UDC 551.435.84(393.7) Didier Cailhol, Philippe Audra, Carole Nehme, Fadi Henri Nader, Mladen Garašić, Vasile Heresanu, Salih Gucel, Iris Charalambidou, Lauren Satterfield, Hai Cheng & R. Lawrence Edwards: The contribution of condensation-corrosion in the morphological evolution of caves in semi-arid regions: preliminary investigations in the Kyrenia Range, Cyprus The condensation-corrosion process occurs when airflow cools at the contact with colder cave walls. Condensed water becomes aggressive for soluble rocks and corrodes the walls. This process is particularly active close to cave entrances in high thermal gradient zones where external air enters caves. Condensation ap-pears to be important where bat colonies are also present. Bat metabolism and guano decomposition release heat, vapour, and acids. Hence, bat colonies contribute to the increase of condensation-corrosion, especially by providing permanent moisture and chemical aggressiveness. Corrosive air convections produce rounded morphologies, such as ceiling channels, cupolas, and corroded older flowstones. This process has been overlooked in previous research, since related morphologies were often confused with those produced by early phreatic flow. Kyrenia Range in Cyprus has a semi-arid climate. All the studied caves developed along open-fractures. They are located both in recrystal-lized carbonates (limestone and dolostone, such as Smoky and Pigeons Caves), or in gypsum (First Day and Angry Bat Caves). We also studied a maze cave that acted as a spring in gypsum that initially developed under phreatic conditions, followed by an epiphreatic phase that allowed the development of notches (Fig Tree Cave, also named İncirli Show Cave). Due to the semi-arid climate, external air is very dry in summer, thus condensation seems to occur mainly in winter, when cave atmosphere instability allows large air exchanges between caves and surface atmosphere. In summer, evaporation prevails, allowing the development of popcorn lines in carbonate caves and massive gypsum crusts, stalagmites, and sidewalk rims in gypsum caves. However, the presence of a bat colony in a semi-confined chamber in Smoky Cave is probably the origin of the permanent moisture, also during the dry season, leading to a strong development of condensation-corrosion features such as ceiling cupolas, and possibly to the permanent activity of flowstones. In addition, we detected high concentrations of sulphur dioxide (SO2) and radon (Rn) in Fig Tree Cave, possibly related to the activity of the neighbouring overthrust. Based on the five studied caves in the Kyrenia Range and surroundings, the open-fracture caves in carbonates and gypsum have not undergone the typical initial phreatic stage, but have formed in a short time during Pleistocene as a result of the fast uplift of the range and were later reshaped by condensation-corrosion morphologies. Some gypsum caves may have formed entirely by this latter process, after initial minor fracture development. Cyprus is an outstanding area for studying the condensation-corrosion in caves, since a phreatic origin can be ruled out for most of the rounded morphologies.
|Translated title of the contribution||The contribution of condensation-corrosion in the morphological evolution of caves in semi-arid regions: Preliminary investigations in the kyrenia range, cyprus|
|Number of pages||23|
|State||Published - 2019|
Bibliographical noteFunding Information:
This study was conducted as part of the project ‘The Caves of Kyrenia Mountains Project: Research, Conservation, and Education’ (Gucel 2018), supported by the European Union “Cypriot Civil Society in Action V” program (contract number: 2015/371-989), the US Embassy in Nicosia, and the University of Rouen with the IRHIS funding for BQR-SHS 2018 grant. The research was led by Mağara Meraklıları Derneği (“Cave Enthusiasts NGO”) in Nicosia, the University of Nicosia, and by the Union Internationale de Spéléologie (UIS; headquar- ter in Slovenia). We thank Mustafa Meraklı for abundant logistical support and for guiding us to the entrances of most caves studied here, the Spéléo-club du Liban (SCL) and the Croatian Speleological Federation (HSS) for co-operation on the field and for caves surveying. We also thank Ludovic Mocochain and Art Palmer for discussions during the preparation of this paper and Christian Dodelin for the identification of bat species. Finally, the thoughtful comments of reviewers greatly helped improve the manuscript.
- Cave microclimatology
- Fast tectonic uplift
- Kyrenia Range-Cyprus