Evaluation of Structural Patterns and Related Alteration and Mineralization Zones by Using ASAR-ASTER Imagery in Siyahrood Area (East Azarbaijan—NW Iran)

The NW part of Iran belongs to the Iranian plateau that is a tectonically active region within the Alpine-Himalayan orogenic belt. The intrusion of Oligocene parts in various faces caused the alteration and mineralization such as copper, molybdenum, gold and iron in the Siyahrood area. Granitoidic rocks with component of Granodiorite to alkali have been influenced by hydrothermal fluids. Alteration zones are important features for the exploration of deposits and the ASTER sensor is able to identify the type of alteration and its alteration zoning. This method can be a useful tool for detecting potential mineralization area in East Azarbaijan—Northwest of Iran. The purpose of this study is to evaluate ASTER data for mapping altered minerals in Siyahrood area in order to detect the potential mineralized areas. In this study, false color composite, and band ratio techniques were applied on ASTER data and argillic, phyllic, Iron oxide and propylitic alteration zones were separated. ASAR image processing has been used for lineaments and faults identified by the aid of directional filter. The structural study focused on fracture zones and their characteristics including strike, length, and relationship with alteration zones. The results of this study demonstrate the usefulness of remote sensing methods and ASTER multi-spectral data for alteration, and ASAR data are useful for lineament mapping.

A systematic step-wise approach for shale gas assessment in undeveloped prospects:A case study of Lurestan shale gas area in Iran

Key parameters and evaluation methods of shale gas show that it is not possible to guarantee the commercial and economic development of shale gas by sorting out geological sweet spots only according to technical indicators.A research method combining technical indicators including total organic carbon content and vitrinite reflectance with economic indicators including internal rate of return and investment payback period is proposed to screen the best technological and economic development sweet spots in undeveloped areas.This method was used to evaluate the best technological and economic development sweet spots in Cretaceous shale gas reservoirs S_(1) and S_(2) of Lurestan area,Iran.Twenty-one geologic sweet spots were picked out based on effective reservoir thickness,vitrinite reflectance and gas content.Based on analogy method,the pressure gradient,clay mineral content,buried depth and other parameters were taken as comparative indicators,the Eagle Ford shale as comparison object,recovery factor and production curve were extracted to estimate the technologically recoverable reserves of the study area.On this basis,the economic indexes such as internal rate of return and investment payback period were used to evaluate the economy of the geological sweet spots.In the case of P_(10) distribution,the total technologically recoverable reserves and economically recoverable reserves are 7875×10^(8)m^(3) and 4306×10^(8)m^(3) respectively,11 geological sweet spots have commercial development value,among which,No.1 sweet spot has the highest value,with a net present value of 35×10^(8) USD.

Evaluation of Drought Hazard Area of GharehAghaj Basin in Iran, Using GIS

In GharehAghaj basin drought has the most profound effect on the way of living and regional economy. Drought Hazard by nature is a result of interrelated parameters concerned. The objective of this paper presents a model to assess hazard of drought using the Geographical Information System (GIS). The data analyzed have been gathered from the records, reports and maps published by the governmental offices of Iran. Various drought hazard indicators have different severity classification in different models. The drought hazard indicator maps take into account the meteorological, hydrological, physical and socioeconomic characteristics that related to drought hazard. Each of the hazard indicator maps and also final hazard map are classified into 4 hazard classes of drought: mild, moderate, severe and very severe. The final hazard classes were defined on the basis of hazard scores arrived at by assigning the appropriate attributes to the indicators and the final hazard map was prepared by overlaying different hazard indicator maps in the GIS, deploying the new model. The final Hazard Map shows that moderate hazard areas (89.87% of the basin) are much widespread than areas under severe hazard (10.13% of the basin) which are observed in the Southeast of the region.

Contribution of biophysical and climate variables to the spatial distribution of wildfires in Iran

This study investigated the relationship between climate and biophysical variables in burned areas in Iran.The fire burned area(FBA)product(Fire CCI 5.1.1),land surface temperature(MOD11C3C),vegetation index(MOD13A1),and climate variables such as temperature,wind speed,relative humidity,and volumetric soil moisture from the ERA5 reanalysis dataset were used.Pearson correlation coefficient was used to determine the relationship between biophysical and climate variables and fire occurrence.The results show that FBA increased by 1.7 hectares/decade from 2001 to 2020.The high FBA in 2010(the black summer of Iran)was due to high temperatures and significant heatwaves that led to extensive wildfires.Although anthropogenic activities are considered a significant cause of wildfires,several variables,including increased temperatures,less precipitation,relative humidity,and wind speed and direction,contribute to the extent and occurrence of wildfires.The country’s FBA hotspot is in the Arasbaran region during the summer season.Temperature and relative humidity are the most significant variables influencing the occurrence of wildfires.The results show the vulnerability of Iran s forests and their high potential for fires.Considering the frequency of fire occurrences in Iran and the limited equipment,fire prevention plans should be carried out by applying proper management in high-risk regions.

Parasitic contamination of surface and deep soil in different areas of Sari in north of Iran

Objective:To study the parasitic contamination of soil in selected areas of Sari,north of Iran.Methods:A cross-sectional study was conducted to identify all available parasites in surface and deep soil.In this study 580 soil samples(278 deep soil and 302 topsoil samples)from 21 different locations were collected from pathways,parks,greenhouses,estates around the city,cemetery,main squares,farmlands,fenced gardens and seashores.Depending on the soil type,two samples were prepared,from surface and deep soil at the depth of 3 to 5 cm.After performing various stages of preparation,including cleaning and washing,smoothing and flotation,parasitic elements were examined microscopically and quantitative parasite counting was done using a McMaster slide.Results:The results showed that the highest rate of parasitic contamination was related to nematodes larvae(26.11%).Other contaminants such as Entamoeba and Acanthamoeba cysts,vacuolization Blastocystis hominis form,oocyte containing sporocysts,Toxascaris eggs,nematoda larvae,Hymenolepis eggs,Ascaris eggs,Fasciola eggs,hookworm eggs,Toxocara eggs,insects'larvae and other ciliated and flagellated organisms were also observed.The results of this study showed that the highest contamination was found in public garden(25.80%)both in surface(29.30%)and in deep soil(21.12%),while the lowest level of contamination was observed in seashore surface soil(4.90%).Conclusions:The results showed that soil can provide a potential medium for the spread of soil transmitted parasitic diseases in the environment;therefore,preventive programs are needed.

Shale gas potential of the lower Silurian hot shales in southern Iran and the Arabian Plate: Characterization of organic geochemistry

A significant phase of global warming appeared during the Llandovery and productive Silurian hot shale was preserved all over the world.The lower Silurian shale is the main effective source rock for most of the Paleozoic hydrocarbon in Iran and the Arabian platform.Silurian hot shales have become prospective resources for new energy such as shale gas.The regional distribution and shale gas potential of the lower Silurian hot shale in southern Iran and the Arabian plate are determined using outcrops and exploration well samples data from previous studies.The studied area has a high organic content(on average more than 2%),maximum burial depth is 5300 m,shale thickness of 30-200 m,organic matter maturities(most comparable),clay minerals content ranging from 20%to 57%,quartz content ranges from 20%to 49%,feldspar content ranges from 10%to 15%and calcite content ranges from 1.48%to 5%which all favor shale gas generation and accumulation.We concluded that southern Iran and east-central Saudi Arabia are two of the most sustainable and favorable locations for shale gas exploration and production for lower Silurian hot shale after assessing all of the key characteristics.

Implementing conceptual model using renewable energies in rural area of Iran

In a glance,more than three billion people live in the rural areas of low and middle income countries.In most cases,rural households have many unmet energy needs including cooking,lighting,heating,transportation and telecommunication needs.The main goal of this study is Implementing Conceptual Model Using Renewable Energies in Rural Area of Iran.In this study,the Weibull and Angestrom distribution methods were used to assess the potential of wind and solar energy range in Chaharmahal va Bakhtiari province of Iran(The Case study).After determining the values calculated based on meteorological stations’data,the IDW interpolation method in GIS software was used for the entire geographic range of the province.After reviewing multiple regions and identifying potential classes,a village which has the potential to be enough sun and wind energy was selected(Kahkesh village)and then a field survey based on biomass resources was accomplished.The needs of rural residents and rural renewable energy potential was evaluated by study conceptual frameworks during one year.By dividing the value of frameworks energies the amount of energy saving can be calculated.Finally,it recommended that for utilizing the renewable energies in rural areas,as will be discussed in the present work and particularly using the conceptual frameworks,is performed.

伊朗Kashan地区古近系库姆组层序地层及盆地演化特征

库姆组沉积时期伊朗Kashan地区为中伊朗盆地库姆盆地东南方向的弧后边缘海盆地，以浅海相的碳酸盐岩和碎屑岩沉积为主。受构造运动与全球海平面旋回变化控制，大部分地区的库姆组形成了5个三级层序S1～S5，上覆上红组底部蒸发岩层，在这5个三级层序之下，盆地沉降中心位置还可见SOa和SOb层序。对格架中层序地层特征的动态演化分析后认为，Kashan地区在库姆组及其上、下地层沉积时期经历了7次重要的地层演化阶段：低水位充填期、初次海侵期、沉降充填期、孤立泻湖期、再次海侵期、构造抬升期、完全孤立期。

伊朗Kashan地区新生代前陆盆地构造演化特征

利用Kashan地区横穿盆地的地震剖面资料, 应用平衡剖面技术恢复了Kashan地区自晚渐新世以后各个时期的构造, 认为中伊朗地区自晚始新世以来经历了弧后残留海盆地 (晚渐新世—早中新世)、前陆盆地雏型 (早中新世—中新世), 前陆盆地成型 (晚中新世—上新世) 和前陆盆地定型 (第四纪 ) 4个阶段. 现今为一典型的弧后前陆盆地, 由山前冲断褶皱带、山前凹陷带、前缘隆起带、斜坡带构成.

伊朗Kashan地区库姆组沉积相及其对储层的控制作用

伊朗Kashan地区库姆组形成于混水碳酸盐岩台地沉积环境,以碳酸盐岩与陆源碎屑岩的混合沉积为主,沉积特征受陆源碎屑的影响较大。库姆组自身储集条件偏差,裂缝和溶孔在储集空间中占绝对优势,断裂活动及相伴生的溶蚀活动是控制储层发育的主要因素,而沉积相则为之提供物质基础。有利储集相带主要分布在应力集中区域和岩石破裂地区,其中局限台地滩相和三级层序界面之下的岩溶带是最佳储层发育位置。

中伊朗盆地Kashan地区油气地质条件研究

通过野外地质调查和地质—地球物理—地球化学的综合研究,详细剖析了Kashan区块的油气地质条件。其主要目的层中晚渐新世—早中新世的库姆组为世界上极具特色的含陆源碎屑—火山碎屑的碳酸盐岩混积地层,又是典型的裂缝-孔隙型储层。中伊朗盆地为一弧背前陆盆地,其内构造圈闭发育。由于泥质岩和膏岩发育,Kashan地区油气保存条件极佳。中伊朗盆地Kashan地区发育有侏罗系Shemshak组、白垩系和库姆组海相页岩和泥灰岩3套烃源岩,但质量欠佳。Arn-2井和Fkh-21井分别有过3期和4期含烃流体充注。Arn-22井和Fkh-21井所充注的并不是与Arn-21井类似的液态石油而是富氮或不含氮的天然气。建议在中伊朗盆地其他区块的油气勘探中,把烃源岩的质量评价、油气资源前景估计和储层裂缝预测放在研究工作的首要位置。

伊朗卡山地区侏罗系Shemshak组烃源岩特征研究

该文通过对伊朗卡山地区侏罗系Shemshak组烃源岩有机质丰度、干酪根镜鉴结果、干酪根碳同位素特征、生物标志化合物特征等的分析,提出Shemshak组烃源岩干酪根类型主要为腐泥-腐殖型(Ⅱ2)和腐殖(Ⅲ)型。有机质演化大部分样品已达到过成熟阶段。Shemshak组烃源岩除了极少部分属好烃源岩以外,大部分为中等烃源岩。

中伊朗盆地卡尚地区库姆组层序地层研究

利用野外露头、钻井和地震资料,通过岩相、沉积旋回以及地震层序和地震相分析建立中伊朗盆地库姆组的层序地层系统、框架模式及沉积体系,岩性地层单元与沉积层序的对应关系。研究发现库姆组沉积于一个受全球海平面升降变化及区域构造活动影响而与波斯湾间歇性相通的弧后大陆边缘海盆地,是一顶底面以不整合界面为界的构造层序(超层序组),其内部发育3个3级层序。依据库姆组沉积时的盆地形态和沉积环境分析将盆地分为岛弧、台地、斜坡、盆地4个次级构造-沉积单元。盆地南缘为障壁岛,由于陆源碎屑少,南带及中带沉积碳酸盐岩为主;而北东缘为陆地,陆源(火山)碎屑供应充分,发育扇、河控三角洲沉积体系;东南岛弧带则沉积碳酸盐岩夹火山碎屑岩为主。

伊朗卡山探区Aran背斜圈闭的地球物理综合评价

针对伊朗卡山探区勘探程度低、周期短、难度大、风险高的特点 ,通过地球物理资料 ,特别是地震资料的处理和解释 ,结合探区外围的地质调查和油气田资料 ,进行了油气藏圈闭可靠性、储集封堵条件、有效性及含油气性等方面的地球物理资料预测 ,探索出了一套早期勘探区域圈闭评价的新方法。利用该方法对该探区的 Aran背斜圈闭进行了综合评价 。

伊朗卡尚地区始新世沟鞭藻类

文章简要报道了伊朗卡尚地区库姆组首次发现的沟鞭藻类 ,计 6属 6种。根据沟鞭藻化石组合面貌 ,并结合介形虫和钙质超微化石组合 ,探讨了含沟鞭藻化石的地层时代 ,推测其沉积环境为正常浅海大陆架环境。

中伊朗盆地卡山地区Aran构造带油气成藏

中伊朗盆地卡山地区Aran构造带已钻探井3口,其中Arn-1井获工业性油气流,随后勘探失利。为了揭示该构造带在Arn-1井和Arn-2井地区的构造差异,分析勘探失利的原因,通过对Aran构造带过井地震剖面的构造演化分析,明确了构造运动与圈闭形成和烃源岩生烃时间与空间的匹配关系;并根据流体地化性质探讨了Aran构造带油气成藏特征。研究结果表明,Arn-1井和Arn-2井地区都经历了相同的构造运动,但库姆组沉积末期的构造运动使Arn-2井地区遭受抬升剥蚀;Arn-2井库姆组中所充注的流体,均来自于寄主围岩以外的库姆组自身,未捕获到侏罗系油气;Aran构造带主要形成了库姆组"自生自储"油气藏。

伊朗卡尚地区古近纪介形类的发现

本文简要报道了发现于伊朗卡尚地区古近系的介形类 ,计 16属 6种、8比较种、9未定种及 1亲近种。根据介形类化石组合面貌 ,并结合钙质超微、沟鞭藻和有孔虫化石组合 ,认为含介形类化石的地层时代为始新世至渐新世 ,推测其沉积环境为正常浅海大陆架环境 ,而且为温暖浅海内陆架。

伊朗卡山探区Aran背斜圈闭的地球物理综合评价

在低勘探程度区,往往由于缺乏地下地质资料,对钻井的部署缺乏信心。本文针对伊朗卡山探区勘探程度低、周期短、难度大、风险高的特点,力图通过地球物理资料特别是二维地震资料的多种处理和解释,结合工区周边的地质调查以及油气田资料,对其圈闭的可靠性、储集条件、有效性以及含油性等方面作出全面的地球物理资料预测,为探索一套勘探早期圈闭评价的新方法提供技术支持。

伊朗卡山地区库姆组储层特征及控制因素分析

渐新统—中新统库姆组海相碳酸盐岩是伊朗卡山地区目前最有利的一套储层,且已获得了高产工业油气流。通过钻井、测井、地质、地球物理等方法,对这套储层进行了系统的研究和评价,结果发现,库姆组储层以台地相生物灰岩为主,有效储集空间为溶孔和裂缝,孔隙类型是裂缝+孔隙型,具有双重介质特征。利用地震属性分析、波阻抗反演等方法,对库姆组有利储层的分布进行了平面上的预测,发现有利储层主要分布在断裂、构造发育部位和褶皱的转折端,但平面上和垂向上都具有强非均质性,认为沉积环境、成岩作用和构造活动是控制该区储层发育的3个主要因素。

地震资料采集中的最大干扰距离计算

在2个或2个以上的地震队同时在一个地区进行野外地震资料采集的情况下,一个地震队所激发的地震波往往会干扰另一个地震队所接收的地震信息。这就引出一个最大干扰距离的概念,即一个地震队激发的地震波能量不被另一个地震队所接收的最短距离。很明显,最大干扰距离与震源类型和激发条件有关。讨论了最大干扰距离计算的方法原理,即利用实际地震资料,计算炮记录各道的均方根振幅,利用幂函数拟合得到振幅随炮检距变化的衰减曲线,结合背景噪声记录的均方根振幅,求出最大干扰距离。在伊朗AMK工区的三维地震勘探中,中国和伊朗的2个地震队同时在这一区域进行地震资料采集工作,为了避免出现相互干扰的情况。利用上述方法分别计算了炸药震源和可控震源的最大干扰距离,并进行了采集试验。结果表明,当2个队施工的距离大于最大干扰距离时,同时进行资料采集不会产生相互干扰,由此说明以上方法是合理可行的。