The effect of bedrock and soluble materials on the formation of scallops in Namksar salt cave and Sarab limestone cave

Document Type : Research paper

Authors

1 Professor, Applied Geology Department, Water Research Center, Kharazmi University, Karaj, Iran.

2 Ms. in Hydrogeology, Faculty of Earth Sciences, Kharazmi University, Karaj, Iran.

3 Professor, Applied Geology Department, Faculty of Earth Sciences, Kharazmi University, Karaj, Iran.

Abstract

Scallops are oyster-shell-shaped depression in cave walls, floors and ceilings. Scallops are hydraulic phenomenon which may be used to indicate Past flow direction and other hydraulic parameters, in the caves. Scallops are asymmetrical in the direction of flow, with a smooth slope on the downstream side of the scallop and a steep cusp on the upstream side. Production of scallops is based on the turbulent flow of a solvent over a soluble surface. In nature, this occurs most frequently with water dissolving limestone or with air dissolving ice. In some cases, scallops may form in the chloride or gypsum caves.   In the formation of scallops that are formed by water flow, the hydraulic and chemical characteristics of water flow as well as the type of bedrock are effective in the morphology of scallops.To investigate the effect of bedrock and water-soluble materials on the formation of scallops, a salt and limestone caves with scallops were compared.The results show that due to the larger dimensions of the mirages of Sarab Cave compared to Namksar Cave, the flow velocity in Sarab Cave was slower.The Reynolds number in both caves is almost the same and the flow velocity in Sarab Cave was 17 times higher than in Namksar Cave, but the discharge was almost the same in both caves.Also, the sedimentation (settling) rate in Namaksar cave was 1.8 times faster than Sarab cave.The importance of this article is that for the first time a study on the comparison between salt scallops and limestone scallops was conducted.

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References

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Hydrogeology
Volume 9, Issue 2
Publisher
March 2024
Pages 55-64

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