Investigating the development of conglomeratic karsts based on field and laboratory studies (case study: Tange Shabikhun region, Khoramabad city)

Authors

1 Associate Professor of Engineering Geology, Faculty of Basic Sciences, Lorestan University, Khorramabad, Islamic Republic of Iran

2 Ph. D., Student Sedimentology and Sedimentary Rocks, Bu Ali Sina University, Hamedan, Iran and Expert of the Central Laboratory of Lorestan University, Khorramabad, Iran

Abstract

One of the significant geological phenomena in the conglomerate of the Amiran formation in Shabikhon area of Khorramabad city is the karst development with different distribution, shapes and sizes, which has created a unique geotourism attraction in this area. Since the development of karst rarely occurred in the coarse-grained detrital facies such as conglomerates, therefore, in the present study, the karsts developed in the conglomerate of Amiran formation in the mentioned area have been investigated using field and laboratory studies. Based on field studies, petrographic characteristics, water seepage along fractures and bedding surfaces, algal cover, dip direction of slope and alkalinity of water were identified as the main agents of karst development in the area. For laboratory studies, the slake durability test and petrographic characteristics were used. The results of the slake durability test (up to 15 cycles) on four various samples of the conglomerate showed that sample with calcite cement (Id15 = 97.56%) had less erosion and decay (Id15 = 86.16–93.98%) than other samples without calcite cement. In addition to effect of the cement type and clay matrix in the erosion and decay of the conglomerates and as a result the karst development, the alkalinity of region water also plays a significant role in the erosion and decay of the conglomerates without calcite cement, and thus more severe development of karst in them compared to those with calcite cement. However, some karsts are formed due to dissolution of calcite cement, which have been less abundant than those formed in other conglomerates without calcite cement. In fact, investigations indicated that conglomeratic karsts are mostly erosional type. Generally, studies results of petrographic and laboratory are in good agreement with field evidence in relation to the way and intensity of the karstification in the study area.

Keywords

New Findings in Applied Geology

Articles in Press, Accepted Manuscript
Available Online from 18 September 2023

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History

  • Receive Date: 05 July 2023
  • Revise Date: 07 September 2023
  • Accept Date: 18 September 2023

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