Document Type : scientific-research article
Author
School of Earth Sciences Damghan University, Damghan, Iran
Abstract
Extended Abstract
1. Introduction
Karst classification is carried out in order to better investigate karsts. It plays a fundamental role in distinguishing and recognizing them. Today, the implementation of development projects without the appreciation of karst classification and recognition seems a difficult task. Field studies, topographic maps, satellite images, aerial photographs and geological maps of Dar Parchin signal the assumption that Karsts in this region are various. Therefore, various methods are needed to identify and classify them. This article aims to classify karsts in Dar Parchin by using various methods and models so that the findings can be used in different studies.
2. Theoretical Framework
Areas covered by calcareous formations and dissolved by the flow of water are known as karstic landscapes. The investigation and classification of these lands are of prime importance since seven to ten percent of the earth surface comprises such areas. Many researchers have focused on the classification of karsts. The classification of this kind was first proposed by Cvijic in 1925. His classification was based on the morphological structure of karsts. The karst classification based on hydrogeological conditions was put forth in 1973 by Komatina. In 2003, Waltham and Fox proposed engineering classification method. Karst classification, based on tectonic activity, was established by Herak in 1977. This article first attempts to identify the existing karsts in Dar Parchin region and then begins to classify them using Cvijic, Waltham, Herak, and Komatina methods. The results could be used in development projects of area.
3. Methodology
To classify karsts in Dar Parchin Basin, the boundaries of this Basin were identified and the karstic shapes were recognized using field studies, geological and topographic maps and satellite images. Then the identified shapes were classified using typical methods of classification. Cvijic method is the oldest classification method of karstic shapes. The basis of this classification is geomorphological conditions, topography, geology and litho logy. Another method is that of Waltham and Fox who proposed engineering classification method. Given its major applicability of the method in construction projects, it is widely acknowledged by civil engineers and hydrologists. In this method, special attention has been paid to dolines. Therefore the major criterion in this classification is the existence or non-existence of dolines. Classification based on the morphological structure of karsts was put forth by Komatina. This classification uses geological, topographical, and hydrological features of basins. Karst classification, based on tectonic activity, was established by Herak in 1977. In tclassification tectonic activity is the most important factor. Accordingly, karsts are divided to two groups: before orogeny and orogeny.
4. Results and Discussion
4-1-The Identification of Karstic Shapes in the Mentioned Region
Prior to any classification of karstic shapes, they need to be identified via a number of methods classification. From among the identified shapes in this region, karstic valleys were the largest and kinds of karrens were the most frequent and varied. The next most varied type was dolines including buried dolines, alluvial dolines and soluble dolines. Besides the mentioned types of karst, other shapes could be also seen, which by and large include karst windows, suction walls, Karst springs, ouvalas, Suction wells and ponors.
4-2-The Classification of Karst Shapes in the Mentioned Region
Given the variety of Karsts in Dar Parchin Basin, a mixture of different methods was used for the purpose of classification. According Cvijic, Dar Parchin karsts fall into transitional karsts since caves are merely developed in this region and poljes that are symbols of karstic terrains could not be found in any spot of Dar Parchin region. According to Waltham classification, due to mountainous climate, incomplete and narrow dolines, shallow gaps, limited spread of caves and the non-existence karstic poljes, this karstic area falls into the category of young karsts. According to Komatina's classification, there is a proper condition of the formation of both types of karsts, namely flat and synclinal karst So, based on this classification, the Karst of region falls in to the flat Karst. According to Herak's classification, given the intensity of folding in this area, the karsts include orogenic karsts and ground karsts.
5. Conclusions and Suggestions
By studying and classifying karstic shapes in Dar Parchin Basin, it was found that karstic valley, kinds of karrens and dolines respectively covered the largest areas in this Catchment. From the viewpoint of karstic classification and according to Switch categorization, Dar Parchin karsts were transitional karst. As per Waltham classification, they were young karst, and with respect to Komatina, they included flat and synclinal karsts and According to Herak's classification, the karsts this Catchment were orogenic karst.
Keywords
Send comment about this article