نشریه رسوب شناسی کاربردی
پیاپی 24 (پاییز و زمستان 1403)

As one of the branches of archaeometry, geoarchaeology deals with the application of earth sciences (geomorphology, sedimentology, soil science and stratigraphy) in solving problems related to archaeology. One of the applications of sedimentological science in archeological studies is the investigation of sedimentary petrography of ancient ceramics thin sections. The Kahnek archaeosite is located 50 meters away from Kahnek village and south of the Sarbisheh city (Southern Khorasan). In the petrographic study of the ancient pottery thin sections of this area (7 pottery samples), the pottery paste has been separated into three components: clay matrix, inclusions or additive materials, and voids. In order to determine the origin of the materials that make up the pottery of this site, the petrographic composition of the additive materials in the pottery body has been compared with soil samples of the surface of the site, gravel fragments scattered around the site, fluvial sediments and gravels adjacent to the site and geological units of the study area. The similarity of the petrographic composition of the above pottery clastic inclusions with the mentioned data proves that these ancient artefacts are local or indigenous. In this study, investigating the sedimentary petrography of Kahnek site potteries, in addition to determining the origin of pottery materials, has been used in the interpretation of manufacturing technology and firing conditions.

The present study evaluates the factors controlling the reservoir quality of this formation in one of the fields located in the eastern part of the Persian Gulf. For this purpose, the integration of sedimentological studies with petrophysical analyses has been utilized. Petrographic studies revealed that the Ilam Formation in the studied field is composed of eight sedimentary microfacies, which are deposited in inner, middle, and outer sub-environments of a ramp-like carbonate platform. The diagenetic processes affecting this formation include micritization, cementation, bioturbation, dissolution, mechanical and chemical compaction, dolomitization, neomorphism, and pyritization, occurring in marine, meteoric, and shallow to deep burial realms. The types of pores present in this formation have been classified into three scales: macro, medium, and micro, and it was found that the micropores observable in electron microscope images significantly enhance the storage capacity of this formation, especially in its lower part. Sequence stratigraphy interpretations indicated that the entire sequence of the Ilam Formation consists of a third-order sequence (comprising a transgressive systems tract and a regressive systems tract). Additionally, three fourth-order sequences were also identified. Reservoir quality analyses based on the determination of hydraulic flow units and Lorenz zonation resulted in the differentiation of 8 flow units and 10 reservoir, baffle, and barrier zones in the Ilam Formation. These flow units and reservoir zones were evaluated within the sequence stratigraphic framework, and it was found that the lower part of the Ilam Formation (the transgressive systems tract of the third-order sequence) has high storage capacity and low flow capacity, and can be considered an unconventional reservoir of the tight carbonate type. The middle part of this formation (around the maximum flooding surface) does not have significant reservoir quality, while the upper part of this formation (the regressive systems tract) with the dominance of shoal facies and partial dissolution, has high quality.

Qalikuh region of Lorestan is very important in the geology of Iran due to the spread of oil shales deposits. The Qolyan River flows in the bed of these deposits. In order to investigate the elemental geochemistry, to determine the origin and to investigate the relationship between the concentration of elements and the amount of organic matter, 15samples from the fluvial terrace sediments of the Qolyan River and 15samples from the surrounding oil shales were collected and subjected to petrographic and geochemical analysis. The results showed that the most depletion of main oxides in sediments is related to Na2O and there is enrichment only in relation to CaO. Enrichment of minor elements Sb, As, Ni, V related to shales and Sr is related to the dispersion of clay minerals and lime layers. The depletion of Rb is the consequence of feldspars breaking in process of alteration. Nb, Zr elements are present in sedimentary minerals in minor form. The origin of minor and rare earth elements is related to the place of formation, weathering in the deposits and the amount of total organic carbon in the oil shales scattered in the region. The samples are in the range of litharenite, arkose to shale, which are related to the environments of active continental margin and collisional. According to the Th/U ratio, the sediments were formed from source rocks with the least weathering. The amount of PIA and ICV index of the samples shows the effect of low weathering on sediments related to active tectonic environments.

In this study, the dolomitic part of the Permian deposits in the Qaradagh section, located in the south of Lake Urmia, has been studied and investigated from the perspective of lithology and geochemistry. 92 samples were collected from the 202-meter-thick section. The petrographic studies were conducted by use of polarizing microscope, whereas the geochemical studies were accomplished using AAS method. The petrographic studies were carried out based on textural classification and based on that, two general groups of primary dolomites (at the same time as sedimentation) and secondary dolomites (after sedimentation) were identified. Primary dolomites include dolomicrites (very fine crystals) and secondary dolomites include sparites and dolomites filling holes. The geochemical studies are focused on main elements including Ca and Mg, and rare elements including Fe, Na, Si and Mn. Combining results from lithostratigraphic studies and elemental analysis, the formation environment of the studied dolomites concluded as follow: dolomicrites are deposited in supra-tidal to upper parts and inter-tidal zones, sparites are deposited in a shallow burial environment, and pore-filling dolomites are deposited in a deep burial environment by dolomitic fluids.

Gorgan, a city with a population of about 400,000, experiences a high rate of urban construction and currently produces 1,600 tons of construction waste daily. This waste is managed using two sites: Jorjan 28 for waste accumulation and the Tuskan Road site for landfill. An environmental assessment of the Tuskan Road construction waste landfill site using the checklist method indicates that 84.2% of the parameters related to the landfill site can adversely impact the environment. Studies reveal that the cumulative environmental values, particularly from the physical and biological environmental parameters assessed using the matrix method at the Tuskan Road landfill site, are negative. The fragile ecosystems of northern Iranian cities, limitations on using river sand, mountain quarries, and gravelly agricultural lands, make recycling construction waste essential. Organizing recycling not only reduces negative environmental impacts but also results in significant economic savings by producing recycled sand and gravel.

In order to investigate the biostratigraphic zones and depositional environment of the Pabdeh-Asmari formations boundary, one stratigraphic section (Shirah-Choqachalanchi) has been sampled in the northwest of Ilam. Twenty-five samples were collected from thirty-three meters carbonate layers. All samples have been analyzed for their fossil content and facies characteristics. The Pabdeh Formation in this area consists of thin-bedded limestone with interbedded thin layers of argillaceous limestone, thickening-upward to the Asmari Formation. Fossil studies lead to identification of 13 species belonging to 26 genera of foraminifera that two biozones can be differentiated based on fossil index (Globigerina spp. zone And Lepidocyclina-Operculina-Ditrupa assemblages zone). Rupelian-Chattian age can be proposed for the studied sequences based on biozonation. Facies studies show two facies (1- planktonic and benthic foraminifera wackestone to packstone, and 2- planktonic foraminifera wackestone) related to the outer ramp depositional environment. Facies studies, grain texture and comparing the data obtained from this research with other sections of the region show that sedimentation occurred in a calm outer ramp environment, away from storm wave influence.

The Persian Gulf is the most important aquatic ecosystem in West Asia and the Middle East region. The beach of this Gulf in Bushehr port is one of the most important recreational and commercial beaches in the country. In order to investigate the sedimentology and geochemistry of the Persian Gulf coastline deposits in the area of this port, 28 surface sediment samples were collected and grain size analysis and XRF geochemical analysis was done. The results showed that the sediments of this beach were sand with a small amount of gravel, which indicated continuous energy in this beach and the washing of mud particles. The geochemical results showed that the highest concentration of oxides were SiO2 and Cao. Investigating the source rock and tectonic position of these deposits showed the primary composition of lite arenite and greywacke and the tectonic position of the active continental margin. Hydraulic melting also indicated the immature to medium maturity composition of these sediments, which indicate semi-arid weather conditions with medium chemical maturity. In general, the similarity of the tectonic conditions and ancient climate of these deposits with the Zagros sequence indicated the existence of Zagros as the main source of these deposits.

This study investigates gully expansion and quantifies soil erosion and sedimentation in the Dashte Jeyhoon watershed, Bandar Khamir County. The analysis utilized aerial photographs from 1967 and 1994, historical Google Earth images from 2012, and UAV imagery from 2023 to assess gully growth. Surface erosion was estimated using the WaTEM/SEDEM and RUSLE models. UAV imaging, with a ground sampling distance (GSD) of 3 cm, was conducted to map gully expansion and measure morphometric characteristics, providing an estimate of soil loss due to gully erosion. The findings indicate that the gully area increased from 132.64 hectares in 1967 to 326.39 hectares in 2023, with an expansion rate of 3.46 hectares per year. Detailed measurements were taken at 481 points using a digital elevation model (DEM) with a 6 cm accuracy, derived from UAV data. The average gully depth was found to be 1.01 meters, suggesting that the gullies in the study area are generally small to medium in size. The ratio of top width to depth exceeding 1 highlights significant implications for the destruction of agricultural lands and infrastructure. Flooding and water flow into the gullies were identified as the primary drivers of gully expansion in the watershed. The study estimated that average soil erosion from surface processes was approximately 3.40 tons per hectare per year, while total soil loss from gully erosion was around 52,000 tons per year. Over a 56-year period (1967-2023), the average soil loss due to gully erosion was calculated to be approximately 12 tons per hectare per year. The total annual soil loss from all erosion types in the Dashte Jeyhoon watershed was estimated at 15.4 tons per hectare per year.

The purpose of this research is to investigate the microfacies, sedimentary environment and paleodepth fluctuations of the Gurpi Formation sedimentary basin in southwestern Iran. Lithological and facies studies led to the identification of three microfacies related to the deep parts of a basin. The absence of sedimentary evidences such as calcareous turbidities', slip and fall sediments, reef facies, anchoid and pisoid facies characteristic of the edged shelf indicates the deposition of Gurpi Formation in a deep part of the basin. Based on the ratio of the percentage of planktonic foraminifers to benthic foraminifers and the percentage of morphotype 3 and using the formula D = e (3.58718+ (0.03534 × P%)) for the major parts of the Gurpi Formation in the studied sections, a depth between 450 and 602 meter was introduced, which indicates the sedimentation of the facies of this formation in the deep part of the basin. The abundance of planktonic foraminifera such as Oligosteginid and Globotruncana in the facies of this formation indicates that these sediments were deposited in a deep basin, so that the facies of this environment have characteristics related to the deep shelf facies belt. Examining the paleodepth changes of the Gurpi Formation sedimentary basin based on the morphotypes of planktonic foraminifers in the studied sections, indicates that the Gurpi Formation had a regressive trend, and this trend is consistent with the trend of its sedimentary deposits based on the foraminifera morphotypes. The type where the maximum depth of the basin is during the Late-Middle Campanian and Late Maeistrichtian with the expansion of mudstone to wackestone facies and the lowest depth of the sedimentary basin is related to the Santonian to late Campanian with the expansion of wackestone to packstone facies.

The purpose of this research is to investigate the types of diagenesis processes and the textural changes caused by these processes in the carbonate facies of the Shahbazan Formation in Chenareh anticline section in the south-west of Lorestan. In this section, the Shahbazan Formation with a thickness of 83 meters consists of carbonate and dolomite rocks, which is placed on the Kashkan formation with a discontinuity and is covered by the Asmari formation with an erosional discontinuity. Petrographic studies on 80 sedimentary thin sections led to the identification of several diagenesis processes, including micritization, dissolution, cementation, crystallization, physical and chemical compression, and succession. Among the textural changes in the facies of this formation can be the creation of a thin micrite cover around the allochems, excessive micritization of grains, dense arrangement of grains and creation of fitted fabric, crushing, fracture and crushing. The dissolution of grains, the dissolution of grains and ground rock, cementation limited to grains and widely, types of succession, stylolites and the removal of part of grains and rocks, the formation of stylomottle, reduced neomorphism in the shell of allochems and increase neomorphism, due to the recrystallization of micrite crystals and fractures. Based on petrographic evidence, the paragenetic sequences of Shahbazan Formation have been interpreted in four environments: marine, meteoric water, burial and uplift. Three stage diagenesis have been determined for studied sediments: early diagenesis (eogenesis), middle diagenesis (mesogenesis) and late diagenesis (telogenesis).

The natural bitumen reserves in the Gilan-e-Gharb region are located in the Zagros Folded belt. The study area lies within the tectonic-stratigraphic zones of Lorestan and the Mesopotamia region, and structurally, within the simple fold belt. Elemental analysis conducted on natural bitumen samples was utilized to determine the types of bitumen in the Gilan-e-Gharb region, identify the various type of kerogen, and estimate the approximate reflectance of vitrinite. For these purposes, 8 samples from natural bitumen reserves were subjected to organic geochemical analysis. Natural bitumens with a reservoir origin typically have an H/C ratio of less than 1. Whereas, the analyzed samples have an average ratio of 1.15. Based on this data, the reservoir origin of the natural bitumens in the study area is deemed improbable.Hence a source rock origin for these reserves is plausible. The average carbon content of the samples is approximately 65 Wt%, indicating their high quality. The types of bitumen in the study area include Grahamite (Ptm3), weathered Albertite (Mjm, Ptm1), Glance Pitch (Jv, Ptm2), and low-weathered Gilsonite (Jv). An inverse relationship exists between the percentage of ash and the percentage of volatiles in the natural bitumen samples, as well as between the percentage of ash and the percentage of carbon. As the amount of ash increases, the carbon content decreases, leading to a reduction in the quality of the natural bitumen. A direct relationship is observed between the percentage of volatiles and the carbon content. This means that an increase in volatiles corresponds to an improvement in the quality of natural bitumen (and their carbon content as well). There is an inverse relationship between the carbon content and ash content and hydrogen value. Additionally, an inverse relationship exists between the percentage of volatiles and the oxygen content, while a direct relationship is notable between the percentage of ash and the oxygen content of the samples. A direct relationship is also established between the percentage of volatiles and the hydrogen content of the samples. All samples exhibit a specific gravity greater than one and a negative API degree which is probable due to relatively high sulfur and nitrogen content.

In this research, the facies and marine, coastal and continental depositional environments have been investigated in southern part of the south Caspian Basin (middle part of the Gilan province; Bandar-e Anzali area). In this study, seventy-one surface sediment samples were taken unsystematically from three hundred and twelve recorded points in the shallow areas of the Caspian seabed and surrounding land. Four sediments types, slightly gravelly sandy Mud, slightly gravelly muddy Sand, slightly gravelly Sand and gravelly Sand constitute the largest percentage of all components.Based on X-ray diffraction studies, the sediments are composed of calcite, quartz, feldspar, mica and smectite. The components are classified into two categories: clastic (quartz, feldspar, mica, rock-fragment and clay minerals) and organic-biogenic (plant debris, marine and non-marine organisms (ostracoda, bivalves and Gastropoda)).In general, sedimentation has been done in three areas: land (continental), transition (shore) and marine. The land part composed of the fluvial system (active channel, point bar, flood plain and crevasse splay), coastal plain, wetland, paleo-lagoon, marsh and washover deposits. The transitional and marine parts composed of the shore barrier and the shoreface, respectively. The shore barrier sequence consists of foreshore, backshore and shore dune ridges. Non-marine bioclasts (such as non-marine bivalves Monodancacaspia and Dreissea polymorpha and non-marine gastropods such as Lymnaeidae sp.) in wetland/lagoon, marsh environments and washover deposits and marine bioclasts (such as bivalves Cerastoderma glaucum) has been observed in the washover deposits, shore (shore barrier sequence) and shoreface environments.The sea-level fluctuations (the general trend of the relative sea-level fall along with the short-term fluctuating cycles of sea-level rise and fall), cause the shifting of the facies and shoreline towards the sea (progradation/regression) from the past to the present.