داریوش مهرشاهی

In the cultural history of several past civilizations, caravanserais have played a decisive role in economic, social, cultural, political and defense-security history. Thus, caravanserais not only served as a resting place and refuge for travelers, merchants and caravans, but also played an important role in the economy and trade and the distribution of products and incomes in various regions. They also served as temporary residences for people from different lands and ethnicities, and thus a place for cultural interactions and the exchange of ideas and customs between them. In addition, they were places for disseminating and exchanging political and economic news between different regions of a country.The present article examines the existing records of a cultural heritage left over from the Safavid era, namely the Caravanserai of Nodoshan Rabbit Castle. For this purpose, by studying documents, and using a descriptive-analytical approach, research questions are examined in three areas: history and historical documents of the caravanserai, how and why the castle building was destroyed, and the spatial assignment of the castle building. The main message of this article emphasizes the need to pay attention to the restoration and revival of this work by giving it a new use so that it can better and more effectively recognize the precious heritage of our past history to the present and future generation.

The sand ramp (or Kouh Rig as in Farsi) is a phenomenon formed by accumulation of sand and other materials in the upwind side or leeside of a mountain slope. This formation is due to the multiple interactions of extreme wind actions, feeding and displacement of sand, physical obstacles, and slope-induced processes. Unfortunately, the phenomenon is not well-known in the physical geography studies of Iran. The sand ramp, about five km west of Taft city, was selected to be investigated due to its relative intactness. Some sand samples were extracted from the depth of 0.4m and 4.2m on the top of the sand ramp. The samples were cleaned several times to provide pure quartz particles that were then analysed using the Optically Stimulated Luminescence (OSL) dating method. The results of dating indicated that the top half section of Farashâh sand ramp was probably accumulated during or near the last glacial maximum phase (something between 18000 to 24000 years ago). The results also emphasize that, in contrast to the theory of cold and wet conditions, with more rain during the glacial phases of Quaternary on the Iranian plateau, at least for parts of the glacial (cold) phases, colder and drier environments with very active winds were dominant on the central Iran.

Loess deposits mainly of silt particles with different mineralogical sources have covered about 10 percent of the Earth land area. World-wide studies on loess deposits show that most of the loess deposits accumulated during the Glacial ages while during the inter-glacial phases their accumulation has stopped or dramatically lessened. Loess deposits have recorded the past climatological history within their grains which can be used to distinguish possible climate changes during the Quaternary period. Dating of paleo-proxy records such as loess sediments also have the potential for understanding the chronology of paleo environmental events including tectonic activities. Loess deposits around the world were among the first sediments to be used for luminescence dating particularly within the arid and semi-arid areas.
The development of luminescence dating techniques and our understanding of loess palaeosol sequences have progressed over the past 35 years with both fields of study supporting the development and understanding of the other. Luminescence dating dosimeters are grains of feldspar and quartz, which are both typically abundant in loess, and, because loess is a fine-grained aeolian deposit and its nature implies medium-to-long transport distances, any previous luminescence signal should be reset (or ‘removed’) prior to deposition. Luminescence dating is also an important tool for developing numerical chronologies for loess deposits, providing comparison of different records and the study of correlations between records. Furthermore, the event being dated is the last exposure of the sediments to daylight, which directly relates the luminescence age to the time of deposition of the sediment.
Study and dating of loess deposits from different parts of Iran can help to test this hypothesis. Several investigations on loess deposits from North and North-eastern Iran (including North of Alborz Mountains, Gorgan and Gonbad Kavous) led to limited chronological results. On the other hand, although loess sediments have been distinguished in different parts of central Iran (i.e. Kerman and Yazd provinces) there was not a single study of loess deposits in this area so far. As a result, we decided to attempt a research on loess deposits of central Iran. One of important areas of loess remains in central Iran is Maibod area located in central part of Yazd Province. Maibod is located in the main high-way towards the Persian Gulf region. Loess deposits formed as local ridges accumulated on an extended fault-erosional terrace in southern side of Maibod. Since study and dating of such deposits can clarify parts of tectonic history of Maibod area the outcome from such research is correct can be crucial. Furthermore, investigation on loess deposits of such dating-free location can significantly add to its Quaternary Paleoenvironmental/Paleoclimatological knowledge.
Consequently, we extracted a sample from parts of loess deposits over the Maibod terrace. The extraction point is located on the western side of Maibod City where the loess sediments becoming very hard and they formed wide varieties of yardang to interfluve ridges with a few meters height. Contaminated Quartz grains of 90–180 μm and the post IR single-aliquot regenerative-dose protocol were employed for De determination. Experiments were carried out in Oxford University using a Riso TA-15a automated TL/OSL system (Botter-Jensen, 1997) incorporating an IR laser diode (400mW, 830±5 nm), and a Strontium-90 beta source.
After laboratory works and dating of the sample (at 30000 to 39000 years ago) the accumulation period has been distinguished at around the middle of the last glacial age (Wurm). Considering the major water erosion over both top loess (late Quaternary) and its green marl basement (Neogene) and due to the distinct slope escarpment (terrace-like feature) we can conclude that the accumulation phase was after the last fault activity. In other words, most active seismic event has happened earlier than loess deposition before 3000 to 39000 years ago. Due to the relatively intact feature of nearby ancient Narin castle (3000 years old) we can conclude that the most sever tectonic activities in the area occurred between 3000 to 40000 years ago approximately. Such single conclusion needs to be evaluated with more studies and many OSL dating on loess deposits of central Iran

Catastrophic earthquakes and their consequences have led to specific attention to liquefaction effects during recent years. Within areas with a higher groundwater level, seismic vibration occurring due to an earthquake can decrease the cohesiveness and strength of water-richsand soils and turn them suddenly into liquid materials. Such a process of changing solid materials to liquid ones under seismic effects is called “liquefaction”. Liquefied saturated soils may deform with little shear resistance.This can cause extensive damages to urbanand rural buildings and other structures such as coastal foundations, sea rigs, water resources, wateror gas pipelines, and power pylons. Some parts of Abarkuh county is under liquefaction risk due to morphotectonic conditions and active fault systems, such as the main Dehshir-Baft fault and its accessory branches, young Quaternary deposits with especial geological conditions and existence of extensive undergroundwater. Due to the lack of studies on the liquefaction risk and the significance of preventingany consequent life losses or financial damages in AbarkuhCounty, we try to study the major factors of triggering liquefaction, investigating the areas with higher risk factors.We also make some suggestionsas to reduce probable losses. To evaluate the major factors that affect liquefaction, G.I.S software, and, to determine the high risk areas, a fuzzy logic model are used. After making fuzzy layers to increase the sensitivity of liquefaction zonation mapping, threeGama phases of 0.7, 0.8, and 0.9are used. By comparing different Gama effects, we have decided to execute Gama 0.9 level due to its higher resolution and better coverage on liquefaction zonation. The result of this modeling indicates the location of a 100 km2 area within a high risk factormainly in NE, E and SE parts of the county. The area of moderate risk with about 65 km2 is located in SE and near the central of the county.

Studies have been done; although not frequently, on glacial features of central Iran by foreigners and Iranian researchers which all refer to climate changes during Quaternary period. However, there are controversial opinions about the extents of the changes and temperature and precipitation conditions over central Iran during cold phases (equal to glacial phases) of Quaternary. Although all studies agree with colder conditions during the Late Quaternary, they have differences over the extremity of the weather conditions. Some of the researchers indicate temperatures as low as minus -36° C during colder phases, although some others believe in temperature as low as less than minus 12° C. Some studies signify a drier than today or with no precipitation difference, though with some positive moisture balance and some others believe on a moisture conditions than today. In this research we have investigated the glacial evidence such as: valleys and cirques, moraines and their altitudinal locations, along with statistical analyses to distinguish any probable temperature and precipitation changes during the cold phase in Shir Kuh northern slopes. Using Write method to establish the Wurm firn line we reconstructed the thermal counter intervals within the watershed. Regression correlations used to reconstruct changes on temperature and precipitation compared with contemporary meteorological data.

Sand hills are deposits which are formed at hillsides of some hills and mountains of the desert and semi desert areas. Previously, Sand hills were known as the product of wind processes. New studies show that although the role of wind has the first importance degree in emergence of such phenomenon but other processes including hill side and water processes are involved in its development. How the formation and accumulation of wind material and then the involvement of other geomorphologic factors and processes, with a certain layers compaction of hill side and flowing material (alluvial), each one are considered as the indicators of the past climatic or environmental conditions. Since the importance of this phenomenon has not been considered in geomorphologic studies of natural geography of Iran, therefore the purpose of this paper is to study and review the significant features of this phenomenon and introducing it to natural geography society of Iran. The study of physical conditions, settlement shape and sediment structure of such phenomenon in different geographical situations enable us to access useful information such as direction and intensity of wind blowing, trend of climatic change, erosion condition in the area and even the impact of some tectonic events and hill side movements.For more description of this phenomenon, while summing up the library studies, some examples of field studies in Yazd province have been indicated.