Sustainable Earth Review
Volume:1 Issue: 4, Oct 2021

In order to study the lithostratigraphy, biostratigraphy, microfacies, depositional setting and also to reconstruct the paleo-environmental conditions of the Tirgan Formation, three outcrop sections were selected in the western part of the Kopet-Daghh sedimentary basin. These sections locate at the Estarkhi village (30 km East of Shirvan city), the Jozak (40 km West of Bojnourd city) and the Zaw Mountain (45 km far from the Kalaleh city). Geographical coordinates of these outcrop sections are: 57o, 51’, 31’’ longitude and 37o, 11’, 29’’ latitude in Estrakhi section, 56o, 42’, 25’’ longitude and 37o, 24’, 55.8’’ latitude in Jozak section, and finally, 55o, 45’, 10.6’’ longitude and 37o, 31’, 20’’ latitude in Zaw section. The Tirgan Formation has a thickness of 129 m in Estarkhi, 362 m in Jozak and 639 m in Zaw section, in which measured and samples to be used in this study. A total number of 62, 102 and 226 rock samples was taken respectively from the Estarkhi, Jozak and Zaw sections, and used for the microscopic studies. Therefore, a total number of 700 thin-sections were prepared from the rock samples and studied under the microscope. In Estarkhi section, the Shurijeh Formation is overlain conformably by the Tirgan Formation. Moreover, the upper contact of the Tirgan Formation with the upper rock unit, the Sarcheshmeh Formation, is continues and conformable. In this outcrop section, the Tirgan Formation begins with siliciclastic deposits with intercalations of marls, representing a gradational passage from the continental Shurijeh Formation to the marine deposits of the Tirgan Formation. The Jozak section represents a conformable and continues contact between the Tirgan Formation with the underlying Shurijeh Formation, but, its upper contact with the overlying Abderaz Formation is cut by a fault. In Zaw section, the lower contact of the Tirgan Formation with the Zard Formation is continues and conformable, but, its upper contact with the younger deposits is covered and unclear. Based on the distribution of facies belts, three paleogeographical maps were prepared for the study area. They are: Hauterivian?-lower Barremian, lower Barremian-upper Barremian and upper Barremian-lower Aptian. Analysis of these maps shows that during the Hauterivian?-lower Barremian, in the far eastern part of the study are (e.g. Estarkhi section), the Tirgan Formation includes in siliciclastic deposits with some marine marls, in that the detrital sediments was carried to the foreland basin as a result of erosion of high structures. In the same time, the western parts of the study area was covered by deposits belonging to a tidal-flat depositional setting, representing a deepening trend from the East towards the West of the area. During the Barremian (lower Barremian-upper Barremian), a major deepening trend has occurred for the both vertical and horizontal extend regionally in the study area. Therefore, the Estarkhi area was covered by tidal-flat deposits, and in the same time, the deepening trend was continued towards the west, led to the deposition of shoal and open marine facies in the Jozak and Zaw area. Finally, in the upper Barremian-lower Aptian, a stable condition was govern for the entire area, led to the deposition of orbitolina bearing limestones totally in the study area. Vertical distribution of facies belts shows that the eastern part of the study area (e.g. Estarkhi section), represents a major deepening upward trend during the upper Barremian-lower Aptian, which is comparable with general and global transgressive trends for the Barremian-Aptian interval. But, in the western part (e.g. Jozak and Zaw areas), the bathymetry was often stable, and somehow, shows a shallowing trend, that probably belongs to the role of basement faults and local tectonic activities, creating various accommodation space on the shallow platform setting in this part of the Kopet-Daghh Basin.

Soil is directly linked to climate through the exchange of carbon between the atmosphere and the pedosphere. Anthropogenic-geomorphic disturbances and accelerated soil erosion processes stimulate spatial heterogeneity in the distribution of soil biotic-abiotic components, causing the activation of positive feedback mechanisms that amplify small deviations and encourage large scale dynamics at the landscape level. Interaction between soil erosion processes and landform characteristics are thought to be the major factors contributing to the emergence of spatial heterogeneity in the biophysical and biochemical mechanisms controlling the linkage between the pedosphere and atmosphere. Dryland landscapes contribute a high proportion of CO2 emissions from soil to the atmosphere due to large‐scale heterogeneity in the distribution of vascular plants and surface concentrations of SOC. Here we reviewed recent contributions to the study of biotic and abiotic drivers of spatial heterogeneity in drylands, and we illustrated a holistic perspective of the interactions among soil erosion processes such as water-wind erosion and dryland landforms characteristics and their impacts on instability in the CO2 concentrations of the atmosphere and, subsequently climate change.

The Identification of Karsticity degree of a karstic basin is very important for the management of water resources and tourism in a region. The purpose of this research is to identify the degree of karsticity of a karstic basin using geomorphologic, empirical, and hierarchical analysis. The research tool includes a topographic map of kalat 1: 50000, a geological map of kalat 1: 100000, aerial photographs of 1: 40000, Google Earth satellite imagery, ARC GIS software, GPS device, meter, compass, Hammock Smith and a digital camera. The results of the study showed that using field evidence, the diversity of landforms is relatively low, there are no cave deposits, and caves are not developed. In the evolutionary stages of karst using the Waltham and Fookse method, the basin is in a young stage. Using a Cvijic Karstic method, it is in the transitional phase. Using the empirical Corbel equation, the karstic erosion indicates a semi-evolutionary condition of the karst. Calcium rate, in the ICP method and weight percentages of lime in carbonate formations, indicating relatively low calcium purity in the carbonate formations of the basin, indicating the degree of development of karst is towards the young. Finally, using the hierarchical analysis model, the total area of ​​the Kalat basin was 19.04% in the less developed class, 24.57% in the undeveloped class, 42.88% in the middle class and 14.38% in the developed class it has been found that due to the small extent of the developed areas of the basin, it shows the young stage. Using the results obtained from different methods and combining this information, Kalat mountain basin can be developed from the perspective of karst development in the less developed category and the karstization of this basin is at a young stage.

In order to study the fossil contents of the Abderaz Formation for biostratigraphical purposes the 500 meters thick section was sampled at type section. The sequence is mainly made up of grey shales and marls with two units of chalky limestone in upper part. The lower contact of the formation with Aitamir Formation is disconform while the upper contact with Abtalkh is continuous. Fifty six species belonging to 16 genera were identified and four biozones were differentiated. These are: Helvetoglobotruncana helvetica (Sigal)total range Zone, 2-Marginotruncana sigali - Dicarinella primitiva (Premoli Silva and Sliter)Partial range Zone, 3- Dicarinella concavata (Sigal)interval Zone and4-Dicarinella asymetrica (Postuma)total range Zone. Based on, these an age of Turonian-Late Santonian is quoted to the formation. Also it was shown that Helvetoglobotruncana helvetica, the index species for middle Turonian exists at the base of the formation while, in the samples immediately below this belonging to Aitamir Formation Rotalipora appenninica, the index for middel cenomanian was recorded. Therefore, lack of index species for late Cenomanian- early Turonian shows a gap spanning this period between the Aitamir and Abderaz formations. This could be a result of sub Hersinian orogeny.

Iran is one of the five countries in the world with the highest climatic diversity, in the word, in which the existing tourist and natural attractions have a high potential for the development of non-oil revenues. Accordingly, the southern regions of Iran with prominent features in formations belong to different geological periods. Differences in sedimentological features of these formations, especially differences in lithology, have led to the formation of extraordinary geomorphological features that are of great importance in attracting tourism. In these areas, especially the Zagros sedimentary basin, which has expanded with a northwest-southeast trend, various geomorphological structures that are important in the growth of the tourism industry are abundant and pristine and unknown. Genaveh port city of Bushehr province in Zagros basin located in Dezful basin with various Neogene formations and sediments (especially Aghajari Formation) and Quaternary, has special topographic and morphological structures such as mountain ranges, hot springs, sea, etc. There is a high potential of tourist attractions that have remained unknown until now. Most of the studied geomorphological features are located in Aghajari detrital deposits (molasses) that the placement of resistant (sandstone) and unstable sequences (marl and siltstone) leads to the formation of special geomorphological structures in this region. This study examines and introduces the pristine, unknown and natural geotourism landscapes of this region. These diverse geological features, along with rich cultural heritage, have provided the basis for tourism development and the creation of geoparks, which in turn are effective in the development of regional economy and rural areas.

In this study, in order to examine the severity of drought risk in Iran during 18-year period (2001-2018), we used rain meteorological data of 176 synoptic meteorological stations, ground surface temperature product (MOD11C3) and vegetation product (MOD13C2) of Moderate Resolution Imaging Spectro radiometer (MODIS). The study results show that the highest drought severity occurred in 2001 and 2003, in 2001 in spring 85.8% and in the summer of 2003, 93.8% of the country was affected by different degrees of drought. During the 18-year period, the highest percentage of drought was related to mean (45.3%), mild (25%), and severe (8.9%) classes, and no drought (20.79%), respectively. The results indicate that in the whole country, there is no severe drought region in the studied period. According to the map of the rainy regions, Iran's rainfall is highly dependent on the roughness, latitude and frequency of the arrival of synoptic systems in the region. The spatial rainfall map in Iran is well suited to VHI drought maps. The regions that receive less than 100 mm of rainfall represent the real deserts of the country. In these regions, severe drought conditions occur. The rainy regions between 100 and 200 mm, in terms of drought conditions, are in the mean class of drought. The rainy regions with a range of 200 to 300 mm are in the mild class of drought and rainy regions with more than 300 mm are usually not affected by drought stress.