Mythos 71 – Ancient Saharan Lakes

 

Paleoclimatologists have discovered evidence that the Sahara was wet and fertile around 14,500 to 8,000 years ago, and again between 6,600 and 4,700 years ago.(1)William J. Burroughs (2007) Climate Change in Prehistory: the end of the reign of chaos During the Last Glacial Maximum the Sahara desert was more extensive than it is now with the extent of the tropical forests to its south being greatly reduced.(2)Jonathan Adams, “Africa during the last 150,000 years,” Environmental Sciences Division, ORNL Oak Ridge National Laboratory Around 14,500 year ago, the amount of dust in the cores of peat from the period suddenly plummets indicating a period of much wetter conditions in the Sahara.(3)John Whittow (1984) Dictionary of Physical Geography, Page 67 During this time, huge paleolakes are believed to have existed in the Sahara, including the largest Paleolake Megachad, which at its peak was 173 m deep and covered an area of roughly 400,000 km², which would have been bigger than the Caspian Sea is today.(4)Nick Drake and Charlie Bristow (2006) “Shorelines in the Sahara: geomorphological evidence for an enhanced monsoon from palaeolake Megachad,” The Holocene, Volume 16, Number 6, Pages 901–911 Carbonate from this paleolake has been carbondated to as old as 12,950 years old, although the lake has been shrinking consistently throughout the past several thousand years, and is currently only around 1,350 km².(5)Eric O. Odada, et al. (2005) “Lake Chad: Experiences and Lessons Learned Brief,” Managing lakes and their Basins for Sustainable Use

The Lakes and Rivers of the Saharan circa 12,000 Years Ago.

The Lakes and Rivers of the Saharan circa 12,000 Years Ago.

To the northeast of Megachad was the 15,000 km² West Nubian Paleolake, in northeastern modern Sudan,(6)H. J. Pachur and F. Rottinger (1996) Evidence for a large extended paleolake in the Eastern Sahara as revealed by spaceborne radar lab images which would have been slightly smaller than Lake Balkhash in Kazakhstan is today. Sediment from this paleolake has been carbon dated to between 9,300 to 3,650 years ago.(7)Paul Hoelzmann, et al. (2001) “Environmental change and archaeology: lake evolution and human occupation in the Eastern Sahara during the Holocene,” Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 169, Issues 3–4, Pages 193–217 This paleolake in known to have drained northwest into modern Libya, based on dried riverbeds in region. To the north of the West Nubian paleolake was the Selima paleolake in the Kiseiba-Tushka depression of southwest Egypt and northwest Sudan. Between 10,000 and 5,000 years ago,(8)James R. Wiseman and Farouk El-Baz editors (2007) Remote Sensing in Archaeology, Page 64 a lake existed which at 68,200 km²,(9)Ted A. Maxwell, et al. (2010) Evidence for Pleistocene lakes in the Tushka region, south Egypt was almost as large as Lake Victoria in East Africa today.

To the northwest of Megachad was the paleolake Agorass N’essoui, which existed in the region around Adrar Bous of northern Niger. Samples from this paleolake have been carbon dated to between 12,700 and 5,000 years ago.(10)G. Delibrias, et al. (1964) “Saclay Natural Radiocarbon Measurements I.” Radiocarbon, Volume 6, Pages 233-2501 During the moist periods the region between Megachad and Agorass N’essoui which is currently the Ténéré Desert, was fertile and home the Kiffian culture between 10,000 and 8,000 years ago, and then the Tenerian culture between 6,600 and 4,700 years ago. Between these cultures the region became inhospitable desert.(11)Nora Schultz (2008-08-14) “Stone Age mass graves reveal green Sahara,” NewScientist To the west of Agorass N’essoui was Haijad Paleolake(12)Z. Guo, et al. (2000) Global and Planetary Change, Number 26, Page 101 in the Taoudeni basin of northern Mali and eastern Mauritania. The Taoudeni basin is one of the largest geological formations in West Africa, and would have been the home to many lakes and marshlands during the Sahara’s moist periods.

Traditional Imazighen Dwellings Deep Underground in Matmâta, Tunisia

Traditional Imazighen Dwellings Deep Underground in Matmâta, Tunisia

To the north of the Agorass N’essoui was the paleolake Mega-Fezzan, in the Fezzan region of southwest Libya. This paleolake reached a maximum size of 120,000 km²,(13)Mustafa J. Salem, et al. (May 9, 2013) “The Fezzan region: an interesting history and a prospect for a brighter future,” Libya Herald significantly larger than Lake Superior in North America is today at 82,413 km². Dried riverbeds in the Fezzan region also shows a number of paleorivers once connected Mega-Fezzan to the Mediterranean Sea in the region of the Gulf of Sirt. A variety of evidence has been uncovered dating this lake to been 11,300 and 4,600 years ago, using carbon dating (C14) and optically stimulated luminescence (OSL).(14)H. J. Pachur and G. Braun (1980) “The Paleoclimate of the Central Sahara, Libya and the Libyan Desert,” Palaeoecology of Africa, Volume 12, Pages 351-364

In the northwest of Africa a series of large lakes existed in the Atlas Mountains, and to the south of the Aurès Mountains, in modern day Algeria and Tunisia. The remains of these large lakes are the chotts of Northwest Africa. Chotts are salt-lakes and salt-marshes that generally dry into salt-plains in the summer. These chotts start in the coastal mountains of western Algeria, and progress downhill and inland, ending with the largest chott, Chott el Djerid in southern Tunisia. Chott el Djerid lays between 10 and 25 meters below the sea level of the Mediterranean, and yet is only disconnected from the Mediterranean by 21 km (13 miles) of sand dunes.(15)Harry Chapin (1913) “A Sea in the Sahara,” National Waterways: A Magazine of Transportation, Volume 1, Number 2, Pages 131–138 Chott el Djerid covers approximately 7,000 km² making it the second largest salt plain in the world, after Salt Lake in Utah (America). To the west of Chott el Djerid is Chott Melrhir in Algeria, which is a salt lake with surface area of 6,700 km² that lays 40 meters (130 feet) below sea level. The catchment are of Chott Melrhir is approximately 68,750 km² meaning that if the chotts were connected to the sea in ancient times, Lake Melrhir would have been approximately the size of Lake Victoria in East Africa.

References   [ + ]

1. William J. Burroughs (2007) Climate Change in Prehistory: the end of the reign of chaos
2. Jonathan Adams, “Africa during the last 150,000 years,” Environmental Sciences Division, ORNL Oak Ridge National Laboratory
3. John Whittow (1984) Dictionary of Physical Geography, Page 67
4. Nick Drake and Charlie Bristow (2006) “Shorelines in the Sahara: geomorphological evidence for an enhanced monsoon from palaeolake Megachad,” The Holocene, Volume 16, Number 6, Pages 901–911
5. Eric O. Odada, et al. (2005) “Lake Chad: Experiences and Lessons Learned Brief,” Managing lakes and their Basins for Sustainable Use
6. H. J. Pachur and F. Rottinger (1996) Evidence for a large extended paleolake in the Eastern Sahara as revealed by spaceborne radar lab images
7. Paul Hoelzmann, et al. (2001) “Environmental change and archaeology: lake evolution and human occupation in the Eastern Sahara during the Holocene,” Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 169, Issues 3–4, Pages 193–217
8. James R. Wiseman and Farouk El-Baz editors (2007) Remote Sensing in Archaeology, Page 64
9. Ted A. Maxwell, et al. (2010) Evidence for Pleistocene lakes in the Tushka region, south Egypt
10. G. Delibrias, et al. (1964) “Saclay Natural Radiocarbon Measurements I.” Radiocarbon, Volume 6, Pages 233-2501
11. Nora Schultz (2008-08-14) “Stone Age mass graves reveal green Sahara,” NewScientist
12. Z. Guo, et al. (2000) Global and Planetary Change, Number 26, Page 101
13. Mustafa J. Salem, et al. (May 9, 2013) “The Fezzan region: an interesting history and a prospect for a brighter future,” Libya Herald
14. H. J. Pachur and G. Braun (1980) “The Paleoclimate of the Central Sahara, Libya and the Libyan Desert,” Palaeoecology of Africa, Volume 12, Pages 351-364
15. Harry Chapin (1913) “A Sea in the Sahara,” National Waterways: A Magazine of Transportation, Volume 1, Number 2, Pages 131–138