic envelope are the product of marine phreatic diagenetic environment. Anhedral dolomicrite with fenestral porosity and absence of fossils has been formed in marine vadose diagenetic environment. Mixing zone of marine and phreatic water in the Jahrum and the Sachun Formations boundary has provided favorable conditions for formation of porous dolosparite. Oxidation conditions of meteoric vadoze has played important role for oxidizing of outcropped sediment that subsequently have been transported to basin as oxidizing extra clast and bioclasts. Products of meteoric phreatic diagenetic environment include dissolution, neomorphism, silicification and dog tooth, blocky and drusy calcite cements. Diagenetic processes of burial environment include physical and chemical (stylolite) compaction, drusy calcite cement along with dolosparite and dolomicrosparit. Results of uplifting of succession and exposure to the surface had been accompanied with fracture and calcite veins development, dissolutionand iron oxide in iron bearing sediments.

In recent decades, the subject of gas emission in underground coal mines in many countries is an important subject. Many factors affect in gas emissions in coal seams.Geological and physical structures of coal are affecting on gas emissions'.Also, composition and mineralization of coal, affect in coal permeability for different gases. In this study, the relationship between maceral composition and coal permeability in Tazareh and Parvadeh mines has been studied. Accordingly, a laboratory studies to investigate the relationship between coal composition and coal permeability was done. In coal samples, with MFORR equipment the permeability test was done. With microscopic analysis, the maceral contents of coal such as Inertinite and Vitrinite have been measured. Accordingly, many coal samples of Parvadeh and Tazareh coal mines have the pyrite as the dominant mineral matter. Parvadeh coal samples has the average percentage of Vitrinite equal 81.34% and 10.52% Inertinite. Also, in the Tazareh coal samples in Eastern Alborz coal mines, the average percentage of Vitrinite is 69.31% and inertinite is 22.47%.The average percentage of Pyrite content in Parvadeh coal samples in Tabas coal mines is 2.38% and in the Tazareh coal samples in Eastern Alborz coal mines is 2.62%. The permeability test results have been shown, which, with increase of Inertinite contents, the permeability of coal is increasing. Also, test results have been shown, there was a reduction in the coal permeability with increasing of mineral contents and carbonate contents of the coal. So, the coal permeability in Tabas coal samples is more than Eastern Alborz coal samples.

For studying of biostratigraphy of Mishan Formation in Bandar Abbas hinterland, a stratigraphic transection including Handun, Anguru, Baviyun, and Nakh sections was selected in northwest and west of Bandar Abbas. A total 668 samples investigated from Mishan Formation which 515 hard and 153 soft samples. The Mishan Formation consists mainly of massive to thin bedded limestones and thin bedded argillaceous limestone and green to grey marls. The Guri Member at the bottom of the Mishan Formation, overlies siliciclastic rocks of the Razak Formation or evaporate deposits of Gachsaran Formation and lie under the brown conglomerate and sandstone of the Agha Jari Formation. Generally, at the base of sections, based on presence of benthonic foraminifera such as Meandropsina iranica, Meandropsina anahensis, Borelis melo curdica the age of sections was determined as Burdigalian and only at 17 m of base of Nakh section due to absence of Burdigalian index foraminifera, belongs to Aquitanian which it corresponds to the strontium isotope analysis.The age of upper parts of the sections due to the presence of planktonic foraminifera such as Praeorbulina glomerosa, Orbulina suturalis, Orbulina universa, is suggested Langhian. Burdigalian age was determined based on foraminifera contents only in stratigraphic section of Nakh, that corresponds to the strontium isotope analysis. In this study, planktonic foraminifera taxa such as O. universa, O. suturalis, P.transitoria and P. glomerosa are reported for the first time from Guri Member in Handun section.

Paleontological studies lead to recognition of 21 genera and 16 species of benthic foraminifera, 5 genera and 6 species of planktonic foraminifera and 3 genera and 3 species of oligosteginids. The vertical distribution of fauna lead to identification of 5 biozones including: Favusella washitensis Range Zone, Oligostegina Assemblage Zone, Rudist debris Zone, Nezzazata-Alveolinids Assemblage Zone, Nezzazatinella-Dicyclina Assemblage Zone. Based on the indicated biozones, the age of the Sarvak Formation is Late Albian to Early Turonian in the study area. Eleven carbonate facies belonging to four environments including tidal flat, restricted and semi-restricted lagoon, shoal and open marine are recognized. The identified facies are deposited on the homoclinal ramp setting.Based on the vertical changes of facies and recognized depositional environments, four third-order depositional sequences are represented. The transgressive systems tracts mainly comprises of open marine facies including sponge spicule, oligosteginid, echinoid and benthic foraminifera, while the highstand systems tracts mainly consists of shoal facies rich in bioclast, and restricted and semi-restricted lagoon facies rich in porcellaneous and hyaline benthic foraminifera and peloid. The maximum flooding surface represented by open marine facies including echinoid and planktonic foraminifera.

The main objective of the present study is to evaluate variation, contamination and speciation of heavy metals in bed sediments of the Siahrood River in Mazandaran Province. For this purpose, fifteen sediment samples were collected along the main channel of the river. In addition to total content of heavy metals and selected physiochemical properties of the sediments, geochemical species of heavy metals were determined operationally using the modified BCR method. The obtained results generally showed that there is a wide variation in heavy metal concentrations in the sediments, probably due to anthropogenic inputs into the river and effect of physicochemical properties of the sediments (organic matter and clay content) on the heavy metals variability. The calculated Igeo (Geo-accumulation index) for each metal also revealed that sediments are moderately or strongly contaminated in terms of Pb and Cd whereas not or slightly contaminated with respect to other heavy metals, suggesting an anthropogenic source for Pb and Cd and a mostly geogenic origin for Ni, Zn, and Cr (Arsenic is probably of a mixed source). The results of BCR method indicated that Pb and Cd are predominately incorporated into the first fraction (F1, acid-soluble fraction) while Zn and Ni are mainly associated with residual fraction (F4) confirming the concluded remarks on discrimination of heavy metals origins in the sediments.

The Oligocene-Miocene Qom Formation was deposited in different thickness in the Central Iran, Urumiehh–Dokhtar magmatic arc and Sanandaj–Sirjan provinces in Iran. The Oligocene-Miocene Kahak section of the Qom Formation in the Urumiehh–Dokhtar magmatic arc has been studied, in order to biostratigraphic data of the large benthic foraminifera.In the Kahak section, the foraminifera assemblages of the Qom Formation consist of Nummulites fichteli, Nummulites vascus, Eulepidina dilitata, Nephrolepidina sp., Neprolepidina tournoueri, Eulepidina sp., Pseudolituonella reicheli, Miogypsina sp., Miogypsina irregularis, Amphistegina sp., Operculina sp., Bozorginella qumiensis, Triloculina trigonula, Triloculina tricarinata, Peneroplis sp., Peneroplis thomasi, Dendritina ranji, Triloculina trigonula, Rotalia sp., Pyrgo sp., Elphidium sp., Borelis melo and Borelis curdica.In the Kahak section of the Qom Formation, four assemblage biozones of the large benthic foraminifera have been recognized from Rupelian, Chattian, Aquitanian and Burdigalian stages. These biozones are similar to assemblage biozones of the Oligocene-Miocene Asmari Formation in the Zagros Basin in southwest of Iran. Distribution type of the Oligocene-Miocene foraminifera in the Kahak depositions of the Qom Formation indicates to depositional settings of the lagoon, open lagoon and shallow open marine paleoenvironments. There is some similarity of foraminifera assemblage in Qom Formation sediments with other locality of Tethys including Mediterranean and Indo-West Pacific.