Geothermics and Geomanifestations (2)

A geothermal terrain of outstanding geomanifestations

The Afar Triangle, overlapping the borders of Eritrea, Ethiopia and Djibouti, is a segment of proto-oceanic crust in the Afro-Arabian Rift System where the spreading ridges that are forming the Red Sea and the Gulf of Aden emerge on land and meet the East African Rift. Large areas of the Afar Triangle are lowland plains below sea level (including Lake Asal, the lowest point of Africa at -155 m) and specifically in its northern part, the Danakil Depression, it is one of the hottest and most inhospitable places on Earth.

Extreme evaporation in this drainless depression dotted with shield volcanoes and the hydrothermal processes connected to rifting formed a formidable landscape where different types of extreme environments coexist closely spaced, making the Afar Triangle a conglomeration of exceptionally spectacular and scenic geomanifestations: bubbling lava lakes, multi-coloured hydrothermal fields, hydrothermal vents, salt lakes and dazzling white salt pans.

However, the uniqueness and scenic beauty of these exceptional geosites takes its toll and the myth fades. With the improvement of the infrastructure over the last years geotourism increased and the means of transport of the mined salt bocks changed. The huge camel caravans for salt transport to the markets on the Ethiopian highlands, once landmark of the Danakil Depression, are vanishing, replaced by donkeys and trucks. And even onto Erta’Āle, yet requiring an arduous 4-hours ascent, a road is under construction ….

Click on the collage below to read more about the places as numbered in the map.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Gerold Diepolder
Bavarian Environment Agency (LfU) – Geological Survey, Germany

 

References / Further Reading:

Asrat, A. 2016: The Danakil Depression of Ethiopia. In: Anhaeusser, C.J., Viljoen, M.J. & Viljoen, R.P. (eds.) Africa’s Top Geological Sites. Struik Nature, Cape Town. pp. 189-196.

Cieśluk, K., Karasiewicz, M.T. & Preisner, Z. 2014: Geotouristic attractions of the Danakil Depression. Geotourism, vol. 36, pp. 33-42, http://dx.doi.org/10.7494/geotour.2014.36.33

Dekov, V.M. et al. 2014: Hydrothermal carbonate chimneys from a continental rift (Afar Rift): Mineralogy, geochemistry, and mode of formation. Chemical Geology, vol. 387, pp. 87-100, https://doi.org/10.1016/j.chemgeo.2014.08.019

King, H.M.: Dallol Volcano and Hydrothermal Field. http://www.geology.com/stories/13/dallol/, last assessed January 2019.

Waltham, T. 2016: Extension tectonics in the Afar Triangle. Geology Today, vol. 21/3, pp. 101-107, http://dx.doi.org/10.1007/978-90-481-3055-9_19

 

 

Note: This blog is optimized for viewing in Chrome or Firefox. In other browsers: click on images to display in full resolution.

Leave a Reply