The Pelusium Megashear System across Africa and associated lineament swarms

Abstract

The Pelusium megashear system (Neev, 1977) extends from the ‘border zone’ of Anatolia, along the eastern Mediterranean and across Africa from the Nile Delta to the delta of the Niger in the Gulf of Guinea. It appears to continue beyond Africa, via the Atlantic equatorial fracture zones, into the Amazon Basin. It has functioned as a system of en echelon left‐lateral megashears since Precambrian times. At least four other geosutures also cross Africa, paralleling the Pelusium system and similarly continuing into the Atlantic as fracture zones. Swarms of lineaments observed in LANDSAT image mosaics of central and northeast Africa are associated with the Pelusium megashear system. They are interpreted to be of tectonic origin. Linear dunes and yardangs oriented parallel to the lineaments appear to have been formed by winds deviated and channeled by the tectonic lineaments. These eolian features should not be considered therefore as reliable indicators for higher‐altitude atmospheric circulation. Whereas the patterns of the swarms are affiliated to that of the Pelusium megashear system, they are not related to most of the other nearby geologic features. Both the Pelusium megashear system and its associated lineament swarms exhibit northeastward convergence patterns, which suggest counterclockwise rotation of the crust. These probably result from left‐lateral shear movements within the asthenosphere which have continued since the Precambrian.

Origin of the Sinai–Negev erg, Egypt and Israel: mineralogical and geochemical evidence for the importance of the Nile and sea level history

“…All investigators who have studied the SinaieNegev erg have recognized that there are a number of different dune forms in this sand sea (Tsoar, 1974(Tsoar, , 1984(Tsoar, , 1989Neev et al, 1982;Sneh and Weissbrod, 1983;Rubin et al, 2008;Tsoar et al, 2008;Roskin et al, 2011aRoskin et al, , 2011bRoskin et al, , 2012Hermas et al, 2012). By far the most common landforms are linear dunes (Fig.…”

“…MODIS image courtesy of Jeff Schmaltz, MODIS Rapid Response Team, NASA GSFC. aeolian sand in Sinai by Neev et al (1982), Sneh and Weissbrod (1983) and Bartov (1990).…”

Petrology of the bimodal Cenozoic volcanism of the Kapsiki plateau (northernmost Cameroon, Central Africa)

“…It has been considered a volcanic alignment made of a succession of horsts and grabens (Ge Áze, 1943;De Âruelle et al, 1983) independent of the Adamawa structure (Fail et al, 1970;Gouhier et al, 1974). Another point of view is that the Cameroon Line is part of the southernmost portion of the Pelusium megashear system which is supposed to extend across Africa, from the Gulf of Guinea to the Nile Delta (Neev et al, 1982). The Cameroon Line and the Adamawa fracture zone have been supposed to represent the more or less well-®tted continental prolongation of the Ascension fracture zone at the beginning of the opening of the South Atlantic Ocean (Sibuet and Mascle, 1978;Sykes, 1978) or at the present time (Cornacchia and Dars, 1983).…”

Mapping of tecto-lineaments and investigate their association with earthquakes in Egypt: a hybrid approach using remote sensing data

“…The first one was an NNW compressional tectonic regime which prevailed at the end of the Late Cretaceous, and resulted in ENE-oriented thrust faults associated with folds. The second was an NÀS compressional stress regime in response to the convergence of Africa and Eurasia, during the Late Neev et al (1982), Makropoulos and Burton (1981), Ben-Menahem (1979), Riad and Meyers (1985) and NEIC (2007).…”