Читать книгу Continental Rifted Margins 1 - Gwenn Peron-Pinvidic - Страница 18

Narrow rifts (Buck 1991) are characterized by a thinning in the crust and lithospheric mantle over a relatively narrow zone of about 100–150 km wide (Figure 1.4). The formation of narrow rifts is attributed to local weakening factors such as thermal thinning, strain weakening and local magmatism, where deformation is focused at the weakest or thinnest region of the lithosphere (Kusznir 1987; Buck 1991, 2004). The resulting rifts developed under this extensional mode are characterized by distinct lateral gradients in crustal thickness, topography and heat flow (Bonatti 1985; Corti et al. 2003). Archetypal examples of narrow rifts are the East African Rift system (Chorowicz 2005), the Rhine Graben (Brun et al. 1992; Dèzes et al. 2004), the Baikal Rift (ten Brink Taylor 2002), the Rio Grande Rift (van Wijk et al. 2018) and the Gulf of Suez-Red Sea Rift (Ragab and El-Kaliouby 1992; Bosworth et al. 2021).

Figure 1.4. Illustration of the “narrow rift mode” introduced by Buck (1991). In this extensional case, the lithospheric thinning affects a narrow zone of up to 100–150 km wide