Landforms Evolution and Formation of Pseudo Karst-Related Geotourism Sites of Al Ula Depression, Northwest Saudi Arabia

Authors

  • Ali Abdellatif Mesaed

    Geo-Exploration Techniques Department, Faculty of Earth Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia

    Geology Department, Faculty of Sciences, Cairo University, Giza 12613, Egypt
  • Ammar Abdulmonem Amin

    Engineering and Environmental Geology Department, Faculty of Earth Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia

DOI:

https://doi.org/10.30564/jees.v8i4.12808
Received: 22 November 2025 | Revised: 25 December 2025 | Accepted: 5 January 2026 | Published Online: 3 April 2026

Abstract

Al Ula depression is an oval-shaped oasis of a general NW-SE trend with a maximum length of 50 km and a maximum width of 25 km. Geologically, the area comprises four main rock units, from base to top: Arabian shield rocks, Paleozoic clastic sedimentary cover, Tertiary basic volcanics (Harrat), and Quaternary wadi deposits. The depression was formed by the integration of climatic, lithologic, and structural elements. These elements were dominant during humid rainy periods that operate in highly fractured and faulted clastic sedimentary rocks and the underlying Arabian shield igneous and metamorphic rocks. The processes of weathering and denudation begin from the west and the east along two main NE faults that delineate the western and eastern scarps of the depression. The presence of isolated landforms, inselbergs, and highly weathered Arabian shield supports the formation of the Al Ula depression throughout prolonged periods of etchplanation, pedimentation, and peneplanation. The presence of a black basaltic sheet overlying the Paleozoic clastics led to progressive erosion by scarp retreat and a constant height of the resulting landforms. The presence of vast peneplain areas reflects the attainment of the final stage of the erosional cycle. The present-day landforms and their spatial distribution reflect the final manifestation of arid climatic conditions.

Keywords:

Landforms Evolution; Karst Landforms; Geomorphology of Saudi Arabia; Geotourism Sites; Al Ula Area

References

[1] Johnson, P.R., 2006. Explanatory Notes to the Map of Proterozoic Geology of Western Saudi Arabia. Saudi Geological Survey: Jeddah, Saudi Arabia. Available from: https://faculty.ksu.edu.sa/sites/default/files/Explanatory%20notes%20for%20the%20shield%20SGS-TR-2006-4.pdf

[2] Al-Laboun, A.A., 1986. Stratigraphy and Hydrocarbon Potential of the Paleozoic Succession in Both Tabuk and Widyan Basins, Arabia. In Future Petroleum Provinces of the World. American Association of Petroleum Geologists: Tulsa, OK, USA. DOI: https://doi.org/10.1306/M40454C14

[3] Wahbi A.M., 2014. Sedimentological and Stratigraphic Studies of the Cambro-Ordovician Succession in North-West Saudi Arabia [Master’s Thesis]. King Fahd University of Petroleum & Minerals: Dhahran, Saudi Arabia.

[4] Adaviruku, P.E., Oyatayo, K.T., 2023. Extraction, Mapping, and Analysis of Structural Lineaments Using Geospatial Azimuth-Altitude Ratio Technique on a DEM of a Sub-Catchment of the Upper Benue River Basin, Nigeria. European Journal of Theoretical and Applied Sciences. 1(6), 939–946. DOI: https://doi.org/10.59324/ejtas.2023.1(6).90

[5] El Aref, M.M., El Dougdoug, A., Mesaed, A.A., 1991. Landform evolution and formation of ferricrete duricrusts, El Heiz area, El Bahariya depression, Western Desert. Egyptian Journal of Geology. 34(1–2), 1–39.

[6] Faniran, A., Jeje, L.K., 1983. Humid Tropical Geomorphology. Longman: London, UK.

[7] Jennings, J. N., 1985. Karst Geomorphology. Basil Blackwell: Oxford, UK.

[8] Summerfield, M.A., 1991. Global Geomorphology. Longman: New York, NY, USA.

[9] Jennings, J.N., 1983. Sandstone Pseudokarst or Karst? In Aspects of Australian Sandstone Landscapes. Australian and New Zealand Geomorphology Group: Christchurch, New Zealand. pp. 21–30.

[10] Wray, R.A.L., 1995. Solutional Landforms in Quartz Sandstones of the Sydney Basin [PhD Thesis]. University of Wollongong: Wollongong, Australia.

[11] Zhi Gan, Z., 1980. Karst types in China. GeoJournal. 4(6), 541–570. DOI: https://doi.org/10.1007/BF00214219

[12] Drogue, C., Bidaux, P., 1992. Structural and hydrogeological origin of tower karst in southern China (Lijiang plain in the Guilin region). Zeitschrift für Geomorphologie. 36(1), 25–36. DOI: https://doi.org/10.1127/zfg/36/1992/25

[13] Migoń, P., 2021. Sandstone geomorphology—Recent advances. Geomorphology. 373, 107484. DOI: https://doi.org/10.1016/j.geomorph.2020.107484

[14] Barreto, H.N., Braucher, R., Salgado, A.A.R., et al., 2022. A karstic model of the generation of tablelands landscapes in sandstones in Eastern Amazonia. Journal of South American Earth Sciences. 114, 103709. DOI: https://doi.org/10.1016/j.jsames.2021.103709

[15] Robert, W., 1997. Quartzite dissolution: Karst or pseudokarst? Cave and Karst Science. 46(2), 81–87.

[16] Duszyński, F., Kacprzak, A., Jancewicz, K., et al., 2024. Towards a Better Understanding of Subsurface Processes in the Evolution of Sandstone Tablelands—Patterns and Controls of Contemporary Sand Removal from Sandstone Caprock, Stołowe Mountains Tableland, SW Poland. Geosciences. 14(12), 356. DOI: https://doi.org/10.3390/geosciences14120356

[17] Osborn, G., 1985. Evolution of the late Cenozoic inselberg landscape of Southwestern Jordan. Palaeogeography, Palaeoclimatology, Palaeoecology. 49(1–2), 1–23. DOI: https://doi.org/10.1016/0031-0182(85)90002-1

[18] Amin, A.A., Mesaed, A.A., 2023. The Role of the Geologic and the Geomorphologic Factors in the Formation of Some Geotourism Sites of Saudi Arabia. In: Allan, M., Dowling, R. (Eds.). Geotourism in the Middle East, Geoheritage, Geoparks and Geotourism. Springer International Publishing: Cham, Switzerland. pp. 193–234. DOI: https://doi.org/10.1007/978-3-031-24170-3_13.

[19] Cathelineau, M., Boiron, M.-C., Grimaud, J.-L., et al., 2023. Pseudo-Karst Silicification Related to Late Ni Reworking in New Caledonia. Minerals. 13(4), 518. DOI: https://doi.org/10.3390/min13040518

[20] Mareš, J., Bruthans, J., Studencová, A., et al., 2024. Moisture patterns and fluxes in evolving tafoni developed in arkosic sandstone in temperate climate. Earth Surface Processes and Landforms. 49(12), 3706–3720. DOI: https://doi.org/10.1002/esp.5928

[21] Migoń, P., Goudie, A., Allison, R., et al., 2005. The origin and evolution of footslope ramps in the sandstone desert environment of south-west Jordan. Journal of Arid Environments. 60(2), 303–320. DOI: https://doi.org/10.1016/j.jaridenv.2004.03.011

[22] Yuan, R., Kennedy, D.M., Stephenson, W.J., et al., 2024. The influence of weathering processes on microtopographic changes of sandstone under simulated upper intertidal conditions from weekly to monthly scales. Geomorphology. 455, 109209. DOI: https://doi.org/10.1016/j.geomorph.2024.109209

[23] Mammoliti, E., Cupido, M., Teloni, R., et al., 2024. Implementation of a non-destructive method to assess weathering deterioration of sandstones in cultural heritage. Bulletin of Engineering Geology and the Environment. 83(4), 110. DOI: https://doi.org/10.1007/s10064-024-03601-4

[24] Sen, S., Freedman, J., Al-Musabeh, A.H., et al., 2025. An Overview Geoheritage of AlUla, Saudi Arabia: From World Heritage Site to Potential Global Geotourism Destination. Geoheritage. 17(4), 130. DOI: https://doi.org/10.1007/s12371-025-01177-3

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How to Cite

Mesaed, A. A., & Amin, A. A. (2026). Landforms Evolution and Formation of Pseudo Karst-Related Geotourism Sites of Al Ula Depression, Northwest Saudi Arabia. Journal of Environmental & Earth Sciences, 8(4), 1–22. https://doi.org/10.30564/jees.v8i4.12808

Issue

Vol. 8 , Iss. 4 (April 2026)

Article Type

Article

License

Copyright © 2026 Ali Abdellatif Mesaed, Ammar Abdulmonem Amin

Creative Commons License

This is an open access article under the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) License.

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