2024-03-29T01:03:58Z
https://geopersia.ut.ac.ir/?_action=export&rf=summon&issue=7841
Geopersia
2228-7817
2228-7817
2016
6
2
First record of Gyroconulina columellifera Schroeder & Darmoian, 1977 (larger benthic foraminifera) from the Maastrichtian Tarbur Formation of SW Iran (Zagros Fold-Thrust-Belt)
Felix
Schlagintweit
Koorosh
Rashidi
Farzaneh
Barani
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 benthic foraminifera (e.g., Loftusia ssp., Neobalkhania bignoti, Omphalocyclus macroporus) and dasycladalean algae. The Iranian discoveries give further evidence for the biostratigraphic importance of the taxon. The biostratigraphy of the Tarbur Formation based on larger benthic foraminifera is reviewed and critically discussed. Both Gyroconulina columellifera Schroeder & Darmoian, and the dasycladale Pseudocymopolia anadyomenea (Elliott), which have been first described from the Maastrichtian of Iraq, are now also reported from the Tarbur Formation of Iran. Their restricted occurrences along the southeastern northern margin of the Arabian plate and the Taurides of Turkey (Anatolian plate) are indicative for a Late Cretaceous provincialism, partly coinciding with the larger Loftusia bioprovince.
Benthic Foraminifera
Dasycladales
Zagros Zone
Biostratigraphy
Palaeobiogeography
2016
07
01
169
185
https://geopersia.ut.ac.ir/article_58675_1c1a83e5f0d075979d12adb7a9834c1a.pdf
Geopersia
2228-7817
2228-7817
2016
6
2
Stratigraphy of the Upper Jurassic shallow marine carbonates of the Moghan area (NW Iran), with paleobiogeography implication on Alveosepta jaccardi (Schrodt, 1894)
Mehdi
Sarfi
Mohsen
Yazdi-Moghadam
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 stratigraphic distribution of the larger benthic foraminifera, particularly, almost consistent present of Alveosepta jaccardi allowed us to propose an age of Late Oxfordian to Early Kimmeridgian for the studied succession. At this time, Paratethys Basin was at very beginning of its opening. Larger benthic foraminifera and inhabited fauna at this basin are in close similarity with Tethyan Realm association. Data provided by larger foraminifera, calcareous algae, and microfacies analysis may suggest an environment of warm shallow water with low to medium energy regime
Paratethys
Moghan
Late Jurassic
Stratigraphy
Larger benthic foraminifera
Alveosepta jaccardi
2016
07
01
187
196
https://geopersia.ut.ac.ir/article_59089_2b43a58861f98e29f14f6a0490fc9d1b.pdf
Geopersia
2228-7817
2228-7817
2016
6
2
The “South Gondwana Fauna” in the Jurassic – an example of the utility of marine Ostracods for palaeobiogeography and palaeogeographic researches
Parvaneh
Rezaei Roozbahani
The present article is a review of a palaeobiogeographic analysis of Jurassic Ostracods from East Africa, India and Madagascar and includes also some general remarks on palaeobiogeography, biodiversity and Ostracod ecology.The palaeobiogeographic study shows the high significance of this microfossil group for the reconstruction of palaeogeographic processes, particularly plate tectonic developments and sea level changes. The “South Gondwana Fauna” (SGF) was established in the early Middle Jurassic in a shallow marine rift basin between Madagascar, India and East Africa (Gulf of Madagascar) which was a result of early rifting processes between East- and West Gondwana. The maximum diversity of this fauna was reached during the late Middle Jurassic due to geographic expansion of the basin caused by successive rifting and rising sea level. The strong endemic character of the fauna was related to the peripheral geographic position of the Gulf of Madagascar at the southern Tethyan margin. In the late Middle and Upper Jurassic the SGF shows a biogeographic separation between East Africa and Madagascar/India and increasing endemism which may be affected by a deepening of the gulf and/or by the appearance of other environmental migration barriers between these areas.
Palaeobiogeography
Palaeobiodiversity
Jurassic
Ostracods
Gondwana
Plate Tectonics
2016
07
01
197
209
https://geopersia.ut.ac.ir/article_58879_3b9ed0ebae518a2d68cd8eaf3aa7f366.pdf
Geopersia
2228-7817
2228-7817
2016
6
2
Biostratigraphy of the Gurpi Formation in Sepidan section, Interior Fars basin based on planktonic foraminifera
Hassan
Rameh
MohammadJavad
EsfandyariBayat
In this study biostratigraphy of the Upper Cretaceous deposits (Gurpi Formation) in Sepidan section located in the Interior Fars basin (SW Iran) was studied. The Gurpi Formation in this section consists of 360 m lime shale, argillaceous limestone and shale laid continuously on the Ilam Formation and with a paraconformity under the Pabdeh Formation. Nine genera and 27 species of planktonic foraminifera have been identified in the section. On this basis, the Gurpi Formation here includes nine biozones with an age of Santonian to Maastrichtian. The biozones identified resemble considerably those of the other parts of the world.
Biostratigraphy
Gurpi Formation
Interior Fars basin
Upper Cretaceous
2016
07
01
211
221
https://geopersia.ut.ac.ir/article_58673_3f4545f2dac739692c9636598f4eb8dc.pdf
Geopersia
2228-7817
2228-7817
2016
6
2
Biogeochemical exploration in Sari Gunay gold deposit, Northwestern Iran
Behzad
Mehrabi
Hassan
Alimohamdai
Mahin
Farhadian Babadi
Farrokh
Ghahremani Nejad
Biogeochemistry is a useful tool for assessing geochemical dispersion patterns. Sari Gunay epithermal gold deposit was selected in order to assess the application of biogeochemical exploration for gold in northwestern Iran. In this study, four sites were sampled in a profile perpendicular to mineralized vein with a control site two km far-off mineralized vein. A sample from each dominant plant species (Silene conoidea, Achillea aleppica, Crepis corniculata, Centaurea virgata) was collected in each site and after preparation, analyzed using ICP-MS method. The results show that there is an inverse relationship between distance from mineralized vein and the concentration of gold and its associated elements in S. conoidea and A. aleppica species. S. conoidea has higher concentration of gold (303 ppb) than other species, therefore this species is a preferable bioindicator for gold mineralization. Biological absorption coefficients for Au and its pathfinder among all three species are increased over Au mineralization vein and decrease in following order S. conoidea> A. aleppica> C. corniculata. There is a need for further investigation on using S. conoidea as an As-phytoextractor (As=163.5 ppm) in remediation for arsenic contaminated sites, which also might be helpful during mining and mineral processing in Sari Gunay and neighboring deposits.
Biogeochemical Exploration
Gold
Indicator Plant Species
Sari Gunay
2016
07
01
223
232
https://geopersia.ut.ac.ir/article_58676_94ab4c43a9db4161bdedde1a15cc5b79.pdf
Geopersia
2228-7817
2228-7817
2016
6
2
Application of the rule extraction method to evaluate seismicity of Iran
Marziyeh
Khalili
Ahmad
Zamani
Assessing seismic hazards involves specifying the likelihood, magnitude and location of earthquakes in a region. Predicting the seismic hazards is the first step in reducing the impact of the damage caused by an earthquake. In this study, to fully utilize all the known parameters which may possibly affect the occurrence of earthquakes (mb ≥ 4.5); a data-driven rule-extraction method called the Classification and Regression Tree (CART) was used to find the rules governing the earthquakes that occur. The method produces Predictive Rule Based Seismicity Map (PRBSM) of Iran that shows regions with high earthquake hazards. The rules are based on a large number of geophysical and geological parameters. The PRBSM has been built based on earthquake data from the year 1900 up to the end of 2006 and has been validated using earthquakes from 2007 to the end of 2015. In addition, this method allows for the identification of the most important combination of parameters associated with earthquakes. For example, the isostatic anomaly has the highest correlation with earthquakes in Iran. A distinctive character of this paper is the predictive rule based method which can create online as well as offline maps which are flexible and readily automated
Decision Tree
Predictive Model
Seismic Hazard Map
Iran
2016
07
01
233
242
https://geopersia.ut.ac.ir/article_58666_efe71fbf5d12131833fcf6123ba5c5e1.pdf
Geopersia
2228-7817
2228-7817
2016
6
2
Fractal dimension and earthquake frequency-magnitude distribution in the North of Central-East Iran Blocks (NCEIB)
Nasser
Naimi-Ghassabian
Mohammad-Mahdi
Khatib
Hamid
Nazari
, Mahmoud-Reza
Heyhat
The Gutenberg–Richter parameters (a and b), fractal dimension (DC), and relationships between these parameters are calculated for different regions of the North of Central-East Iran Blocks (NCEIB). The whole examined area (between 34°-36° N and 55°-61° E) is divided into 55 equal square grids. Both the a and b values for the frequency-magnitude distribution (FMD) and the fractal dimension (DC) are investigated simultaneously from 55 equal square grids. By using the completeness earthquake dataset for earthquakes of the instrumental period from 1976 to 2015, it is concluded that calculated values of a, b and DC imply variations of seismotectonic stress.The most vulnerable regions for occurrence of the large earthquakes in the NCEIB considering the computed lowest b-values and the highest DC -values. The relationships among DC -b and DC - (a/b) are used to classify the level of earthquake hazards for individual seismic source zones, in which the calibration curves illustrate a positive correlation among the DC and b values and also a positivecorrelation among the DC and a/b ratios having similar regression coefficients (R2 = 0.80 to 0.87) for both regressions. It is observed that the relationship among a/b and DC may be used for evaluation of seismicity and earthquake hazard assessment because of the high value for correlation coefficients and limited scattering of the calculated parameters
seismicity
frequency-magnitude distribution
fractal dimension
Central-East Iran Blocks
2016
07
01
243
264
https://geopersia.ut.ac.ir/article_58670_87a4980fcd951a0a4737d89d842630fc.pdf
Geopersia
2228-7817
2228-7817
2016
6
2
Karstification Potential Mapping in Northeast of Khuzestan Province, Iran, using Fuzzy Logic and Analytical Hierarchy Process (AHP) techniques
Samad
Moradi
Nasrollah
Kalantari
Abbas
Charchi
The primary objective of the current study is to produce karstification potentiality maps in northeast of Khuzestan province, Iran, using both fuzzy logic and AHP models as an additional tool in hydrogeological research. Geographic Information Systems (GIS) and Remote Sensing (RS) are used to create two maps depicting the development of the karstification, consisting of five classes, showing the karstification potentiality ranging from very high to very low. The extractions of these maps are based on the study of input data such as: lithology, lineament density, elevation, slope, rainfall, temperature, drainage density and vegetation cover. Eventually, two maps based on weighted spatial modeling system are created. The verification results show that the fuzzy logic model outperformed AHP model for the study area. Based on hydrogeological survey, hydrodynamic characteristics perceived at the outlet of major springs consisting of Dare-Anari (DA), Abshekaloo (AS) and Sarhooni (SH) revealed poorly and well developed karstified systems. The collected data indicated that one of the main factors for karst development in the area is tectonic activity and occurrence of lineaments in various scales.
Karstification potential
GIS
remote sensing
AHP
fuzzy logic
2016
07
01
265
282
https://geopersia.ut.ac.ir/article_58671_6c3cd3043d95a3a5d626d06d62468ff6.pdf
Geopersia
2228-7817
2228-7817
2016
6
2
Geochemical assessment of groundwater quality with special emphasis on fluoride in Tabasein Plain, Eastern Iran
Ahmad
Boskabady
Behnaz
Dahrazma
Mohammad
Shiva
Mohammad Hossein
Ebrahimzadeh
The aim of this research was the geochemical assessment of the groundwater quality and the evaluation of the distribution pattern of fluoride concentration in water resources of the region and their connection with the prevalence of dental fluorosis occurrence in the study area. To achieve to this goal six sediment and 22 water samples were taken and analyzed. Fluoride and phosphorous concentration were remarkably high (1400 ppm and 6231 ppm respectively) in basaltic-andesite unit. Water resources located in the southern part of old lake had the highest TDS (>6300mg/L) compared with the others. Fluoride content differ from 0.64-1.71mg/L and in 27% water samples were higher than allowable amount expressed by WHO (1.5mg/L). The health effects of fluoride were investigated on 210 students at the age of 7-16 years old. The results indicated that the fluoride concentration increased in the vicinity of the igneous rocks in water resources and also increased with the time residence. The concentration of fluoride in groundwater indicated the prevalence of dental fluorosis occurrence in the study area. The intensity of the disease revealed a meaningful correlation with the age and the male gender.
Fluoride
Fluorosis
geochemical
Groundwater
Tabasein plain
2016
07
01
283
298
https://geopersia.ut.ac.ir/article_58672_3fbbb15d6ecc6388d89e2129d545ad1e.pdf
Geopersia
2228-7817
2228-7817
2016
6
2
Equilibrium-Line Altitudes of Late Quaternary Glaciers in the Zardkuh Mountain, Iran
Babak
Ebrahimi
Abdollah
Seif
Equilibrium-line altitudes (ELAs) of former glaciers in the Zardkuh Mountain of the Zagros Mountain Range were reconstructed from glacial-geologic data on former ice limits by using various methods. In the study area various types of glacial landforms such as outwash fans, moraines and well developed glacial cirques are observed. The results suggest that ELA were depressed 1433 m below to present ELA (3067 m asl) during the maximum glacier extension. By comparison of the calculated ELA depressions (DELAs) and the amount of the ELA depression around the world, maximum glacier extension in Zardkuh was correlated with Last Glacial Maximum. The ELAs and DELAs related to youngest moraines in the study area were about 3800 and 700 m asl, respectively. The calculated DELAs are more comparable to the latest phases of Late Glaciations or first phases of Neo-glaciations. The study showed that the depression of the annual temperature during the LGM glaciations was about 9.74°C and it was about 4.76 °C probably during the youngest glaciation stage. This study shows that the former glaciers in maximum extension were mostly firn-basin glacier with valley glacier tongue which their tongues had reached to elevation about 2400 m above present sea level, during the LGM.
Last Glacial Maximum
ELA depression
Zardkuh
Zagros
Iran
2016
07
01
299
322
https://geopersia.ut.ac.ir/article_58674_63b3f8f1c11c7e0260b9a287fcf535eb.pdf