Reconstruction of the Paleo-Environmental Ancient Settlement Using Geomorphological Analysis Case study: Tal-e Malyan (Anshan) of Fars Province
Executor of project: Dr. Raziye Lak
Project Associates: Dr. Asghar Navidfar - Dr. Mehran Maghsoudi - Dr. Seyed Mohammad Zamanzadeh - Dr. Alireza Sardari zarchi
In this research the past environmental conditions have been studied by using field observations, sedimentology, geochemistry and geophysics studies in Tel Malyan area (Anshan), 45 km northwest of Shiraz (Fars province). The purpose of reconstructing the environmental conditions in Tel Malyan area was to identify different sedimentation environments and the impact of each environment on the residents of the area. In the first stage sampling done by field Survey of Trenches and determination the border of site. Sampling included good cover of environmental conditions and sedimentation in different parts of the area. Sedimentation studies include the measurements of sediment texture, the largest size, sedimentation environment, mean, standard deviation, coefficients of skewness and sorting. Geochemical studies are based on measuring parameters: soil acidity, redox, salinity, organic matter, chemical index, clay mineralogy. Due to the physical properties and sediment texture of the Trenches, geophysical studies were performed to identify the old river channels. The results of the sedimentology section indicate the existence of a lake and river environment in the area. There were drainage networks inside and outside the large the area. Evidence of river environments was identified in Trenches of 18, 11, 9, 8. The results of the geophysical section confirm the existence of river channels. Sediment texture in Trenches 18, 11, 9, 8 was generally identified as gravel, muddy gravel, gravel of mixed sand and mud. Specifically, the sediment texture in the lower layers of this borehole is deposited in the environment with constant water flows and the upper layers are related to flood periods and in drier environmental conditions. Lake evidence was clearly identified in the lower layers of borehole 18 and borehole 2. The reasons for existence of the lake were the traces and remains of bivalves and gastropods inside the sediments of these Trenches. Based on the geochemical results, the soils of the area are divided into three groups of hydromorphic, calcareous and sodium soils, respectively. In this area, the soils of the eastern margin were mostly affected by water and the color of sediments in this area was generally gray and white. The results of x-ray Fluorescence (XRF) data in borehole 18, as the most significant natural borehole in Tel Malyan area, show five trends of increasing and decreasing humidity.Clay mineralogy was performed for 57 samples of sediments. According to the results, 26 samples of Palygorskite mineral were in the first and second order in terms of frequency and only in 31 samples other minerals had the highest frequency. The highest frequency of Palygorskite mineral was identified in the southern and eastern parts of the area. The dominance of Palygorskite mineral indicates the dry and semi-arid environmental conditions in the region.