North African Loess

Area of Interest
North Africa was defined as a Loess Commission ‘Area of Interest’ and it is hoped that studies in this region will develop in the current and subsequent inter-congress periods. We believe that the first reference to loess in North Africa was made by Obruchev in 1914, but if anyone has an earlier reference please make contact. Also if anyone has a translation of the Obruchev 1914 article, this would be much appreciated. Of the ‘early’ references the most critical is probably Rathjens (1928), which influenced Scheidig (1934) to include the Libyan loess in the ‘Nachgewiesen (definite)’ category in his pioneering map.

Of the current references, the key items could be those associated with Coude-Gaussen, in particular her book ‘Les Poussieres Saheriennes’ (1991). We note a recent reference to collapsing loess in Egypt, and a study on the engineering properties of loess in Libya (Assallay et al 1996). We need a general outline map of North Africa showing possible loess locations in Morocco, Algeria, Tunisia, Libya and Egypt. We maybe should include S.Israel in this large loess province. When Smalley & Vita-Finzi (1968) reproduced the Scheidig map they lumped N.Africa and Israel together into region # 4 and this might be an acceptable generalization.

It’s the desert connection which unites the region and therefore some aspects of the literature deal with the ‘desert loess’ problem- how exactly are peri-desert deposits formed? There is a Dirtmap connection- how do these regions function as sources of dust which might affect climate? There is an engineering connection- these N.African deposits show subsidence behaviour like all other collapsing loess ground systems. To do - by Reno 2003 we should have assembled a bibliography and complied a register of projects and investigators, and published more N.African material in Loess Letter. Consult LL44 for loess in Egypt.

References

Assallay, A.M., Rogers, C.D.F., & Smalley, I.J. 1996. Engineering properties of loess in Libya. J.Arid Environments 32, 373-386.

Coude-Gaussen, G. 1991. Les Poussieres Saheriennes. John Libby Eurotext

Obruchev, V.A. 1914. The problem of North African loess. Zemlevedenie 4, 130-135 (in Russian).

Rathjens, C. 1928. Loss in Tripolitanien. Zeit.Ges.Erdk.zu Berlin (for 1928), 211-228.

Scheidig, A. 1934. Der Loss und seine geotechnischen Eigenschaften. Theodor Steinkopff, Dresden u.Leipzig 133p.

Smalley, I.J. & Vita-Finzi,C. 1968. The formation of fine particles in sandy deserts and the nature of ‘desert’ loess. J.Sediment.Petrol. 38, 766-774.