Pub Date : 2020-10-01DOI: 10.30495/IJES.2020.677467
R. Haftlang, M. Afghah, A. Aghanabati, M. P. Shirazi
Two stratigraphic sections (Kuh-e-Rahmat and Kuh-e-Sabz) of Upper Cretaceous strata in the Interior Fars region (SW of Iran) were selected. Lower Cretaceous succession of Kuh-e-Rahmat was consisted of Dariyan, Kazhdumi Sarvak and Ilam Formations. The lower contact of the Sarvak Formation with Kazhdumi Formation is described as a transitional type whereas the upper contact of Sarvak Formation was not clear. Stratigraphic distribution of microfossils reveals three biozones in this section: 1: Palorbitolina lenticularis (Aptian), 2: Orbitolina concava and Hemicyclamina sigali (late Albian-early Cenomanian), 3: Stomiosphaera conoidea (Late Cenomanian-Early Turonian). Kuh-e-Sabz lithologic aspect consists of two rock units such as: Sarvak Formation and thin-bedded limestone of lower part of Ilam Formation. The lower contact of the Sarvak Formation was not clear whereas the upper contact with Ilam Fm. was exposed as an erosional disconformity including oxidized zone. Vertical distribution of investigated taxa supports three biozones: 1: Taberina bingistani zone (middle Cenomanian), 2: Praelveolina cretacea zone (late Cenomanian), 3: Dicyclina schlumbergeri zone (Santonian-Campanian). The Sarvak Formation of Kuh-e-Rahmat was deposited in an inner shelf paleoenvironment (as open marine facies) because of well distributed of pelagic fauna, while Kuh-e-Sabz section mostly shows reef facies (back reef-fore) along the platform including agglutinated and porcelaneous foraminifera which reflects an inner shallow platform (0-50m).
{"title":"Biostratigraphy correlation, of Cretaceous successions in Kuh-e-Rahmat and Kuh-e-Sabz sections, NE Shiraz, Zagros (SW Iran)","authors":"R. Haftlang, M. Afghah, A. Aghanabati, M. P. Shirazi","doi":"10.30495/IJES.2020.677467","DOIUrl":"https://doi.org/10.30495/IJES.2020.677467","url":null,"abstract":"Two stratigraphic sections (Kuh-e-Rahmat and Kuh-e-Sabz) of Upper Cretaceous strata in the Interior Fars region (SW of Iran) were selected. Lower Cretaceous succession of Kuh-e-Rahmat was consisted of Dariyan, Kazhdumi Sarvak and Ilam Formations. The lower contact of the Sarvak Formation with Kazhdumi Formation is described as a transitional type whereas the upper contact of Sarvak Formation was not clear. Stratigraphic distribution of microfossils reveals three biozones in this section: 1: Palorbitolina lenticularis (Aptian), 2: Orbitolina concava and Hemicyclamina sigali (late Albian-early Cenomanian), 3: Stomiosphaera conoidea (Late Cenomanian-Early Turonian). Kuh-e-Sabz lithologic aspect consists of two rock units such as: Sarvak Formation and thin-bedded limestone of lower part of Ilam Formation. The lower contact of the Sarvak Formation was not clear whereas the upper contact with Ilam Fm. was exposed as an erosional disconformity including oxidized zone. Vertical distribution of investigated taxa supports three biozones: 1: Taberina bingistani zone (middle Cenomanian), 2: Praelveolina cretacea zone (late Cenomanian), 3: Dicyclina schlumbergeri zone (Santonian-Campanian). The Sarvak Formation of Kuh-e-Rahmat was deposited in an inner shelf paleoenvironment (as open marine facies) because of well distributed of pelagic fauna, while Kuh-e-Sabz section mostly shows reef facies (back reef-fore) along the platform including agglutinated and porcelaneous foraminifera which reflects an inner shallow platform (0-50m).","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43157776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-01DOI: 10.30495/IJES.2020.677469
Hamidreza Saeeidi, G. Lashkaripour, M. Ghafoori
The development of agriculture and industry and the increase of population in countries with arid to semi-arid climates have led to more harvesting of groundwater resources and as a result land subsidence in different parts of the worlds. Decades of groundwater overexploitation in the Kashmar-Bardaskan plain in the north-east of Iran has resulted substantial land subsidence in this plain. The plain is considered as an arid to semi-arid zone and facing a negative water balance. The average annual precipitation in the plain is around 191 mm and the evaporation rate is 3956 mm. According to the unit hydrograph of the plain, the annual decline of water level is 1.12 m. In this study, the velocity of subsidence has been determined using Interferometric SAR technique (In-SAR) and radar images of Envisat ASAR and Sentinel-1 for a time period from 2003 to 2017. The results of an InSAR time series analysis indicated that an area of 1200 km2 with different speeds of 5 to 26 cm/year in the satellite line of sight (LOS) is subsiding. The results showed that in addition to the decline of groundwater level, subsurface conditions such as sediments types (fine-grained layers) and their thickness also affect the occurrence and amount of land subsidence.
{"title":"Evaluation of land subsidence in Kashmar-Bardaskan plain, NE Iran","authors":"Hamidreza Saeeidi, G. Lashkaripour, M. Ghafoori","doi":"10.30495/IJES.2020.677469","DOIUrl":"https://doi.org/10.30495/IJES.2020.677469","url":null,"abstract":"The development of agriculture and industry and the increase of population in countries with arid to semi-arid climates have led to more harvesting of groundwater resources and as a result land subsidence in different parts of the worlds. Decades of groundwater overexploitation in the Kashmar-Bardaskan plain in the north-east of Iran has resulted substantial land subsidence in this plain. The plain is considered as an arid to semi-arid zone and facing a negative water balance. The average annual precipitation in the plain is around 191 mm and the evaporation rate is 3956 mm. According to the unit hydrograph of the plain, the annual decline of water level is 1.12 m. In this study, the velocity of subsidence has been determined using Interferometric SAR technique (In-SAR) and radar images of Envisat ASAR and Sentinel-1 for a time period from 2003 to 2017. The results of an InSAR time series analysis indicated that an area of 1200 km2 with different speeds of 5 to 26 cm/year in the satellite line of sight (LOS) is subsiding. The results showed that in addition to the decline of groundwater level, subsurface conditions such as sediments types (fine-grained layers) and their thickness also affect the occurrence and amount of land subsidence.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41605033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.30495/IJES.2020.674671
Amir Saffari, F. Sereshki, M. Ataei
There are several phenomenons for polluting the environment, especially in coalfields; which coal spontaneous combustion is one of them. The moisture content is one of the intrinsic characteristics of coal, which has an important role in the occurrence of this phenomenon. Therefore, this research predicts the coal spontaneous combustion tendency based on moisture content. The percentage of moisture content is a very important parameter on the occurrence of this process; so far a conclusion about the effect of moisture content on coal spontaneous combustion, a comprehensive study was done. 55 coal samples with different percentage of moisture content for the training of overall underground coalfields in Iran were collected and the CPT test method for each coal sample was carried out. Then, the method of regression analysis was used for modeling and predicting the coal spontaneous combustion tendency. The results show, the coal sample undergoes oxidation most rapidly when the moisture content supply is about under 20%, and it can reduce coal spontaneous combustion in excessed of 20%, because when moisture is present in excessed of 20%, the heat released by oxidation is used to evaporate the moisture. For validation and testing, 15 coal samples of another coalfield were collected and the CPT test method for each coal sample was carried out, and the results of the test method were compared by the regression equation. The results obtained from the models show that a good appropriate prediction has been done for determining the coal spontaneous combustion tendency by regression analysis.
{"title":"A comprehensive study on the effect of moisture content on coal spontaneous combustion tendency","authors":"Amir Saffari, F. Sereshki, M. Ataei","doi":"10.30495/IJES.2020.674671","DOIUrl":"https://doi.org/10.30495/IJES.2020.674671","url":null,"abstract":"There are several phenomenons for polluting the environment, especially in coalfields; which coal spontaneous combustion is one of them. The moisture content is one of the intrinsic characteristics of coal, which has an important role in the occurrence of this phenomenon. Therefore, this research predicts the coal spontaneous combustion tendency based on moisture content. The percentage of moisture content is a very important parameter on the occurrence of this process; so far a conclusion about the effect of moisture content on coal spontaneous combustion, a comprehensive study was done. 55 coal samples with different percentage of moisture content for the training of overall underground coalfields in Iran were collected and the CPT test method for each coal sample was carried out. Then, the method of regression analysis was used for modeling and predicting the coal spontaneous combustion tendency. The results show, the coal sample undergoes oxidation most rapidly when the moisture content supply is about under 20%, and it can reduce coal spontaneous combustion in excessed of 20%, because when moisture is present in excessed of 20%, the heat released by oxidation is used to evaporate the moisture. For validation and testing, 15 coal samples of another coalfield were collected and the CPT test method for each coal sample was carried out, and the results of the test method were compared by the regression equation. The results obtained from the models show that a good appropriate prediction has been done for determining the coal spontaneous combustion tendency by regression analysis.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43377156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.30495/IJES.2020.674668
A. Ojo, Mubor Adeloye, I. Egbedele, Feyisayo Akinwande
Geomagnetic study was carried out to investigate the distribution and depth of formations of different magnetic rocks on an old quarry site, Abeokuta, Southwestern, Nigeria. Eight ground magnetic profiles were established with 10 m spacing intervals orientated in West-East and North-South directions, and ranged between 110 and 190 m. A total of 223 data sets were acquired and corrected for all forms of magnetic variations. The resulting residual anomalies were plotted against distance using Microsoft Excel tool. Also, these anomalies were modeled into 2D and 3D contour sections using Surfer 10. The depth to basement analysis was carried out using Peter’s half slope graphical method. The resulting profiles and contour sections revealed variable anomalies which indicated contrast in the magnetic distributions of the subsurface. Mineral rocks with average (0-150 nT) magnetic susceptibilities dominated the profiles, and this indicated that the study area is on pegmatite or Quartz vein which probably harbored Beryl, Graphite, Sandstone, Quartz, Tantalite and Mica in both massive and disseminated quantities. Regions with high (150-300 nT) and low (0 to -150 nT) magnetic susceptibilities were also observed across the profiles. Mineral rocks with very thin bodies were observed at depths 3.48-17.42 m, intermediate bodies were buried at depths 2.61-13.06 m, while very thick bodies were located at depths between 2.09 and 10.45 m. The depth of the magnetic sources revealed that the major and minor mineral rock contact in the study area.
{"title":"Magnetic rocks distribution and depth to basement analysis on an old Quarry Site, Abeokuta, SW Nigeria","authors":"A. Ojo, Mubor Adeloye, I. Egbedele, Feyisayo Akinwande","doi":"10.30495/IJES.2020.674668","DOIUrl":"https://doi.org/10.30495/IJES.2020.674668","url":null,"abstract":"Geomagnetic study was carried out to investigate the distribution and depth of formations of different magnetic rocks on an old quarry site, Abeokuta, Southwestern, Nigeria. Eight ground magnetic profiles were established with 10 m spacing intervals orientated in West-East and North-South directions, and ranged between 110 and 190 m. A total of 223 data sets were acquired and corrected for all forms of magnetic variations. The resulting residual anomalies were plotted against distance using Microsoft Excel tool. Also, these anomalies were modeled into 2D and 3D contour sections using Surfer 10. The depth to basement analysis was carried out using Peter’s half slope graphical method. The resulting profiles and contour sections revealed variable anomalies which indicated contrast in the magnetic distributions of the subsurface. Mineral rocks with average (0-150 nT) magnetic susceptibilities dominated the profiles, and this indicated that the study area is on pegmatite or Quartz vein which probably harbored Beryl, Graphite, Sandstone, Quartz, Tantalite and Mica in both massive and disseminated quantities. Regions with high (150-300 nT) and low (0 to -150 nT) magnetic susceptibilities were also observed across the profiles. Mineral rocks with very thin bodies were observed at depths 3.48-17.42 m, intermediate bodies were buried at depths 2.61-13.06 m, while very thick bodies were located at depths between 2.09 and 10.45 m. The depth of the magnetic sources revealed that the major and minor mineral rock contact in the study area.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48576796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.30495/IJES.2020.674672
M. Javanbakht, M. Poursoltani, Naser Kholghi
The Kordkanlo Basin, one of the Atrak sub-basins, located in the northeastern of the Ghoochan city, the Khorasan Razavi Province; is situated in Kopet Dagh geologic zone. The overall objective of this study is to evaluate the morphotectonic effects on the drainage network of the basin, using morphometric indicators. In this research, morphometric quantitative indicators of hypsometric integral (H), the ratio of the valley area to the an area of half-circle with a radius equal to the valley depth (V), the ratio of the width of valley floor to a height of the river (VF), asymmetry factor (AF), the river’s length gradient index (SL), transverse topography symmetry factor (T) and index of mountain front sinuosity (SMF), the basin shape index (BS) and the index of (Lat) have been used. This purpose tries to identify the role of change in lithological and tectonic agents on the Kordkanlo river basin using topographic maps, digital elevation model (DEM) and the information obtained in the field survey. In this context, ArcGIS software has been used for determining geomorphic indicators to determine the tectonic characteristics of the basin. Finally, index values were evaluated by the lat index. The result reveals high tectonic activity in the study area.
{"title":"Use of morphometric indices in drainage network changes (Indicators in the Kordkanlo Basin)","authors":"M. Javanbakht, M. Poursoltani, Naser Kholghi","doi":"10.30495/IJES.2020.674672","DOIUrl":"https://doi.org/10.30495/IJES.2020.674672","url":null,"abstract":"The Kordkanlo Basin, one of the Atrak sub-basins, located in the northeastern of the Ghoochan city, the Khorasan Razavi Province; is situated in Kopet Dagh geologic zone. The overall objective of this study is to evaluate the morphotectonic effects on the drainage network of the basin, using morphometric indicators. In this research, morphometric quantitative indicators of hypsometric integral (H), the ratio of the valley area to the an area of half-circle with a radius equal to the valley depth (V), the ratio of the width of valley floor to a height of the river (VF), asymmetry factor (AF), the river’s length gradient index (SL), transverse topography symmetry factor (T) and index of mountain front sinuosity (SMF), the basin shape index (BS) and the index of (Lat) have been used. This purpose tries to identify the role of change in lithological and tectonic agents on the Kordkanlo river basin using topographic maps, digital elevation model (DEM) and the information obtained in the field survey. In this context, ArcGIS software has been used for determining geomorphic indicators to determine the tectonic characteristics of the basin. Finally, index values were evaluated by the lat index. The result reveals high tectonic activity in the study area.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41880631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.30495/IJES.2020.674670
L. Fazli, S. Senemari
The Gurpi, Tarbur and Sachun formations have been investigated in the studied section in the Fars Province, in order to determine their sequence stratigraphy. On the basis of done studies on the cores of borehole, four main microfacies have been recognized in four stratigraphic sequence deposited during the Campanian to Maastrichtian. The lowermost sequence, was deposited in the early Campanian-early late Campanian which include wackestone to packestone texture with Globotruncanita elevata Zoneand Globotruncana ventricosa Zonethatrepresentative of the deep marine and outer ramp. The intermediate and uppermost sequences (sequences two, three and four) display well developed deposits formed in the end of the Campanian (Radotruncana calcarata Zoneand Globotruncanella havanensis Zone), formed during the Maastrichtian (Globotruncana aegyptiaca Zoneand Gansserina gansseri Zone) and the end of the Maastrichtian (Omphalocyclus macroporus - loftusia sp assemblage Zone) on pelagic, hemipelagic, outer and middle ramp. On the basis of the sequence stratigraphic chart, the transgression of the upper Cretaceous sea started since the early Campanian and continued gradually until the early Maastrichtian. Then, until the end of Maastrichtian, the area has been emerged. The sequence stratigraphic architecture of Campanian/ Maastrichtian Gurpi, Tarbur and Sachun formations model is in a good agreement with global sea level changes.
{"title":"Earliest Campanian - latest Maastrichtian sequence stratigraphy based on planktonic foraminifera, Fars province, Zagros, Iran","authors":"L. Fazli, S. Senemari","doi":"10.30495/IJES.2020.674670","DOIUrl":"https://doi.org/10.30495/IJES.2020.674670","url":null,"abstract":"The Gurpi, Tarbur and Sachun formations have been investigated in the studied section in the Fars Province, in order to determine their sequence stratigraphy. On the basis of done studies on the cores of borehole, four main microfacies have been recognized in four stratigraphic sequence deposited during the Campanian to Maastrichtian. The lowermost sequence, was deposited in the early Campanian-early late Campanian which include wackestone to packestone texture with Globotruncanita elevata Zoneand Globotruncana ventricosa Zonethatrepresentative of the deep marine and outer ramp. The intermediate and uppermost sequences (sequences two, three and four) display well developed deposits formed in the end of the Campanian (Radotruncana calcarata Zoneand Globotruncanella havanensis Zone), formed during the Maastrichtian (Globotruncana aegyptiaca Zoneand Gansserina gansseri Zone) and the end of the Maastrichtian (Omphalocyclus macroporus - loftusia sp assemblage Zone) on pelagic, hemipelagic, outer and middle ramp. On the basis of the sequence stratigraphic chart, the transgression of the upper Cretaceous sea started since the early Campanian and continued gradually until the early Maastrichtian. Then, until the end of Maastrichtian, the area has been emerged. The sequence stratigraphic architecture of Campanian/ Maastrichtian Gurpi, Tarbur and Sachun formations model is in a good agreement with global sea level changes.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41304841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.30495/IJES.2020.675578
Mahsa Khosaravi, S. Saadat, R. Dabiri
The study area is located in North Eastern Iran, near Taknar copper deposit where exploration, extraction and processing operations are ongoing. The purpose of this study is to understand the geochemical effects of mining activities in Taknar area and to evaluate the contamination of soil and water resources with heavy metals. The results of pollution indices such as CF, Igeo and EF and multivariate (geo)statistical analysis indicate anthropogenic source for Cu and Se elements, mostly related to mining and mineral processing activities, natural origin of Cr, Ni and Co and both anthropogenic and natural origin for Zn, Pb, Cd, As, Sb and Mo elements. The results also indicate the water and soil of the flotation plant and mining tunnels can be harmful. Fortunately, the water resources used by the staff, downstream aqueduct of the mine and the water of the villages in the south of the mine are free of contaminated elements.
{"title":"Evaluation of heavy metal contamination in soil and water resources around Taknar copper mine (NE Iran)","authors":"Mahsa Khosaravi, S. Saadat, R. Dabiri","doi":"10.30495/IJES.2020.675578","DOIUrl":"https://doi.org/10.30495/IJES.2020.675578","url":null,"abstract":"The study area is located in North Eastern Iran, near Taknar copper deposit where exploration, extraction and processing operations are ongoing. The purpose of this study is to understand the geochemical effects of mining activities in Taknar area and to evaluate the contamination of soil and water resources with heavy metals. The results of pollution indices such as CF, Igeo and EF and multivariate (geo)statistical analysis indicate anthropogenic source for Cu and Se elements, mostly related to mining and mineral processing activities, natural origin of Cr, Ni and Co and both anthropogenic and natural origin for Zn, Pb, Cd, As, Sb and Mo elements. The results also indicate the water and soil of the flotation plant and mining tunnels can be harmful. Fortunately, the water resources used by the staff, downstream aqueduct of the mine and the water of the villages in the south of the mine are free of contaminated elements.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41721995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-01DOI: 10.30495/IJES.2020.673333
H. Mansouri, A. S. Bafti, M. Pourkermani
According to numerous studies, there are basic and initial scaling relationship for the geometric and kinematic characteristics of faults. The study area is located in the northern part of the Kerman coal province. The statistical calculations are consisting of: measure the surface density of faults per unite area and division of the area, determining the direction of the dominant faulting and evaluating the relationship between length-displacement, strike-displacement and strike-length. Based on diagrams, the highest fracture density is related to the middle portion (B zone) of study area because that enclosed between the four main faults and sandstone rock assemblage. The relationship between strike-length parameter is calculated as (y=0.0478x + 11.54), and R-squared rate is (R=0.341), strike-displacement is calculated as (y=2.68x + 147.4) and R-squared rate is (R=0.65) and length-displacement is calculated as (y= 243.58 x0.0336) and R-squared rate is (R=0/022). It was determined that increasing the density of fractures and faulting in the study area can be attributed to the complex geological structure, the formation of initial faults and long term progressive deformation. Due to deformations accumulation and formations of multiple structures (like faults, folds and shear zones), have Increasing the fracture density, and topography, and has interacted with together. Comparison the length-strike and strike-displacement parameters, represents a similarity on the clustering in the plotted data Despite that they have many similarities to each other, does not show a dependable dependence, this may indicate their asynchronous creation.
{"title":"The power law scaling, geometric and kinematic characteristic of faults in the Northern part of the Kerman Coal Province (KCP), Iran","authors":"H. Mansouri, A. S. Bafti, M. Pourkermani","doi":"10.30495/IJES.2020.673333","DOIUrl":"https://doi.org/10.30495/IJES.2020.673333","url":null,"abstract":"According to numerous studies, there are basic and initial scaling relationship for the geometric and kinematic characteristics of faults. The study area is located in the northern part of the Kerman coal province. The statistical calculations are consisting of: measure the surface density of faults per unite area and division of the area, determining the direction of the dominant faulting and evaluating the relationship between length-displacement, strike-displacement and strike-length. Based on diagrams, the highest fracture density is related to the middle portion (B zone) of study area because that enclosed between the four main faults and sandstone rock assemblage. The relationship between strike-length parameter is calculated as (y=0.0478x + 11.54), and R-squared rate is (R=0.341), strike-displacement is calculated as (y=2.68x + 147.4) and R-squared rate is (R=0.65) and length-displacement is calculated as (y= 243.58 x0.0336) and R-squared rate is (R=0/022). It was determined that increasing the density of fractures and faulting in the study area can be attributed to the complex geological structure, the formation of initial faults and long term progressive deformation. Due to deformations accumulation and formations of multiple structures (like faults, folds and shear zones), have Increasing the fracture density, and topography, and has interacted with together. Comparison the length-strike and strike-displacement parameters, represents a similarity on the clustering in the plotted data Despite that they have many similarities to each other, does not show a dependable dependence, this may indicate their asynchronous creation.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41932309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-01DOI: 10.30495/IJES.2020.673336
M. B. Golpasand, Seyyed Ghafour Alavi, A. Rezaei
The load entering from the ground surrounding on the tunnel’s lining is one of the effective parameters in the designation of a tunnel. The amount of this parameter, which is called Rock load in a rocky environment, depends on several factors such as the overburden thickness, geological and geomechanical conditions and the depth of tunnel. In the present study, the amount of rock load for the Lot 2 of Imamzadeh Hashem Tunnel (L2IHT) has been evaluated using various methods and the effect of geological characteristics of the rock units on the tunnel route has been investigated. For this purpose, different methods for estimating the rock load were introduced firstly, and then the amount of this parameter for the tunnel was estimated using these methods. To evaluate the thickness of the plastic zone around the tunnel, the numerical method, finite difference code of FLAC3D software, has been used. Comparison of the results obtained from different methods and their analysis indicates that the rock load applying from H-4 and H-10 rock units is more than the other units. This happens because of the specific geological characteristics of these rock units such as high degree of crushing due to the geological factors and being in the faulted zone. Therefore, it is required for the stronger lining of the tunnel in the range of these units.
{"title":"The effect of engineering geology on the rock load and squeezing potential in Lot2 of Imamzadeh-Hashem tunnel","authors":"M. B. Golpasand, Seyyed Ghafour Alavi, A. Rezaei","doi":"10.30495/IJES.2020.673336","DOIUrl":"https://doi.org/10.30495/IJES.2020.673336","url":null,"abstract":"The load entering from the ground surrounding on the tunnel’s lining is one of the effective parameters in the designation of a tunnel. The amount of this parameter, which is called Rock load in a rocky environment, depends on several factors such as the overburden thickness, geological and geomechanical conditions and the depth of tunnel. In the present study, the amount of rock load for the Lot 2 of Imamzadeh Hashem Tunnel (L2IHT) has been evaluated using various methods and the effect of geological characteristics of the rock units on the tunnel route has been investigated. For this purpose, different methods for estimating the rock load were introduced firstly, and then the amount of this parameter for the tunnel was estimated using these methods. To evaluate the thickness of the plastic zone around the tunnel, the numerical method, finite difference code of FLAC3D software, has been used. Comparison of the results obtained from different methods and their analysis indicates that the rock load applying from H-4 and H-10 rock units is more than the other units. This happens because of the specific geological characteristics of these rock units such as high degree of crushing due to the geological factors and being in the faulted zone. Therefore, it is required for the stronger lining of the tunnel in the range of these units.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70076548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-01DOI: 10.30495/IJES.2020.673335
M. Sedghi, A. Dorostian, M. Zare, M. Pourkermani
Understanding strong ground motions in the near-fault areas is important for seismic risk assessment in densely populated areas. In the past, lack of information on strong ground motion for large and moderate earthquakes led to the use of mainly far field large and moderate earthquake records in equations for calculation of the strong ground motion parameters. In this article, we collected and generated a seismic catalogue with a data set of corrected and processed 217 triaxial near source strong ground motion and accelerometric data recorded from 1976 to 2018 obtained from 30 shallow crustal earthquakes with a focal depth below 30 km from different regions including 24 in Iran, 5 in California and one in Italy (because of the lack of Iranian near-field accelerograms) in different stations. These data were recorded (129 Iranian records, 88 from California and Italy) with a source-to-site distance less than 80 km and earthquakes between Mw = 5 and 7.5. Receiver function method was used for site classification for these records. The percentage of processed data in this study was 18%, 43%, 33% and 6% for the different site classes of 1, 2, 3, and 4. In the final catalog, records in which their PGA≥ 100 cm /s2, were reported. This near source ground motion database also contains information about ground motion, source parameters and is fundamental for dynamic research in earthquake engineering for the estimation of strong ground motion parameters (PGA, PGV, PGD and frequency content of response spectra) of moderate-to-large earthquakes.
{"title":"A Strong Ground Motion Catalogue of Selected Records for Shallow Crustal, Near Field Earthquakes in Iran","authors":"M. Sedghi, A. Dorostian, M. Zare, M. Pourkermani","doi":"10.30495/IJES.2020.673335","DOIUrl":"https://doi.org/10.30495/IJES.2020.673335","url":null,"abstract":"Understanding strong ground motions in the near-fault areas is important for seismic risk assessment in densely populated areas. In the past, lack of information on strong ground motion for large and moderate earthquakes led to the use of mainly far field large and moderate earthquake records in equations for calculation of the strong ground motion parameters. In this article, we collected and generated a seismic catalogue with a data set of corrected and processed 217 triaxial near source strong ground motion and accelerometric data recorded from 1976 to 2018 obtained from 30 shallow crustal earthquakes with a focal depth below 30 km from different regions including 24 in Iran, 5 in California and one in Italy (because of the lack of Iranian near-field accelerograms) in different stations. These data were recorded (129 Iranian records, 88 from California and Italy) with a source-to-site distance less than 80 km and earthquakes between Mw = 5 and 7.5. Receiver function method was used for site classification for these records. The percentage of processed data in this study was 18%, 43%, 33% and 6% for the different site classes of 1, 2, 3, and 4. In the final catalog, records in which their PGA≥ 100 cm /s2, were reported. This near source ground motion database also contains information about ground motion, source parameters and is fundamental for dynamic research in earthquake engineering for the estimation of strong ground motion parameters (PGA, PGV, PGD and frequency content of response spectra) of moderate-to-large earthquakes.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45523547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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