About Quaternary Journal of Iran

  • Country of Publication: Iran
  • Publisher: Iranian Quaternary Association
  • Format: Online
  • Online ISSN: 2476-5635
  • Publisher Code: irqua.2023
  • Frequency: Semannual
  • Publication Dates: Summer and Winter
  • Language: Persion (with English Abstract)
  • Types of Journal: Scholarly Journals
  • Open Access: Yes
  • Policy: Double-blind peer-reviewed
  • Review Time (Submission to Acceptance): 16 Weeks Approximately
  • Alternate e-mail: irqua2014@gmail.com , info@iranquaternary.ir
Plagiarism policy: Although this journal uses different methods and softwares "Hamandjoo" and "Hamyab" to review Persian texts, the main responsibility and all the legal consequences are officially on the corresponding author. 

Open access: Quaternary Journal of Iran is an open access journal which means that all articles are freely available without charge to the user. Users are allowed to read, download, copy, distribute, print, search, or link to the full texts of the articles, or use them, with citing the reference, for any other lawful purpose, without asking prior permission from the publisher or the author. This is in accordance with the BOAI definition of open access. This journal provides immediate open access to its content on the principle that making research freely available to the public supports a greater global exchange of knowledge.

Copyright:  The authors retain the copyright and full publishing rights without restrictions.

All articles sent to Quaternary Journal of Iran should be related to Quaternary sciences and rely on common proxies and methods in Quaternary sciences.

Titles and topics related to the publication:

1) Climatology and Quaternary climate reconstruction.

2) Quaternary climatic events.

3) Quaternary stratigraphy and dating.

4) Neotectonics in Quaternary.

5) Sedimentary environments in the Quaternary.

6) Paleogeomorphology.

7) Quaternary lakes, playas, loess.

8) Dendroclimatology and Dendrochronology

9) Quaternary natural hazards (droughts, sea level changes, ancient earthquakes, ancient landslides, etc.).

10) Historical, prehistoric and Paleolithic archaeology

11) Paleosoil research

12) Quaternary modeling

13) Laboratory methods in quaternary sciences

    https://creativecommons.org/licenses/by-nc/4.0/  

Magmatic Evolution of Volcanic Rocks along Haraz Road: Petrographic and Geochemical Evidence from Plagioclase and Amphibole Minerals

Pages 1-19

https://doi.org/10.22034/irqua.2026.2086702.1064

ramin mazandarani, seyed jamal sheikh zakariaee, seyed mojtaba mortazavi, mansour Vosoughi Abedini, abdollah yazdi

Abstract Abstract Damavand Volcano, as the highest volcano in Iran and the Middle East, is located approximately 50 km northeast of Tehran. The volcanic rocks of the Haraz Road region mainly consist of olivine basalt, trachyandesite, and basaltic trachyandesite, with the primary mineral phases including plagioclase, pyroxene, and olivine. Petrographic studies indicate the presence of textures such as hyalomicrophaneritic, glomeroporphyritic, and vesicular in these rocks. The occurrence of disequilibrium features, including sieve textures in plagioclase, oscillatory and reverse zoning, amphibole opacization, and xenolith fragments, suggests a lack of equilibrium between crystals and melt, indicative of magma evolution in an open thermodynamic system. Examination of these features reveals that magma mixing, together with fractional crystallization, played a key role in the evolution and formation of the region’s volcanic rocks. Lava evolution primarily occurred through crystallization at varying pressures, injection of hot magma with similar composition into magma chambers, and mixing with resident magma. Thermometric calculations of plagioclase indicate that crystallization occurred at pressures of approximately 2.5–18 kbar and temperatures ranging from 750 to 1200 °C. Keywords: Petrography, Plagioclase, Magma Mixing, Central Alborz, Haraz Road, Iran 1. Introduction Damavand Volcano, as the highest Quaternary volcanic edifice in Iran and the Middle East, represents a key location for understanding tectono-magmatic processes in the Central Alborz region. The structural framework of the Central Alborz exhibits a V-shaped configuration, where northwest–southeast trending faults and folds in the western part are separated from northeast–southwest structures in the eastern section. The region remains tectonically active, as indicated by seismicity, GPS-based crustal motion, and geodetic measurements, reflecting an incomplete isostatic equilibrium. This dynamic environment has facilitated magma ascent, influencing the emplacement and evolution of young volcanic products, particularly in Damavand. Volcanic products are predominantly trachyandesitic to trachytic lava flows accompanied by limited but significant pyroclastic and epiclastic deposits, mainly concentrated in the southern and southeastern sectors. Major faults in the area, including Mashaa, Ask, Bayjan, Nova, Sefidab, Shahandasht, and Vararud, play a crucial role in controlling magma migration and vent distribution. Previous geophysical studies estimate the crustal thickness beneath the Central Alborz to range from 35 km (gravity modeling) to 58 ± 2 km (seismic data), with some studies suggesting anomalously thick crust (~65–67 km) beneath Damavand, indicative of a deep magmatic root and complex crustal-mantle interactions. Understanding the petrography and geochemistry of key minerals such as plagioclase and amphibole provides insights into magmatic evolution, crystal fractionation, magma mixing, and thermodynamic conditions during crystallization. 2. Materials and Methods A total of 70 representative volcanic rock samples were systematically collected along the Haraz Road region. Thin sections were prepared from all samples and examined using a polarizing microscope to assess mineralogical composition, textures, and microstructures. The primary focus was on plagioclase and amphibole crystals, evaluating their zoning patterns, reaction rims, dissolution features, and textural relationships. Petrographic criteria for magma mixing, including oscillatory zoning, sieve textures, and xenocrystic inclusions, were identified. Amphiboles were studied for reaction rims, opacization, and evidence of chemical disequilibrium. Geochemical analyses were conducted to quantify major and trace elements, while thermobarometric calculations estimated crystallization temperatures and pressures of plagioclase and amphibole phases. Crystal size distribution (CSD) techniques were applied to quantify crystal populations and to interpret magmatic processes such as fractional crystallization, magma mixing, and multi-stage crystallization events. 3. Results and Discussion Petrographic observations indicate three dominant volcanic rock types: trachyandesitic-basaltic lavas, trachyandesites, and olivine basalts. Trachyandesitic-basaltic samples exhibit porphyritic to microlitic textures with plagioclase ranging from labradorite to anorthite, commonly displaying oscillatory and normal/reverse zoning. Alkali feldspars are generally sanidine with variable crystal shapes. Pyroxenes are mainly augite, occasionally showing twinning, and amphiboles display partial to severe alteration, including opacized margins. Olivine basalts show porphyritic and microlitic textures with olivine, augite, and minor plagioclase phenocrysts; mafic phases often partially replaced by opaque minerals. Textural evidence such as sieve textures, zoned plagioclase cores and rims, and reaction rims on amphiboles support the occurrence of open-system magma processes, including repeated injections of hotter, more mafic magma into evolving magma chambers. Oscillatory zoning in plagioclase is attributed to variations in pressure, temperature, water content, and diffusion kinetics within the magma chamber. Sieve textures and dissolution features in plagioclase and olivine indicate magma mixing and transient disequilibrium during crystallization. Amphibole breakdown, formation of reaction rims, and opacization reflect sensitivity to temperature, pressure, and volatile content, consistent with observations in analogous volcanic systems. Thermobarometric results suggest plagioclase crystallization occurred at pressures of ~2.5–18 kbar and temperatures of ~750–1200 °C. CSD analyses reveal crystal population heterogeneity, confirming fractional crystallization, magma mixing, and polyphase growth events. The combined petrographic, textural, and geochemical evidence indicates that magma mixing and partial crystallization played critical roles in the evolution of Haraz Road volcanic rocks. 4. Conclusion The volcanic rocks of Haraz Road, Central Alborz, record complex magmatic processes characterized by magma mixing, oscillatory zoning in plagioclase, dissolution features, and amphibole reaction rims. The interplay between repeated injections of hotter mafic magma, fractional crystallization, and variations in pressure, temperature, and water content controlled mineral textures and chemical compositions. Thermobarometric results confirm crystallization of plagioclase at 2.5–18 kbar and 750–1200 °C, consistent with open-system magmatic evolution. Crystal size distribution analyses support the occurrence of polyphase growth, magma mixing, and fractional crystallization. Collectively, petrographic and geochemical evidence highlights the dynamic magmatic environment of the Central Alborz and provides insights into crustal processes controlling volcanic activity in Damavand.

Natural hazards (paleoseismology, landslides, ..)

Investigation of hydro-geochemical quality of surface water for drinking water use (Case study: Qalikuh region, Lorestan province, southwest of Iran)

Volume 7, 1, 2, September 2021, Pages 39-57

https://doi.org/10.22034/irqua.2021.702415

Amir Saeed Hosseini, Saeed Hakimi Asyabar, Mozhgan Salvati

Abstract Introduction
Rivers are one of the most important water resources and it is very important to study their water quality. Therefore, in this study, sampling was done from 15 permanent waterway stations of Pirbadush and Gashun of Qolyan River in Lorestan province, which are located in the path of oil shales.
 
Materials and Methods
 Hydro-geochemical parameters were calculated by analyzing the samples in the laboratory. Then compared with drinking water quality assessment standards in the region and Hydro-geochemical diagrams were also drawn.
Discussion and Results: Qolyan River water contains a lot of calcium carbonate and only sample P3 has more magnesium carbonate that it is unsuitable for drinking due to its high calcium content, but it is suitable based on other parameters.
 
Results
According to Schoeller quality classification, Gashun samples are of lower quality than Pirbadush and by the standards, most samples are within the allowable-favorable range and water of G6, G7, P5 stations have lower quality than other stations. According to the WHO table, the water of the Qolyan River is relatively light in terms of TH and total dissolved solids (TDS) and relatively light in terms of Electrical conductivity (Ec). Based on hydro-chemical tests and data analysis and hardness estimation and comparison with the national standard of Iran and the standard of the World Health Organization, the results of water classification of the samples are as follows: According to the World Health Organization's calcium ion (Ca2 +) content, water samples from G7 and P5 stations are impermissible and based on the total hardness of the Iranian national standard, the water samples of stations P1 and P3 are in the favorable level.
According to hydro-geochemical diagrams, the water quality of Pirbadush waterway is better than Gashun. According to the Piper diagram, In Gashun samples, the tendency of the samples towards magnesium and sulfatation is more than the samples of Pirbadush region. According to the Durov diagram, most of the water samples taken from Gashun and Pirbadush waterways are calcium carbonate (Ca-CO3) and calcium bicarbonate (Ca-HCO3). According to Schoeller diagram, the amount of tumble in the samples of Gashun waterway is more than Pirbadush waterway. According to the ion equilibrium diagram, the amplitude of change of anions and cations in Gashun waterway is more than Pirbadush. According to Stiff diagram, the different origins of the samples indicate the existence of several bedrock sources for the samples, and according to the Gibbs diagram, bedrock and weathering and dissolution are the main factors controlling the water chemistry of the region.
By examining the water quality of Qolyan River in Pirbadush and Gashun waterways with any human activity that it is in the path of oil shales, the results were obtained which are:
-The highest amount of cations and carbonate anion (CO32-), is in G7 station and the highest amount of nitrate anion (NO3-), are in G6 and P7 stations.
-The highest water total hardness (TH) is related to stations G7, G6, P5 and the lowest is related to stations P3, P1, G1.
-The highest total dissolved solids (TDS) in water is related to stations G6, G5,  G7 and the lowest amount is related to P1, P4, P3.
- The presence of higher amount of calcium carbonate (Ca-HCO3) in Gashun waterway than Pirbadush indicates a higher degree of solubility of calc than dolomite in this section.
- High sulfate content in Gashun waterway (especially G1 station) can be related with further dissolution of anhydrites in the Gotnia Formation.
-Anion and cation equilibrium also shows that ionic equilibrium is present only at stations G3, G5, P6. However, at stations P1 and P3, there is a high degree of ionic imbalance between anions and cations.
 
Conclusion
 In this area, the type of rock units and even the presence of oil shales have not had a detrimental effect on the quality of drinking water.

Sedimentary environments, paleogeomorphology

Assessment of active tectonics based on geomorphological and morpho-tectonic analysis of the basin (case study: Qeshm Island)

Volume 9, 1,2, September 2023, Pages 213-238

https://doi.org/10.22034/irqua.2023.709905

Adel Rasooli, Mehran Maghsoudi, Aboulghasem Gorabi

Abstract Qeshm Island, with an area of ​​1,486 square kilometers, is located at the southeastern end of the Zagros Belt and at the western end of the Strait of Hormuz. Since the tectonic era, it seems possible to assess the influence of neotectonics and fault dynamics on island morpho-tectonic deformation using basin tectonic indicators. In this research, five indicators are extracted and calculated using satellite images, geological maps, aerial photographs, and a digital elevation model (30 meters) using various software. The smoothness and asymmetry of waterways (AF), watershed shape index (BS), cross-topographic symmetry index (T), river meandering index (S) and their comprehensive evaluation are evaluated in model form (IAT)). It is an index to evaluate the degree of tectonic deformation in the basin, and the obtained results indicate the relative dynamics of various tectonic deformations on the island. Furthermore, based on the IAT index, 26 of the 44 subbasins belong to a very high tectonic layer, consistent with the number of faults, so more active tectonic deformation is observed in the western part of the island.

Quaternary archaeology

Techno-typological Analysis of Qaleh Kurd Cave Lithic Industries, Aavaj, Qazvin

Volume 8, 3,4, February 2023, Pages 262-288

https://doi.org/10.22034/irqua.2023.705430

Zahra Kamrani, Hamed Vahdati Nasab, Stephanie Bonilauri, Seyyed Milad Hashemi Sarvandi, Mozhgan Jayez, Mohammad Akhavan Kharrazian, Seyyed Iraj Beheshti, Gilles Berillon

Abstract Introduction
Qaleh Kurd cave is located in the village of the same name in the vicinity of Hesar Valiasr village, Avaj city, Qazvin province. This cave is located on the route between Zagros and Iranian Central Plateau and along one of the proposed corridors of scattered human groups in the Iranian Plateau (Vahdati Nasab et al., 2013; Dennell, 2020; Shoaee et al., 2021). The first archaeological study in the cave was conducted in 2013, in which a small surface collection of 35 stone tools on the surface was studied and attributed to the Middle Paleolithic era (Soleimani and Ali Beigi, 2018).
With the initial investigation of the walls of the pits caused by unauthorized excavations and the presence of cultural materials and animal remains in the cave, the first idea about the possibility of exploring this area was formed. The first examination in Qaleh Kurd cave was conducted in 2017 by some of the authors (HVN & GB). Consequently, the joint Iran-France mission under the supervision of (Vahdati Nasab, Berillon and Hashemi) conducted three archaeological field mission in there (2018, 2019, 2022). It is worth mentioning that here we only present data collected during the first two seasons.
Some of the major goals of conducting field missions in Qaleh Kurd are: Investigating the Paleolithic deposits, how the site was formed, comparing lithic industries with other Middle Paleolithic sites of Iran, reconstructing the diet of cave dwellers and trying to obtain human remains. The purpose of this article is to describe the techno-typological aspects of lithic collections recovered from 2018 and 2019 missions and to compare it with the lithic industries of Zagros, and the sites from the Iranian Central Plateau.
Materials and Method
The stratigraphy of the trench 1 wall indicates the existence of two distinct sequences, Holocene and Pleistocene, and the identification of 25 stratigraphic units (1 to 9 related to the Holocene and 10 to 25 related to the Pleistocene). The preliminary results of dating samples taken from 30 cm from the beginning of the Pleistocene layer in Trench 1 indicate an age beyond the range of carbon-14 dating (43,500 years ago). Therefore, in the continuation of the research, the ESR method was used for the dating of cultural materials (especially animal teeth). It is worth mentioning that at the time of writing this article, the above-mentioned chronology is being finalized and the preliminary results indicate an age of more than 300.000 BP for the Pleistocene deposits, which will soon be published in separate research.
The subject of the present research includes the stone artifacts obtained from the exploration of the first and second seasons. In total, 1257 stone artifacts were obtained from excavations in trenches 1 and 3. In this study, the data obtained from Trench 1, the largest explored trench, is presented. The excavation dimensions in trench 1 were 1.2966 square meters in the first season and 6.195 square meters in the second season.
Quantitative characteristics, typological information and technology of tools have been recorded and studied. In a general classification, stone artifacts include tools, debitage, core and core fragments, and debris. According to the stratigraphic information of trench 1, the Pleistocene sequence of Qaleh Kurd is divided into fifteen sedimentological units and five successive archaeological subdivisions. The division of archaeological periods is based on sedimentological studies, changes in the density of stone artifacts and animal remains, and data distribution in depth.
The first period or the late period (QK 1) starts from about -50 to -80 cm (Z) of trench 1 and includes sedimentological units 12 and 11. Unit 11 in the eastern wall of Trench 1 consists of gravelly sand silt with pebbles and flat unlayered gravels with charcoal remains. Unit 12 also includes sandy silt with a number of calcite gravels, a matrix with low compression and more compactness. QK 2, or the middle period, starts from the depth of -80 and continues to the depth of -105. This course is in line with unit 13. This unit in the south wall of Trench 1 has a light brown color and debris pieces and quiet dynamics. Unit 13 on the eastern wall of Trench 1 has sand-silt with many pebbles and flat calcite debris. QK 3 starts from the depth of -105 and continues to the depth of -130. This course includes units 14, 15 and 16. Unit 14 in the south wall of Trench 1 consists of clayey silt with gravel and is brown in color. Unit 15 includes organic silt and unit 16 includes silt (clay). In Unit 16, we see gravel, calcite nodules and ancient soil. On the eastern wall of Trench 1, silt with gravel in unit 14 and silt with organic clay in units 15 and 16 are evident.
The raw materials of Qaleh Kurd stone artifacts are diverse, including limestone rich in silica, jasper, chert group, volcanic stones such as basalt, a limited number of marbles, radiolarite, clay and quartzite. The most used raw materials in all the phases of Qaleh Kurd are siliceous stones rich in lime, so that in the first period 22.5%, in the second period 20.5% and in the third period 32.1% of artifacts are built on limestone.
 
Conclusions
In Qaleh Kurd lithic complex, the cores are very limited and it seems that the initial steps of chipping were done outside the area. A variety of raw materials have been used in this collection, and the three aforementioned Qaleh Kurd periods show different abundances in the use of raw materials. In this area, sidescrapers are the most abundant type of tools, after that we are faced with a significant abundance of points and convergent scrapers. The studies conducted on the quantitative characteristics, typological and technological indicators of the stone artifacts showed that in terms of dimensions and quantitative characteristics, the lithics of the first, second and third periods of the cave demonstrate no difference, but the dimensions of the blades are somewhat different from each other. The comparison of the abundance of raw materials, extractions, platform typologies, and Levallois technique between the periods shows the difference of the third period from other periods to some extent. In this period, we see a high accumulation of lithics compared to other periods, this can be due to the intensity of settlement in this period of the site.
The results of the comparison of Qaleh Kurd stone artifacts with other Middle Paleolithic sites show that Qaleh Kurd cave in the extent of using the Levallois technique, the abundance of scrapers, especially sidescrapers, the abundance of points, especially the Mousterian points, the faint presence of notch/denticulates and, the intensity of retouching and the abundance of flaked base debitages show a closer proximity to the Zagros sites.

Climate change, climate events

Holocene Vegetation and Climate Changes in Iran

Volume 3, Issue 3, Autumn 2017, Pages 205-229

https://doi.org/10.22034/irqua.2017.701911

Ghasem Azizi, Sahar Maleki, Mostafa Karimi, Reza Shahbazi, Homa Rostami

Abstract Vegetation is very sensitive to climate change and is an important factor for identifying the changes of climate and environment. In 12000 to 6000 years ago there was extreme climatic conditions in the southwest Asia with hotter and longer summers than the current conditions. As a result of such climatic conditions, many shallow lakes and seasonal rivers have been disappeared and vegetation altered. Plants that were more adapted to environmental conditions and dry seasons like annual plants includes (peas, lentils, wheat ) by the  changes in legume and shape of the grain, completed their annual life cycle. Studies have shown that the climate has changed between cold and dry conditions during glacial and hot and humid periods in interglacial in north and west of Iran. The lake sediments and paleo sol layers in loess deposits indicate there was an increase humidity during period between the last interglacial and pre end glacial period (Kehl, 2009). The Palynological results of paleo ecological sites in west of Iran have shown that there were steppes of Artemisia and chenopodiaceaes in glacial periods that represent cold and dry climate in this region. About 6500 years ago, Zagros oak forests have replaced by pistachio-oak vegetation. Studies in parts of Iran such as Zaribar Lake, Urmia Lake, Mirabad Lake and comparison with the Van Lake in Turkey showed that they have almost the same vegetation changes. In all of these studies, the end of the Yongerdryas and the beginning of the Holocene by a sudden increasing in chenopodiaceae vegetation (which represents cold and dry weather) and gramineaes ( which represents warm and dry weather) are characterized (Davoodi et al,2014). Generally, the global climate cycles and events in different parts of the Iran are rarely studied and our understanding of paleo climate and paleo ecological conditions is very insignificant. Pollen data from lakes or tree rings data have the potential for identify the paleoecology conditions in Iran.
Result and Discussion:
Climate and vegetation changes in Iran in Holocene:
Palynological studies in Komishan wetland (located on the southeastern part of Caspian Sea) has provided significant results about vegetation changes and sea level fluctuations. Delay in forest growth at beginning of the Holocene, which is in areas of eastern Turkey, there was also on the plateau of Iran and the south of the Caspian sea and in the northeastern slopes of the Alborz mountain (Gomishan). Pollynological studies and radiocarbon dating in Neur lake showed about 12800 years ago, in the late glacial ratio of trees pollens has been negligible,in the transition to the early Holocene pollens of trees and shrub vegetation such as Ephedra gradually increased. During Younger Deryas in Neur,the grasslands replaced with trees.In early Holocene at 9800 years ago Artemisia increased in Neur because it seems that there was a more milder phase in the north of Iran.  An increase in Oak and herbaceous palnts pollens such as artemisia showed that between 8000 and 9000 years ago there was wet phase in the  Neur basin. The presence of  high  amounts Alnus  pollen in the north of Iran  has shown that there were humid climate in the northern parts of Iran at 3000 years ago. Evidences suggests that highest levels of Caspian sea occurred between 1900 and 2100 years ago.

vegetation and climate in Holocene in the west of Iran

In the west of Iran during the 40000 to 20000 years ago, there was scattered vegetation (shrubs and trees). In late Pleistocene (22000 to 14000 years ago) there was arid and semi arid steppes in this region. In interglacial period in Holocene (10000-6000 years ago) precipitation increased Gramineae replaced with chenopodiaceae and Almond and Pistacia atlantica grew up such a change in vegetation indicates an increase in precipitation.In the Zagros mountain 7000 years ago Pistachio trees have existed which represent dry climate in early Holocene in this area. In mid Holocene moisture increased and vegetation was changed to Oak-Pistachio forests.In the early Holocene in western regions of Iran winter rainfall has increased and have been dry conditions in summers,In 6000 years ago in mid Holocene there was warm and humid climate in this region and Oak forests expanded. In the west of Iran, Almond and pistachio forests were more than Oaks, it indicated that humidity in spring and summer was more than other seasons in early Holocene. 
In the Last glacial  Period The Ephedraceae shrub steppes has been developed(Djamali et ak,2008).In middle of the last glacial period the water level of Lake Urmia increased, In transition between last glacial to Holocene in the west of Iran, dominant plants were ephedraceae,pistachio,Oak, Juniperus excels and Betula alba.Untill 9000 years ago dominant plants in Urmia basin was Artemisia steppes,In this basin, forests has been developed between 8000-9000 years ago.The results of Studies showed that Pollens in the west of Iran decreased in 2500 to 1500 years ago and replaced with Artemisia pollens (Talebi et al,2015). In Late Holocene Pollens such as Oak pollens has icreased (1600-1200 years ago) and there was a humid climate in the west of Iran.Also the level of Urmia lake was higher than present and the water salinity was lower.Presence of Reilla spores and low magnetic sensivity and calcium carbonate values confirmed this fact. in 1200 to 900 years ago water level in  Urmia lake decreased,  on the edges of lake ,Halophytes increased. The semi desert steppe developed in area. Pollen of Artemisia and Chenopodiaceae, Senecio vulgaris, chamomile and  Acantholimon has increased that indicate the dry and cold climate. At 650 to 450 years ago lavel of lake increased. Pollens of Juniperus represents a cold and dry climate in this region.
In the late Pleistocene and Younger Deryas period, the south Zagros had a Cold climate with steppe vegetation(Davoodi et al,2014). Davoodi et al(2014) concluded that bigining of Holocene in Parishan lake was about 10200 years ago and lasted to 8170 years ago. In this period Artemisia and Chenopodiaceae have decreased and Geraminea have increased. So we can concluded that the humidity in spring and Summer have increased but it was not enough to grow Oak trees, of course Almond and Pistachio trees grew well. Precipitation required for the growth of almond and pistachio forests is about 300 mm but for Oak forest it is 500 mm.Evidences indicated that climate in early Holocene in the southern Zagros Mountains was dry and hot. In 8170 to 7570 years ago Gramineae vegetation decreased    around Parishan Lake and cold resistant plants such as Cousinia, Umbelliferae and Cichorioideae plants has increased (والتر،1971). In this period dry climate has dominated and summer precipitation has decreased. In 7570 to 5600 yaers ago Oak forests expanded also Almond trees and Asparagus trees increased around the southern Zagros.in this period humid climate has dominated.  In western and southern parts of Iran, In 5600 to 2700 years ago Climate was warm and humid.
North west-West of Iran
The vegetation and climate of southern and southeast of Iran  in Holocene:
Distribution of grain size,petrographic characteristics and sedimentary cores chemical measurements show that:

There was a  full of water lake in Sistan basin, in the late glacial to Early Holocene. MLW(Mid Latitude Westerly currents) and ISM (Indian Monsoons) precipitations has fed the area.
In Early Holocene to Mid Holocene  ITCZ  moved to  the south so ISM weakened, as a result, dry periods started in Sistan basin. High pressure gradient between Sistan depression and Hindu Kush Mountains caused severe and persistent dust storms.
In mid Holocene to late Holocene hydroclimate regime in Sistan basin has controlled by MLW precipitations. The frequent fluctuations iin the water level of Lake Hamoon represent the unsustainable climate  in early Holocene to mid Holocene.
There are not enough information about pollens in the south-southeast of Iran and we can only reconstruct vegetation 1900 years ago. Results show that 910 years ago in this region plains turned into deserts.
Climatic anomalies in Medieval in 1145-910 years ago xerophytes grew in south and southeast of Iran. Impagidinium paradoxum in gulf of Oman Indicated the absence of ocean water drainage.

 By using pollen data and sedimental cores Miller et al (2016) reconstructed vegetation in south of Iran and reconstructed vegetation areas:
The overall dominance of Poaceae, at the expense of Amaranthaceae and Asteraceae and the decrease in clay abundance throughout the LIA suggests a shift from desert to grassland vegetation, implying wetter conditions during the LIA in S Iran. Modern ecoregions within close proximity to the coring locality where grass is a dominant component of the vegetation composition include the Zagros Mountain Forest Steppe and the Baluchistan Xeric Woodlands, where annual precipitation exceeds more than 150 mm per year, Additionally, the abundance of I. paradoxum and Dubridinium sp. is low suggesting an increased amount of freshwater discharge into the ocean. The high abundance of S. ramosus a species particularly observed where the upper water salinity conditions are reduced permanently, again suggests more freshwater discharge into the ocean near the coring vicinity. The low pollen to dinocyst (PD) ratio values during the LIA indicates more marine organic flux, likely due to increased nutrient supply promoting an increase in dinocyst populations. A decrease in Betula and a slight increase in Amaranthaceae abundance are evidenced during the last c. 100 years, which may
 
Conclusion:
Climatological and vegetative evidences suggests that cold periods in Iran have been accompanied with increase in air aridity. Probably in cold and dry periods Siberian anticyclone was strengthened and led to weakening and southward shift of monsoons. Perhaps at that time cyclones of westerlies were also weakened. In northern Iran prevailing winds were from north or northeast, have originated from central Asian deserts. Evidence of these winds are Quraqom desert sand dunes and the spatial distribution of loess deposition in Kopet Dag and north of Iran. During the glacial periods direction of prevailing winds have been northwest to northeast for tropical currents (Kehl, 2009). In the Quaternary period in Iran climate has changed several times, glacial periods has dry and cold climate than now, also many of studies concentrates on west and north parts of Iran and there is no enough data and information for the east and central parts

Neotectonics and faults

An analysis of environmental evolution in the area of Qalae Bon, Babol city, Mazandaran province

Volume 7, 3,4, March 2022, Pages 340-369

https://doi.org/10.22034/irqua.2022.702439

Mojtaba Safari, Hamid Nazari, Hassan Fazli Neshli, Elaheh Rahimi, Mina Madihi, Hassan Afshari, Narjes Heydari

Abstract The environment has had a significant impact on prehistoric human life, he chose the right place to live according to the potential of the environment. Humans were not yet aware of the technological advances for serious environmental change, and one of the most important reasons for choosing a habitat was access to fresh water. This important factor for selection, in some cases, led to dissolution. Consecutive droughts have led to habitat abandonment and settlement collapse, and in other cases, some settlements have been completely abandoned or have a cultural break due to changes in river direction and floods. Qala-bon area is one of the areas that has been culturally interrupted due to flood sediments. A culture with a thickness of about one meter was identified, which indicates a break in this area...

Climate change, climate events

Investigating the history of the establishment and evolution of Sirik mangrove and its relationship to climate change and relative sea level

Volume 9, 3, 4, October 2023, Pages 383-402

https://doi.org/10.22034/irqua.2024.2029265.1026

Mohammad Ali Hamzeh, Mehrshad Taheri

Abstract Introduction

Mangrove forests are dynamic coastal environments where climatic conditions and water levels lead to diverse chemical, physical and biological environmental changes in different time frames, which are recorded in their sediments. In this study, physicochemical (grain size, magnetic susceptibility, total organic carbon, colour, bulk density and porosity) and biological (diversity and abundance of benthic foraminifera) data from a radiocarbon-dated sedimentary core from Azini Creek were used to reconstruct palaeoenvironmental and the relative sea level change in Sirik mangrove during the last 2700 years.



Materials and Methods

The estuaries of the Sirik region are located between 26°15' to 26°25' N and 57°4' to 57°8' E with an area of 3500 km2 in Hormozgan province, at the boundary between the Oman Sea and the Strait of Hormuz. This area is the only estuary with two mangrove trees containing Avicennia marina (Hara) and Rhizophora mucronata (Chandal). Core Az (1.5 m long) was collected within the mangrove of the Azini Creek, using a 7 cm diameter Russian peat sampler. Physiochemical and biological analysis of sediments (magnetic susceptibility, grain size, total organic carbon %, colour, porosity bulk density and foraminiferal assemblage) were performed. One radiocarbon age was determined in the Poznan laboratory by the AMS radiocarbon method.



Results and discussion

The radiocarbon age of depth 144-146 cm shows that the base of the core ages about 2700 cal. yr BP. Based on physiochemical and biological parameters the core Az was subdivided into five units of A-E. In core Az, a total of 66 foraminifera species were identified, encompassing 24 genera and 20 families. Among these species, 44 are characterized by hyaline tests, 20 by porcelaneous tests, and 9 by agglutinated tests. Sediments of core AZ are not very diverse and are all composed of sandy silt and sandy mud. Unit A is composed of olive green (5Y-5/2) sandy silt with the highest magnetic susceptibility (6.3×10-5 SI) and foraminiferal diversity (mean 17 species in 10 cm3) belonging to three groups (shallow marine environment). In unit B, sand content decreases by 50% and sediments turn to sandy mud. In this unit frequency and diversity of foraminifera decrease and porcelaneous taxa disappear (playa-lagoon). In unit C sand content (mean: 38%) and frequency of foraminifera increases again (4600). This unit represents a low mangrove adjacent to the tidal channel. In units D and E sand content decreases gradually and organic carbon and plant remains increase dramatically. Concurrence of agglutinate and opportunistic hyaline taxa suggest the provenance of mangroves in the area.

The results showed that from 2700 to 1800 years ago, the relative sea level was about 1m higher than that of today and fluvial input to the area was higher than the present. At the end of this period, the decreasing trend in the relative sea level and humidity caused the relatively humid marginal coastal environment to become a shallow playa environment. From 1400 to 1800 years ago, stabilizing the relative sea level led to the expansion of tidal channels, which provided a suitable environment for the initiation of mangroves. At this time, the gradual decrease in temperature caused a relative increase in Mediterranean winter precipitation. This climatic optimum period is traceable in other parts of the Iranian Plateau and the Near East. During the last 1400 years, the development of the mangroves began in the region. This mangrove evolution matches to the mangrove growth in the Gowatr (SE extreme of Iran) and Khuran (west of Hormuz Strait). This period coincides with the relative dryness with high climatic fluctuations. In this period gradual increase in winter temperature caused the northward migration of winter westerlies and therefore reduction in winter precipitation. This climatic deterioration is observed in other parts of the Iranian Plateau.



Conclusion

With an age of about 4000 years, the Gowatr mangrove is the oldest in Iran. 2500 years later, mangroves entered the Strait of Hormoz in Sirik and Khuran. During the last 3000 years changes in the earth's orbit around the sun caused the mean annual sea surface temperature in the Oman Sea and the Persian Gulf has increase between 2-3 degrees Celsius, which is the result of an increase in the average winter air temperature. This study shows that during warmer periods, the northward movement of winter westerly winds causes a decrease in winter precipitation in the area.





Keywords: Azini, Mediterranean winter precipitation, Chandal, Harra, Foraminifera



Acknowledgements

This investigation evolved from a research project entitled: "The history of appearance and evolution of Iranian mangroves since the Mid-Holocene and its link to the climate and sea level change", being supported by a grant from the Iran National Science Foundation (INSF) (No. 99017678).

Stratigraphy and Dating

Chemistry of mafic minerals and thermobarometry of Bazman Quaternary volcanic rocks

Volume 5, Issue 2, Summer 2019, Pages 205-220

https://doi.org/10.22034/irqua.2019.702279

Keyvan Shiites, Rahim Dabiri

Abstract Abstract
1-Introduction
Bazman volcano is located on Chgay - Makran magmatic arc. This magmatic arc with east-west trend is 500 km long and 150 km wide and extends from southeastern Iran to southwestern Pakistan. Early evolution of the Makran zone from the upper Oligocene to the upper Miocene is characterized by turbidite sediments deposited on the oceanic crust. There are several quaternary volcanoes such as Bazman, Taftan, Shahsavaran and Soltan (southern Pakistan) which situated along northward of Makran subduction zone as continental arc magmatism. Bazman volcano as an astratovolcano have been explosive and non-explosive eruptions in Quaternary. The purpose of this paper is to investigation of mafic minerals chemistry and thermobarometry of Bazman Quaternary volcanic rocks.
 
2-Materials and Methods
Based on field studies, its volcanic rocks are classified into two groups Quaternary and Neogene volcanic rocks. Petrographic studies were conducted with the preparation of thin sections of rock and were named rocks. Three samples Quaternary units (Qa1, Qa2, Qa3) were selected for microprobe analysis.  Mineral analyses were conducted at Iran Minerals Processing Research Center Electron Microprobe Laboratory using a Cameca SX100 electron probe microanalyzer outfitted with combined WDS and EDS systems. The analyses were conducted at an accelerating voltage of 15 kV and a beam current of 10 nA.
 
3-Results and discussion
 According to Petrographic studies, unit Qa1 was formed of  andesite, andesitic basalt, basaltic andesite and andesite lithic crystal tuff, unit Qa2, andesite to trachyte andesite and basaltic andesite, unit Qa3,andesitic basalt, olivine basalt and basaltic andesite. 3 sample basaltic andesite and olivine basalt Quaternary units were selected for mafic mineral microprobe analysis. Olivine phenocrysts of olivine basalt are chrysolite mineral. Clinopyroxenes are augite and orthopryoxene are clinoenstatite. Amphibole minerals are hornblende, magnesio-hornblende, hastingsite hornblende, tschermakite hornblende and tschermakite. Pyroxene composition in igneous rock depends on the chemical composition and tectonic setting of the host lava which can be used widely to determine the series of magmatic and physicochemical conditions such as pressure, temperature, oxygen fugacity. Ca+Na vs Ti diagram define that the pyroxenes occur in the range of tholeiitic calc-alkaline. Al2O3 vs TiO2 diagram was drawn to identify the nature of magma. This diagram  shows orthopyroxene of both the Quaternary units and clinopyroxene unit Qa1 calc-alkaline ranges and clinopyroxene unit Qa2 tholeiitic tendency. The chemical composition of the samples pyroxenes evaluates the physicochemical conditions of magma such as pressure, temperature, oxygen fugacity.Using Al IV + Na vs Al IV + 2Ti + Cr diagram which depend on the amount of 3-valent iron in pyroxenes, we can get oxygen fugacity. The diagram is set based on the aluminum balance in the tetrahedral position and Cr3+in the octahedral position. The Fe3+ in pyroxenes can be displaced 3-valence elements such as AlVI, Ti and Cr in the octahedral position. In the other hand, Fe3+in pyroxenes depends on the amount of AlVI which means that it depends on the aluminum balance in tetrahedral and octahedral position. The pyroxenes which crystallized at high oxygen fugacity, has been situated above the line of Fe3+. Furthermore, Papike and Cameron (1976) have mentioned the distances of the samples from the Fe3+ line and noted that further distances of the samples from this line were indicating more oxygen frugalities in their geological setting. In this diagram samples are located above the line of Fe3+. In order to study thermodynamic conditions pyroxene crystallization is used methods Soesoo (1997) and Patrikia (2008). By Soesoo (1997)  clinopyroxene samples operating temperature range 1200c°-1300c° and comprised approximately at 1250 c°. Orthopyroxene samples are composed at temperatures from 1150c°-1200 c°. Accordingly, the pressure range of clinopyroxenes is 6-10 kbar and Orthopyroxenes 2-5 kbar. By Patrkia (2008) orthopyroxenes crystallization temperature  Qa1 unit is 1124c° and clinopyroxene and  1145c°  and the setting pressure at the orthopyroxene is 5 Kbar and clinopyroxene 8 Kbar. Orthopyroxenes crystallization temperature  Qa2 unit is 1068 c° and clinopyroxene and  1100 c°  and the setting pressure at the orthopyroxene is 2.2 Kbar and clinopyroxene 4.3 Kbar. According to both methods clinopyroxene crystallization, temperature is higher than orthopyroxene in  Quaternary units. Temperature and pressure of the magmatic Qa1 little more than Qa2. Reduce pressure and temperature conditions of crystallization orthopyroxene can be attributed to an increase in the amount of iron in the crystal lattice orthopyroxene. The temperature and pressure determined on the basis of the mineral olivine  in olivine basalt rock (Qa3 unit) are about 1100 °C and 5.5 Kbar.
 
4-Conclusion
3 sample Quaternary units were selected for microprobe analysis. According to the pyroxenes chemical composition in basaltic andesite rock, orthopyroxene of both the Quaternary units and clinopyroxene unit Qa1 are calc-alkaline ranges and clinopyroxene unit Qa2 is tholeiitic tendency. The pyroxenes which crystallized at high oxygen fugacity. Clinopyroxene crystallization temperature is higher than orthopyroxene in  Quaternary units. Temperature and pressure of the magmatic Qa1 little more than Qa2. Reduce pressure and temperature conditions of crystallization orthopyroxene can be attributed to an increase in the amount of iron in the crystal lattice orthopyroxene. It could be related to tholeiite conditions magma before crustal contamination. The average pressure and temperature of the Quaternary magma chamber based on mafic minerals can be estimated at 1141 °C and 5.5 Kbar.

Keywords Cloud