Field analogues illustrating the early stage of deformation of shortening structures in salt-bearing orogenic fold-and-thrust belts are not yet well illustrated in literature. The relatively young Messinian salt of the Algerian basin could represent a good case example of such systems. The Algerian Basin is a deep-water Miocene back-arc basin including a layer of mobile Messinian evaporites up to 2 km thick. The Messinian salt was deposited in an already inverted basin, after its extensive stage. Its inversion initiated in the Tortonian, with a N-NW shortening induced by the north-westward motion of the African plate. In this study, we use new 2D multichannel seismic data to identify, classify and map salt structures throughout the central Algerian Basin and re-assess its structural style. We interpret contractional salt tectonic structures, such as buckle folds, squeezed diapirs and related salt sheets as evidence of regional thick-skinned shortening episodes. We conclude that horizontal displacement loading has driven salt deformation within the basin since its deposition. We also show spatial variations in the structural style of the central Algerian Basin, both along- and down-dip. We demonstrate that the initial shortening-related salt deformation in the late Messinian was focussed along the Algerian margin and later shifted outward toward the Balearic margin in the Plio-Quaternary. The shifting of the deformation front is interpreted to be a result of the thickening and strengthening of the overburden. The second peak of deformation may have reactivated faults along the Emile-Baudot escarpment with thick-skinned deformation. We also observe a variation in the intensity of the salt deformation along the margin from SW to NE, which may be due to variable tectonic loading applied along the Algerian margin or the pre-shortening distribution of salt.

中文翻译：

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最近倒置盆地的收缩盐变形：阿尔及利亚中部盆地中新世到当前的盐变形

说明含盐造山带褶皱逆冲带中缩短结构变形早期阶段的现场类似物尚未在文献中得到很好的说明。阿尔及利亚盆地相对年轻的墨西拿盐可以代表这种系统的一个很好的例子。阿尔及利亚盆地是一个深水的中新世弧后盆地，包括一层厚达 2 公里的可移动的墨西尼亚蒸发岩。麦西尼亚盐沉积在一个已经倒置的盆地中，在它的广泛阶段之后。它的反转始于 Tortonian，非洲板块的西北运动导致 N-NW 缩短。在这项研究中，我们使用新的二维多道地震数据来识别、分类和绘制整个阿尔及利亚盆地中部的盐结构，并重新评估其结构风格。我们解释收缩盐构造结构，例如带扣褶皱、挤压底辟和相关的盐片作为区域厚皮缩短事件的证据。我们得出结论，自沉积以来，水平位移载荷驱动了盆地内的盐变形。我们还展示了阿尔及利亚盆地中部构造风格的空间变化，包括沿倾和下倾。我们证明了晚麦西尼期最初与缩短相关的盐变形集中在阿尔及利亚边缘，然后在上里奥第四纪向外移动到巴利阿里边缘。变形前沿的移动被解释为上覆岩层增厚和强化的结果。变形的第二个峰值可能重新激活了沿 Emile-Baudot 悬崖的断层，并具有厚皮变形。